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Eurocode 5 span tables
for solid timber members
in floors, ceilings and roofs for dwellings
4th edition
Licensed copy: univulster, University of Ulster, 21/08/2017, Uncontrolled Copy, © TRADA Technology
Eurocode 5 span tables for solid timber members
4th edition
ISBN: 978-1-909594-14-2
Published in 2014 by BM TRADA
Prepared by Keerthi Ranasinghe and the engineering team at BM TRADA
1st edition published in 2004 by TRADA Technology Ltd and reprinted with amendments in 2005.
ISBN: 1-900510-46-4
2nd edition published and reprinted in 2008 by TRADA Technology Ltd. ISBN: 978-1-900510-59-2
3rd edition published in 2009 by TRADA Technology Ltd. Reprinted with corrections (no changes to
spans) in 2010, 2012, 2013, 2014. ISBN: 978-1-900510-71-4
This is a technical book for professionals in the built environment sector. While every effort is made
to ensure the accuracy of the advice given, the company cannot accept liability for loss or damage
arising from the information supplied
© TRADA Technology Ltd 2014
TRADA Technology is a BM TRADA company
All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or
transmitted in any form, by any means, electronic, mechanical, photocopying, recording or otherwise,
without the prior permission of the copyright owner
BM TRADA
Chiltern House
Stocking Lane
Hughenden Valley
High Wycombe
Buckinghamshire HP14 4ND
tel: +44 (0)1494 569600
fax: +44 (0)1494 565487
email: publications@bmtradagrooup.com
website: www.bmtradagrooup.com
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BM TRADA's Span tables is long recognised as a key resource in timber specification and building. It is
an essential tool for calculating the size of solid, softwood, timber members necessary to give adequate
support to floors, ceilings and roofs in dwellings.
Span tables were originally included in the England and Wales Building Regulations, Approved
Document A: Structure. The tables are still referenced as guidance but the later editions of these tables
have been produced and updated separately by BM TRADA.
Tables are included for domestic floor joists, ceiling joists and binders, rafters, and purlins supporting
rafters for traditional pitched roofs. Calculations are also given for purlins supporting roof sheeting or
cladding, and for flat roof joists, but trussed rafter roofs are excluded.
The tables cover softwood species and grade combinations which satisfy strength classes C16 and C24.
This 4th edition includes revisions for:
• enhanced shear strength: Those spans where shear is the governing criterion have been improved
• enhanced bearing strength: The bearing lengths required have reduced which in turn increased
the clear spans in some instances
• trimmer tables: Span tables for doubled-up trimmer and trimming joists are included and are
consistent with the permanent loading situations of the floor joists tables. Reactions and fastener
tables are included
• changes to some section sizes: An industry survey has prompted changes to the range of member
sizes offered in the tables.
Frequently asked questions are addressed in the notes alongside the tables.
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Eurocode 5 span tables for solid timber members
TRADA, the Timber Research and Development Association, is a not-for-profit, membership-based
organisation delivering key services to members in support of its two main aims of ‘Building markets for
timber’ and ‘Increasing specification’. Membership encompasses companies and individuals across the
entire timber supply/use chain, from foresters and sawmillers, through merchants and manufacturers,
to architects, engineers and specifiers.
For further information and details of membership visit www.trada.co.uk or telephone 01494 569603.
BM TRADA provides independent certification, testing, inspection, training, technical services and
information to the timber, building, fire and furniture industries. It is also the appointed service provider
for TRADA’s research, information and membership administration.
The BM TRADA bookshops offer a wide range of technical publications for professionals:
http://bookshop.bmtrada.com
http://bookshop.trada.co.uk
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Contents
Preface
1
Introduction
1.1
2
10
13
14
15
16
16
16
17
19
Floor joists
Trimmers and trimming joists
19
23
Tables of sizes of ceiling members
55
5.1
6
Loading
Construction and basic workmanship recommendations
Eurocode 5 considerations
Tables of sizes of timber floor members
4.1
4.2
5
Timber availability
Design considerations
3.1
3.2
3.3
4
How to use the span tables
Timber specifications
2.1
3
8
Ceiling joists and binders supporting ceiling joists
Tables of sizes of pitched roof members
6.1
6.2
Rafters and purlins supporting rafters
Purlins supporting roof sheeting or decking
55
60
60
74
7
Tables of sizes of flat roof joists
79
8
References
86
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Eurocode 5
Eurocode
5 span
span tables
tables for
for solid
solid timber
timber members
members
List of tables
Table
Table
Table
Table
Table
Table
Table
Table
1.1
1.2
2.1
3.1
3.2
4.1
4.2
4.3
Table 4.4
Table
Table
Table
Table
Table
4.5
4.6
4.7
4.8
4.9
Table 4.10
Table 4.11
Table 4.12
Table 4.13
Table 4.14
Table 4.15
Table 4.16
Table 4.17
Table 4.18
Table
Table
Table
Table
Table
Table
Table
Table
Table
Table
Table
Table
Table
Table
Table
Table
Table
Table
Table
Table
Table
Table
Table
Table
Table
Table
Table
Table
Table
Table
Table
Table
4.19
4.20
4.21
4.22
4.23
4.24
4.25
4.26
4.27
4.28
4.29
4.30
5.1
5.2
5.3
5.4
6.1
6.2
6.3
6.4
6.5
6.6
6.7
6.8
6.9
6.10
6.11
6.12
6.13
6.14
6.15
6.16
Imposed loads for floors, ceilings and roofs
Summary of tables
Common species/grade combinations which satisfy strength classes C16 and C24 Snow roof loads for the zones defined in Figure 3.1
Strutting or blocking of joists
Domestic floor joists C16 timber
Domestic floor joists
C24 timber
Permissible clear spans of double member trimmers which support trimmed domestic floor joists and
C16 timber
non-loadbearing lightweight partitions not exceeding 1.0 kN/m
Permissible clear spans of double member trimmers which support trimmed domestic floor joists and
non-loadbearing lightweight partitions not exceeding 1.0 kN/m
C24 timber
Nail centres for double member trimmers in Table 4.3 Nail centres for double member trimmers in Table 4.4 Bolt centres for double member trimmers in Table 4.3 Bolt centres for double member trimmers in Table 4.4 Factored (design) reactions in kN at each end of double member trimmer in Table 4.3 with an
incoming partition
Factored (design) reactions in kN at each end of double member trimmer in Table 4.4 with an
incoming partition
Factored (design) reactions in kN at each end of double member trimmer in Table 4.3 without an
incoming partition
Factored (design) reactions in kN at each end of double member trimmer in Table 4.4 without an
incoming partition
Permissible clear spans of double member trimming joists which support a trimmer and non-loadbearing
Dead load 0.25 kN/m²
C16 timber
lightweight partitions not exceeding 1.0 kN/m
Permissible clear spans of double member trimming joists which support a trimmer and non-loadbearing
lightweight partitions not exceeding 1.0 kN/m
Dead load 0.25 kN/m²
C24 timber
Permissible clear spans of double member trimming joists which support a trimmer and non-loadbearing
lightweight partitions not exceeding 1.0 kN/m
Dead load 0.50 kN/m²
C16 timber
Permissible clear spans of double member trimming joists which support a trimmer and non-loadbearing
lightweight partitions not exceeding 1.0 kN/m
Dead load 0.50 kN/m²
C24 timber
Permissible clear spans of double member trimming joists which support a trimmer and non-loadbearing
Dead load 1.25 kN/m²
C16 timber
lightweight partitions not exceeding 1.0 kN/m
Permissible clear spans of double member trimming joists which support a trimmer and non-loadbearing
Dead load 1.25 kN/m²
C24 timber
lightweight partitions not exceeding 1.0 kN/m
Nail centres for double member trimming joists in Table 4.13 Nail centres for double member trimming joists in Table 4.14 Nail centres for double member trimming joists in Table 4.15 Nail centres for double member trimming joists in Table 4.16 Nail centres for double member trimming joists in Table 4.17 Nail centres for double member trimming joists in Table 4.18 Bolt centres for double member trimming joists in Table 4.13 Bolt centres for double member trimming joists in Table 4.14 Bolt centres for double member trimming joists in Table 4.15 Bolt centres for double member trimming joists in Table 4.16 Bolt centres for double member trimming joists in Table 4.17 Bolt centres for double member trimming joists in Table 4.18 Ceiling joists
C16 timber
Ceiling joists
C24 timber
Ceiling binders C16 timber
Ceiling binders
C24 timber
Common or jack rafters
Roof slope 15–22.5°
Imposed load 0.60 kN/m²
C16 timber
Common or jack rafters
Roof slope 15–22.5°
Imposed load 0.60 kN/m²
C24 timber
Purlins supporting rafters
Roof slope 15–22.5°
Imposed load 0.60 kN/m²
C16 timber
Purlins supporting rafters
Roof slope 15–22.5°
Imposed load 0.60 kN/m²
C24 timber
Common or jack rafters
Roof slope 15–22.5°
Imposed load 1.02 kN/m²
C16 timber
Common or jack rafters
Roof slope 15–22.5°
Imposed load 1.02 kN/m²
C24 timber
Purlins supporting rafters
Roof slope 15–22.5°
Imposed load 1.02 kN/m²
C16 timber
Purlins supporting rafters
Roof slope 15–22.5°
Imposed load 1.02 kN/m²
C24 timber
Common or jack rafters
Roof slope 22.5–30°
Imposed load 0.60 kN/m²
C16 timber
Common or jack rafters
Roof slope 22.5–30°
Imposed load 0.60 kN/m²
C24 timber
Purlins supporting rafters
Roof slope 22.5–30°
Imposed load 0.60 kN/m²
C16 timber
Purlins supporting rafters
Roof slope 22.5–30°
Imposed load 0.60 kN/m²
C24 timber
Common or jack rafters
Roof slope 22.5–30°
Imposed load 1.02 kN/m²
C16 timber
Common or jack rafters
Roof slope 22.5–30°
Imposed load 1.02 kN/m²
C24 timber
Purlins supporting rafters
Roof slope 22.5–30°
Imposed load 1.02 kN/m²
C16 timber
Purlins supporting rafters
Roof slope 22.5–30°
Imposed load 1.02 kN/m²
C24 timber
6
10
11
14
16
17
21
22
26
27
28
29
30
31
32
33
34
35
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
57
58
59
59
62
62
63
63
64
64
65
65
66
66
67
67
68
68
69
69
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Table
Table
Table
Table
Table
Table
Table
Table
Table
Table
Table
Table
Table
Table
Table
Table
Table
Table
6.17
6.18
6.19
6.20
6.21
6.22
6.23
6.24
6.25
6.26
6.27
6.28
7.1
7.2
7.3
7.4
7.5
7.6
Common or jack rafters
Roof slope
Common or jack rafters
Roof slope
Purlins supporting rafters
Roof slope
Purlins supporting rafters
Roof slope
Common or jack rafters
Roof slope
Common or jack rafters
Roof slope
Purlins supporting rafters
Roof slope
Purlins supporting rafters
Roof slope
Purlins supporting sheeting or decking
Roof slope
Purlins supporting sheeting or decking
Roof slope
Purlins supporting sheeting or decking
Roof slope
Purlins supporting sheeting or decking
Roof slope
Flat roofs – access for maintenance and repair only
Flat roofs – access for maintenance and repair only
Flat roofs – access for maintenance and repair only
Flat roofs – access for maintenance and repair only
Flat roofs – unlimited access
Flat roofs – unlimited access
30–45°
30–45°
30–45°
30–45°
30–45°
30–45°
30–45°
30–45°
10–30°
10–30°
10–30°
10–30°
Imposed
Imposed
Imposed
Imposed
Imposed
Imposed
Imposed
Imposed
Imposed
Imposed
Imposed
Imposed
Imposed
Imposed
Imposed
Imposed
Imposed
Imposed
load
load
load
load
load
load
load
load
load
load
load
load
load
load
load
load
load
load
0.60
0.60
0.60
0.60
1.02
1.02
1.02
1.02
0.60
0.60
1.02
1.02
0.60
0.60
1.02
1.02
1.50
1.50
kN/m²
kN/m²
kN/m²
kN/m²
kN/m²
kN/m²
kN/m²
kN/m²
kN/m²
kN/m²
kN/m²
kN/m²
kN/m²
kN/m²
kN/m²
kN/m²
kN/m²
kN/m²
C16
C24
C16
C24
C16
C24
C16
C24
C16
C24
C16
C24
C16
C24
C16
C24
C16
C24
timber
timber
timber
timber
timber
timber
timber
timber
timber
timber
timber
timber
timber
timber
timber
timber
timber
timber
70
70
71
71
72
72
73
73
75
76
77
78
80
81
82
83
84
85
List of figures
Figure
Figure
Figure
Figure
Figure
Figure
Figure
Figure
Figure
Figure
1.1 Key to members included in the span tables
3.1 Snow roof loading zones – derived from EC1
4.1 Floor joists arrangement
4.2 Fixings – spacing, edge and end distances
4.3 Plan on double member trimmer supporting trimmed joists
4.4 Plan on double member trimming joist supporting double member trimmer
5.1 Ceiling joists and binder arrangement
6.1 Typical rafters and purlin arrangement
6.2 Purlins supporting roof sheeting or decking
7.1 Typical flat roof joists arrangement
7
10
16
19
24
25
36
56
60
74
79
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Preface
The adoption of Eurocodes is a milestone in harmonising the approach to the design of structures
across Europe. This pan-European approach eliminates an obstacle to trade. It also draws on the
expertise of engineers across all members of The European Committee for Standardization (CEN)
instead of individual member states.
However, there is another big advantage for designers using the Eurocodes. Steel and concrete
designers have used the limit state method for some time while timber designers have retained the
permissible stress method. The evolution of the Eurocodes’ unified approach to design, regardless of
the materials used, means that designers who are already well versed in the design of concrete and
steel structures now have little difficulty working with timber.
These span tables for solid timber members in floors, ceilings and roofs (excluding trussed rafters)
have been produced by BM TRADA to supplement the Approved Document A: Structure for England
and Wales (ADA). From October 2013, the Approved Document A refers to Eurocode 5 (EC5), the
UK National Annex to EC5 (UK NA to EC5) and Published Document 6693 (PD 6693) for the design
of timber buildings. PD 6693 supplements EC5 and the UK NA to EC5 by presenting some of the
information that was lost when migrating to EC5 from BS 5268. The tables cover strength classes C16
and C24 as listed in BS EN 338 Strength Classes.
Timber span tables were included in earlier editions of ADA. When they were taken out of the ADA,
TRADA assumed responsibility for maintaining and publishing them. The 2nd edition of TRADA’s
span tables was based on BS 5268 and the third edition was completely revised to comply with
Eurocode 5.
The spans in this 4th edition are calculated in accordance with the Eurocodes, in particular:
BS EN 1995-1-1 Eurocode 5 Design of timber structures. Common rules and rules for building,
NA to BS EN 1995-1-1 UK National Annex to Eurocode 5. Design of timber structures. General.
Common rules and rules for buildings, and
PD 6693-1 Recommendations for the design of timber structures to Eurocode 5: Design of timber
structures. General. Common rules and rules for buildings.
During the transition from British Standards to Eurocodes, designers must ensure they use a consistent
set of standards and it is not advisable to mix and match British Standards and Eurocodes.
This publication deals solely with the loadbearing capacity of the solid timber members. There are many
other aspects that must be considered in designing a floor, ceiling or roof, which are not included here.
In preparing this publication, BM TRADA has assumed that the complete design will be undertaken by
a competent person. The appropriate sections of the Regulations, Approved Documents and relevant
Standards should be consulted for guidance.
These span tables cannot be adapted for hardwoods or engineered timber products. Designers should
specify engineered timber products that are independently certified for which manufacturers should
supply span tables calculated in accordance with EC5.
Changes in this 4th edition
Enhanced shear strength: Changes to BS EN 338 in 2009 included improvements for the shear
strength of both C16 and C24 strength classes. For the majority of instances in the listed spans this had
no effect as the failure was mostly governed by deflection. However, a handful of spans where shear
was the governing criterion before have been improved as a result.
Enhanced bearing strength: UK Code Committee for the Structural Use of Timber has clarified in
PD 6693 the use of compression perpendicular factor kc,90 in relation to simply supported beams. Prior
to this clarification, it was not possible to include the higher values for kc,90 as these spans are produced
for a general situation and not for any specific bearing condition. This edition now uses a kc,90 factor
of 1.5 throughout. As a result, the nominal bearing lengths required have been reduced which in turn
increased the clear spans for certain instances. To obtain meaningful lengths of bearing achieved in
construction, additional bearing lengths of 30mm allowed either side of a support (see EC5 Clause
6.1.5(1)) have not been used except for trimmers and trimming joists.
8
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Preface
Trimmer tables: Span tables for doubled-up trimmer and trimming joists have been re-introduced
in this edition. Trimmer and trimming joist tables were originally published in the 2nd edition but only
covered a limited number of permanent (dead) loading options. The tables presented in this edition are
now consistent with the permanent loading situations of the floor joists tables. Reactions and fastener
tables for trimmers and trimming joists have also been expanded to be in line with the trimmer and
trimming joist tables themselves.
Changes to section sizes: An industry survey has prompted a few changes to the range of member
sizes offered in the tables.
9
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Eurocode 5 span tables for solid timber members
1.0 Introduction
1.0.1
This document gives section sizes and spans of widely available timber members for floors, ceilings,
traditional pitched roofs (excluding trussed rafter roofs) and flat roofs which support the imposed loads
shown in Table 1.1. It applies to buildings used as single occupancy dwellings.
These span tables have been derived in accordance with BS EN 1995-1-1 Eurocode 5. Design of
timber structures, General. Common rules and rules for buildings (EC5), its UK National Annex (UK NA
to EC5) and the Published Document 6693 (PD 6693). These documents are collectively referred to as
Eurocode 5 (EC5) throughout this document.
Chapter 8 lists the versions of the various reference documents at the time of publication.
Table 1.1 Imposed loads for floors, ceilings and roofs
Member
Imposed loads not exceedinga:
Floor joists
Uniformly Distributed Load (UDL) in kN/m²
1.5
Ceiling joists & binders
0.25b
Rafters & purlins supporting rafters
0.60 or 1.02c
Purlins supporting rafters
0.60 or 1.02c
Flat roof joists:
access limited
0.60 or 1.02c
1.5
access unlimited
Purlins supporting sheeting or decking
0.6 or 1.02c
a The values are taken from the UK National Annex to BS EN 1991-1-1 (EC1)
b For loft spaces floor loadings should be used
c See Table 3.1
Concentrated Load (CL) in kN
2.0
0.9b
0.9
0.9
0.9
2.0
0.9
1.0.2
The figures and sketches in this document are illustrative only and do not show construction details.
1.0.3
Figure 1.1 illustrates some of the members included in this document and Table 1.2 provides a key to
the members included in the tables.
Ridgeboard
Purlin
Rafter
Gable wall
Ceiling joist
Wall
Ceiling binder
Floor joist
Figure 1.1 Key to members included in the span tables
10
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1 Introduction
Table 1.2 Summary of tables
Construction
Floors
Ceilings
Pitched roofs:
Slope of 15° or more but less
than 22.5°
Pitched roofs:
Slope of 22.5° or more but less
than 30°
Timber members
Imposed loading not exceeding
Strength classes
UDL (kN/m2)
CL (kN)
C16
Joists
1.50
Trimmers
1.50
Slab loading
Table 4.1
(see Section 4.1.3)
2.0
Table 4.3
Table 4.4
Nails for double member trimmers
Table 4.5
Table 4.6
Bolts for double member trimmers
Table 4.7
Table 4.8
Factored reactions at each end
of double member trimmers:
with incoming partition
Factored reactions at each end
of double member trimmers:
no incoming partition
Trimming joists with permanent
(dead) loads = 0.25 kN/m2
Trimming joists with permanent
(dead) loads = 0.50 kN/m2
Trimming joists with permanent
(dead) loads = 1.25 kN/m2
Nails for double member trimming
joists with permanent (dead)
loads = 0.25 kN/m2
Nails for double member trimming
joists with permanent (dead)
loads = 0.50 kN/m2
Nails for double member trimming
joists with permanent (dead)
loads = 1.25 kN/m2
Bolts for double member trimming
joists with permanent (dead)
loads = 0.25 kN/m2
Bolts for double member trimming
joists with permanent (dead)
loads = 0.50 kN/m2
Bolts for double member trimming
joists with permanent (dead)
loads = 1.25 kN/m2
Joists
Table 4.9
Table 4.10
Table 4.11
Table 4.12
0.25
Binders
C24
Table 4.2
1.50
2.0
Table 4.13
Table 4.14
1.50
2.0
Table 4.15
Table 4.16
1.50
2.0
Table 4.17
Table 4.18
Table 4.19
Table 4.20
Table 4.21
Table 4.22
Table 4.23
Table 4.24
Table 4.25
Table 4.26
Table 4.27
Table 4.28
Table 4.29
Table 4.30
0.9a
Table 5.1
Table 5.2
0.25
0.9a
Table 5.3
Table 5.4
Rafters
0.60b
0.9
Table 6.1
Table 6.2
Purlins
0.60
0.9
Table 6.3
Table 6.4
Rafters
1.02c
0.9
Table 6.5
Table 6.6
Purlins
1.02
0.9
Table 6.7
Table 6.8
Rafters
0.60
0.9
Table 6.9
Table 6.10
Purlins
0.60
0.9
Table 6.11
Table 6.12
Rafters
1.02
0.9
Table 6.13
Table 6.14
Purlins
1.02
0.9
Table 6.15
Table 6.16
11
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Eurocode 5 span tables for solid timber members
Table 1.2 Continued
Construction
Pitched roofs:
Slope of 30° to 45°
Pitched roofs:
Purlins supporting sheeting or
decking for roofs with a slope of
10° to 30° inclusive
Flat roofs:
Access for maintenance only
Timber members
Imposed loading not exceeding
Strength classes
UDL (kN/m2)
CL (kN)
C16
C24
Rafters
0.60
0.9
Table 6.17
Table 6.18
Purlins
0.60
0.9
Table 6.19
Table 6.20
Rafters
1.02
0.9
Table 6.21
Table 6.22
Purlins
1.02
0.9
Table 6.23
Table 6.24
Purlins
0.60
0.9
Table 6.25
Table 6.26
1.02
0.9
Table 6.27
Table 6.28
0.60
0.9
Table 7.1
Table 7.2
1.02
0.9
Table 7.3
Table 7.4
Joists
Flat roofs:
Joists
1.50
2.0
Table 7.5
Table 7.6
Full access allowed
a The distributed load and the concentrated load are applied simultaneously in ceilings only.
b 0.60 kN/m2 is the minimum value of imposed load specified by EC1
c1.02 kN/m2 represents the highest snow load for 100m altitudes for a duo pitched roof of 30° (see Table 3.1). This value may be slightly
conservative for lower pitches.
12
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1 Introduction
1.1 How to use the span tables
The objective of the span tables is to indicate the maximum span of a softwood member subject to:
•
•
•
•
•
its application
its spacing
the dead and imposed loads it must support
the moisture environment
the strength grade of the timber.
The application is defined in the table caption.
The dead load is usually a variable within each table. The figures given for the uniformly distributed
dead load are forces which correspond to the following approximate weights of the building element
being supported:
•
•
•
•
0.25 kN/m2 is approximately 25
0.50 kN/m2 is approximately 50
0.75 kN/m2 is approximately 75
1.0 kN/m2 is approximately 100
kg/m2
kg/m2
kg/m2
kg/m2.
The imposed load is that for a dwelling and is set for the whole table.
The moisture environment is defined as the service class. Throughout these tables, the spans are suitable
for service classes 1 and 2. Service class 2 is the more severe and corresponds to ‘external uses where
member is protected from direct wetting’. EC5 gives the same results for service classes 1 and 2.
The tables are offered for strength grade C16 softwoods (a common grade for softwoods grown in
Britain) and C24 softwoods (which are more expensive and are usually imported from northern Europe).
If the span figure is shaded, it means that additional bearing length is needed at the supports.
An asterisk means special circumstances may apply, such as additional joists to support partitions.
In the following example, based on Figure 4.1, 38 x 145mm joists spaced at 600mm centres will span
up to 2.49m when supporting a floor weight up to 25 kg/m2.
Imposed
load
Strength
class
Application
Dead
load
Moisture
environment
Spacing
Additional joists
required to
support partitions
Additional bearing
length needed
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Eurocode 5 span tables for solid timber members
2.0 Timber specifications
2.0.1
Accepted species and grade combinations for allocation to strength classes are given in BS EN 1912.
Table 2.1 below shows species and grade combinations that satisfy strength classes C16 and C24, to
which these span tables relate, and are in common use in the UK. Strength and stiffness values for
strength classes are given in BS EN 338.
An explanation of strength classes and strength grading is given in the TRADA Wood Information Sheet
4-7 Timber strength grading and strength classes.
Table 2.1 Common species/grade combinations which satisfy strength classes C16 and C24
Species
Redwood
Origin
Europe
Whitewood
Europe
Douglas fir
UK
British pine
UK
British spruce
UK
Larch
UK
Sitka spruce
Douglas fir-larch
UK
Canada,
USA
Hem fir
Canada,
USA
Spruce-pine-fir
Canada,
USA
Western
whitewoods
USA
Southern pine
USA
Western red
cedar
Canada
Grading rule
BS 4978
BS EN 14081-1
BS 4978
BS EN 14081-1
BS 4978
BS EN 14081-1
BS 4978
BS EN 14081-1
BS 4978
BS EN 14081-1
BS 4978
BS EN 14081-1
BS 4978
BS 4978
J & P*
BS EN 14081-1
NAMSR**
BS 4978
J & P*
BS EN 14081-1
NAMSR**
BS 4978
J & P*
BS EN 14081-1
NAMSR**
BS 4978
J & P*
BS 4978
J & P*
BS EN 14081-1
NAMSR**
BS 4978
C16
C18=
GS
machine graded direct to strength class
GS
machine graded direct to strength class
SS
machine graded direct to strength class
C22=
C24
SS
SS
SS
machine graded direct to strength class
SS
machine graded direct to strength class
GS
machine graded direct to strength class
SS
GS
No1, No2
machine graded direct to strength class
1450f-1.3E
GS
No1, No2
machine graded direct to strength class
1450f-1.3E
GS
No1, No2
machine graded direct to strength class
1450f-1.3E
SS
Sel
GS
No3
machine graded direct to strength class
1450f-1.3E
SS
SS
SS
Sel
1800f-1.6E
SS
Sel
1800f-1.6E
SS
Sel
1800f-1.6E
No1, No2
SS
Sel***
1800f-1.6E
=
For C18 or C22 grade timber, the tables for C16 timber should be used.
*J & P: Joist and plank grades to NGLA (National Lumber Grades Authority, Canada) and NGRDL (National Grading Rules for
Dimension Lumber, USA) rules.
** NAMSR: North American machine stress-rated lumber.
*** This species/grade combination is listed in BS EN 1912 as C30. The use of spans for C24 are therefore conservative.
2.0.2
A species grade combination from a higher strength class may be used where a lower strength class
has been specified if this does not increase the self-weight loading on other elements which still use a
lower strength class.
2.0.3
These span tables apply to dry-graded timber in dry environments as defined by service classes 1 or 2
to EC5. The timber is graded at an average moisture content of 20%, with no reading to exceed 24%.
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2 Timber specifications
The timber should be transported, stored and installed in the building so that this level of moisture
content is not exceeded.
The timber should be CE marked with the following information:
•
the species or species combination, the grade, and/or the strength class, in the case of a strength
class in accordance with BS EN 338
•
information to identify the certification body overseeing the grading
•
the grading rule eg BS 4978, BS EN 14081-1
•
the word DRY or if kiln dried, KD – or whether surfaced dry or green in North America.
2.0.4
Permissible deviations should be in accordance with BS EN 336.
2.0.5
EC5 does not discuss wane but a reduction in strength can be accommodated through the rules for
notching. No wane is permitted in any of the section sizes included in these tables.
2.1 Timber availability
2.1.1
The section sizes shown in these span tables are those commonly available in the UK. If a supplier
offers sections with sizes within the tolerances of the sizes in these tables, then the spans given in the
tables may be used safely. However, not all the sizes shown are always held in stock at timber and
builders’ merchants. Designers and specifiers should check on availability before specifying a particular
size and should note that non-stock sizes may attract additional cost.
Previous editions of this publication presented the common section sizes available in the UK as
were listed in BS EN 336:2003. However, BS EN 336:2013 does not list section sizes. In light of this,
BM TRADA surveyed the structural softwood market in 2014 to see whether the range of timber sizes in
the 3rd edition reflects what is generally available from timber merchants. The main conclusions were:
•
In regularised sizes, the section depth 97mm is more likely to be 95mm
•
In regularised sizes, the section breadth 75mm is more likely to be 72mm
•
In regularised sizes, section breadth 50mm is uncommon
• There is a greater range of ALS/CLS sizes available
• The ALS/CLS size 38mm x 100mm should be 38mm x 114mm.
The sizes listed in the span tables have changed accordingly in this 4th edition.
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Eurocode 5 span tables for solid timber members
3.0 Design considerations
3.1 Loading
3.1.1
The imposed loads indicated in the span tables have been derived in accordance with BS EN 1991-1-1
Eurocode 1: Part 1-1: Densities, self-weight, imposed loads for buildings and Part
1-3: Snow Loads, and their relevant UK National Annexes, generally referred
to as EC1.
3.1.2
In the use of tables in Sections 6 and 7, the snow loading zones applicable
to roofs at particular sites are given in Figure 3.1.
3.1.3
The imposed roof snow loads shown in Table 3.1 are
applicable only to duo-pitched roofs with a pitch of
30° at altitudes up to 200m from a.m.s.l. Refer to NA
to BS EN 1991-1-3 for other attributes. However,
the tables in Sections 6 and 7 show the spans for
0.6 kN/m2 and 1.02 kN/m2 only.
Snow load zones
1
4
2
5
3
6.5
Figure 3.1 Snow roof loading zones – derived from EC1
Table 3.1 Snow roof loads for the zones defined in Figure 3.1
Zone
1
2
3
Imposed roof snow loads (kN/m²)
Altitudes not exceeding 100m
0.36
0.48
0.60
Altitudes not exceeding 200m
0.59
0.71
0.83
4
0.72
0.95
5
0.84
1.07
6.5
1.02
1.25
3.2 Construction and basic workmanship recommendations
3.2.1
Adequate connections between members should be provided, as specified by the building designer.
3.2.2
Unless proved by calculations, notches and holes in simply supported floor and ceiling joists should be
within the following limits:
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3 Design considerations
Notches should not be deeper than the lesser of 0.125 times the depth of a joist or 35mm, and should
not be cut closer to the support than 0.07 of the span, nor further away from the nearest support than
0.25 times the span. Each end of the joist may be edge notched at either the top edge or the bottom
edge.
Holes should have a diameter not greater than 0.25 times the depth of a joist or 65mm, whichever is
smaller, and should be drilled equidistant from the top and bottom edges of the joist. They should be
not less than 3 diameters (centre to centre) apart and should be located between 0.25 and 0.4 times
the span from the support.
Drilled holes and edge notches in the same beam that comply with the above paragraphs must be
horizontally separated by at least 200mm of full section.
Notches or holes should not be cut in rafters, purlins or binders unless approved by the building
designer.
Rafters restrained by ceiling ties at eaves level may be birdsmouthed at supports to a depth not
exceeding one third of the rafter depth.
Refer to PD 6693 for further details.
3.2.3
Floor joists should be restrained at supports and points along the span using timber herringbone
strutting or solid timber blocking, positioned as shown in Table 3.2. Proprietary herringbone strutting
systems are also available; they should be used in accordance with the manufacturer’s instructions.
Table 3.2 Strutting or blocking of joists
Joist span (m)
Up to 2.5
2.5 to 4.5
Over 4.5
Rows of strutting or blocking between supports
None
1 at mid span
2 at one third span positions
3.2.3.1
Timber herringbone strutting should be at least 38 x 38mm but should not be used where the distance
between joists is greater than 3 times their depth.
3.2.3.2
Solid blocking should be at least 38mm thick.
3.2.3.3
Strutting and blocking should extend at least three-quarters of the joist depth.
3.2.3.4
At each end of a row of strutting the outer joist should be blocked solidly at the perimeter wall.
3.2.4
A traditional cut timber roof (ie one made using rafters, purlins and ceiling joists) generally has sufficient
built in resistance to instability and wind forces. However, the building designer should consider whether
the provision of bracing is appropriate, especially in the case of single-hipped and non-hipped roofs to
detached houses with a pitch greater than 40°. Where required, bracing should be equivalent to that
recommended for trussed rafter roofs in PD 6693.
3.3 Eurocode 5 considerations
3.3.1
Previous versions of these span tables followed the calculation procedure set out in BS 5268-7 (seven
parts). Much of the general information contained in these documents is still valid and hence can serve
as valuable reference. This current edition follows the same principles as given in these documents,
with EC5 and EC1, together with recommendations of the Base Eurocode, BS EN 1990 and the UK
National Annex to BS EN 1990 replacing BS 5268-2 and BS 6399 as appropriate.
3.3.2
For conventional floor build-ups lateral displacement of compressive edge and torsional rotation at
supports of the joists are both prevented due to the timber decking. Therefore, no lateral buckling
possibilities are considered and the relevant factor in EC5, kcrit is assumed to be 1.
3.3.3
Spacing between domestic floor joists is generally less than 600mm for conventional floor build-ups.
Hence the joists are usually assumed to share loads with other joists in the system. Since the commonly
used spacings of 400mm, 450mm and 600mm only are considered in this publication, load sharing can
be assumed. A value of ksys = 1.1 is therefore used where relevant.
3.3.4
In calculating the bearing stresses EC5 allows an enhancement through the use of a modified bearing
length that could be as much as 60mm greater than the actual bearing length depending on the support
conditions used. However, the implementation of this enhancement is too complex to be considered in
this publication and is not used except for trimmers and trimming joists. The compression perpendicular
factor kc,90 in EC5 however is now clarified in PD 6693 and is assumed to be 1.5 for all spans considered.
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Eurocode 5 span tables for solid timber members
3.3.5
Section 7 of EC5 requires that vibration checks are done in addition to deflection calculations for
floor joists. Since such calculations require knowledge of the floor build up, Tables 4.1 and 4.2 do
not include comprehensive vibration checks. However, all the spans listed in Tables 4.1 and 4.2 were
vibration checked using the fundamental frequency requirement of EC5 and the unit point load criteria
of UK NA to EC5. For this, a softwood deck of thickness 18mm was assumed and the density of the
deck was treated as similar to the joists considered. It must be noted however that not all floors match
these assumptions made. Also, vibration is mostly a perception that cannot be accurately modelled
by calculations. See TRADA’s Eurocode 5: Timber design essentials for engineers for guidance on
vibration.
3.3.6
Deflection limit is taken as span/250 for all spans calculated. Consider the creep deformations as given
by EC5 and UK NA to EC5.
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4 Floor members
4.0 Tables of sizes of timber floor members
4.1 Floor joists
Flooring
Floor joist
Cle
ar
sp
an
of
g
cin s
pa ntre
s
ce
ist
Jo een
tw
e
b
joi
st
Support
Figure 4.1 Floor joists arrangement
4.1.1
Tables 4.1 and 4.2 give permissible clear spans of simply supported domestic floor joists of solid timber
for specified loadings, sizes and spacings calculated in accordance with EC5.
4.1.2
The method of calculation makes no allowance for any contribution of the flooring to the load resistance
of the joists.
4.1.3
Shorter spans are more susceptible to the effect of concentrated loads. In these span tables, we have
assumed a ‘slab loading’ effect described in the note below to dissipate concentrated loads to adjacent
parallel elements (following the practice in BS 5268-7.1). If this were not done, the resulting sections
would be significantly different than in the 2nd edition.
The sizes, spacing and spans given in Tables 4.1 and 4.2 will support the dead loads stated in the
tables together with an imposed load not exceeding 1.5 kN/m2.
Note: Previous editions of these span tables followed exactly the procedure set out in BS 5268-7.1.
When BS 5268-7.1 was published, the loading code BS 6399-1 said that for domestic floors the point
load of 1.4kN could be ignored, so BS 5268-7.1 did not apply this. The exemption was probably because,
for spans over 2.4m, the 1.4kN point load never governed the span with domestic floor loading. For
spans less than 2.4m BS 5268-7.1 used a more onerous distributed load called a 'slab load'.
This fourth edition follows the same principle and uses a suitably defined 'slab load'.
4.1.4
For dead loads the traditional assumption was that:
0.25 kN/m² was for suspended ground floors with no plasterboard or partition allowance;
0.5 kN/m² was for intermediate floors with no partition allowance;
1.25 kN/m² was for party or compartment floors with no partition allowance.
However, with modern materials and insulation requirements, it is likely that today’s floors weigh more
than the above, eg 0.6 kN/m2 for an intermediate floor. Trimmer and Trimming Joist tables are therefore
now extended to cover all three load situations above. Calculate the actual weight of the floor and use
the appropriate column in Table 4.1 or 4.2.
Note: TRADA’s online Timbersizer software allows the exact loads be entered to produce the most
economical solution. For more information visit www.trada.co.uk.
4.1.5
Tables 4.1 and 4.2 make no allowance for concentrated or line loads applied by partitions, trimmers or
other similar causes. Lightweight, non-loadbearing partitions which weigh no more than 1.0kN per metre
run and are parallel to the joists may be supported by one or two additional joists placed immediately
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Eurocode 5 span tables for solid timber members
beneath them. The partitions should be fixed through the floor decking into the joist(s) beneath. In
Tables 4.1 and 4.2, one additional joist is generally sufficient. Where two additional joists are needed,
the spans are marked with an asterisk (eg 1.71*). See the note below. For similar lightweight partitions
which run at right-angles to the joists, the maximum spans in the Tables should be reduced by 10%.
The distributed load produced by a full bath can exceed the 1.5 kN/m2 imposed load for which normal
floor joists are designed. Therefore all joists beneath a bath should be doubled. For all other additional
loads, joist sizes should be calculated by a competent person.
Note 1: On the extreme left-hand side of the tables, where joist spacings are at 400mm, each joist only
has to carry 400mm of floor load. At the tabulated spans, the total load carried by some of the joists is
therefore less than 1.0 kN/m (the weight of a partition as a line load). Hence, one additional joist will not
be strong enough to support the partition plus its own self-weight, so two additional joists are needed.
However, at 600mm spacing, one additional joist is easily able to support a partition as the floor load
attributed to 600mm area is greater than 1.0 kN/m.
Note 2: EC1 classifies partition loads depending on their moveability. For the purposes of the spans
in Tables 4.1 and 4.2, the partition was assumed as fixed in position. ie a permanent load. Although
somewhat conservative, 1.0 kN/m is the lowest partition self-weight allowed in EC1.
4.1.6
Unless justified by specialist calculation, the minimum bearing length at supports for floor joists should
be at least 40mm. This is the assumed bearing length for the Tables 4.1 and 4.2. However, for some
of the spans, the calculations suggested providing longer bearing lengths. Where longer bearing is
required, typically for larger sections, it is indicated in the tables by shading. For these spans the
bearing length provided should be increased to at least 50mm. Longer bearing lengths may also be
needed for practical reasons.
4.1.7
Notching and drilling of floor joists should not exceed the limits given in Section 3.2.2.
4.1.8
The section sizes of floor joists given in Tables 4.1 and 4.2 should be machined on the width of the
joist, ie to reduce its depth, to the tolerances specified in BS EN 336, to allow floors and ceilings to be
laid to a level finish.
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4 Floor members
Table 4.1 Permissible clear spans for domestic floor joists
Imposed load not exceeding
Strength Class C16
This table uses
regularised depth
qk = 1.5 kN/m² or Qk = 2.0 kN or 'slab' loading
Service Class 1 or 2
C16
Dead loads gk (kN/m²) excluding self-weight of joist
Size of joist
Spacing of joists (mm)
Breadth
(mm)
gk not more than 0.25
Depth
(mm)
400
450
gk not more than 0.5
gk not more than 1.25
600
400
450
600
400
450
600
Maximum clear span (m)
38
38
38
38
38
38
95
120
145
170
195
220
1.71*
2.37*
2.86*
3.34*
3.83*
4.31*
1.62
2.24*
2.75*
3.21*
3.68*
4.14*
1.40
1.95
2.49
2.91
3.34
3.76
1.61
2.19*
2.69*
3.15*
3.61*
4.06*
1.52
2.08*
2.59*
3.03*
3.47*
3.90*
1.32
1.82
2.33
2.74
3.14
3.54
1.40
1.87
2.35
2.75
3.15
3.55
1.33
1.78
2.23
2.64
3.03
3.41
1.16
1.56
1.97
2.39
2.73
3.08
44
44
44
44
44
44
95
120
145
170
195
220
1.84*
2.49*
3.00*
3.51*
4.02*
4.52*
1.74
2.39*
2.89*
3.38*
3.86*
4.35*
1.51
2.09
2.62
3.06
3.51
3.95
1.72
2.33*
2.83*
3.31*
3.79*
4.26*
1.63
2.22*
2.72*
3.18*
3.64*
4.10*
1.42
1.95
2.46
2.88
3.30
3.72
1.50
1.99
2.47
2.89
3.32
3.73
1.42
1.89
2.37
2.78
3.18
3.59
1.24
1.67
2.10
2.51
2.88
3.25
47
47
47
47
47
47
95
120
145
170
195
220
1.90*
2.55*
3.07*
3.59*
4.10*
4.62*
1.79
2.45*
2.95*
3.45*
3.95*
4.44*
1.56
2.16
2.68
3.13
3.59
4.04
1.77
2.40*
2.89*
3.38*
3.87*
4.36*
1.68
2.28*
2.78*
3.25*
3.72*
4.19*
1.47
2.01
2.52
2.95
3.38
3.81
1.54
2.05
2.53
2.96
3.39
3.82
1.46
1.95
2.43
2.84
3.26
3.67
1.28
1.72
2.16
2.57
2.95
3.32
63
63
63
63
63
63
95
120
145
170
195
220
2.17*
2.80*
3.38*
3.94*
4.51*
5.07*
2.06*
2.70*
3.25*
3.80*
4.34*
4.88*
1.80
2.45
2.96
3.46
3.95
4.45
2.02*
2.64*
3.19*
3.72*
4.26*
4.79*
1.92
2.54*
3.07*
3.58*
4.10*
4.61*
1.68
2.29
2.79
3.26
3.73
4.20
1.74
2.30
2.79
3.27
3.74
4.21
1.66
2.20
2.68
3.14
3.60
4.05
1.47
1.95
2.43
2.85
3.26
3.68
120
145
170
195
220
2.93*
3.52*
4.11*
4.70*
5.28*
2.82*
3.39*
3.96*
4.53*
5.09*
2.56
3.09
3.61
4.13
4.65
2.76*
3.33*
3.89*
4.44*
5.00*
2.66*
3.20*
3.74*
4.28*
4.82*
2.42
2.91
3.41
3.90
4.39
2.42
2.92
3.42
3.91
4.40
2.32
2.81
3.29
3.76
4.23
2.06
2.55
2.98
3.41
3.85
89
114
140
184
235
1.56
2.21*
2.76*
3.61*
4.60*
1.47
2.09*
2.65*
3.47*
4.42*
1.27
1.82
2.40
3.15
4.01
1.47
2.05*
2.60*
3.41*
4.33*
1.39
1.94
2.50*
3.27*
4.17*
1.21
1.70
2.23
2.97
3.78
1.29
1.76
2.25
2.98
3.79
1.22
1.67
2.14
2.86
3.64
1.07
1.47
1.89
2.58
3.29
89
184
4.57*
5.79*
4.49*
5.69*
4.33*
5.49*
3.95
3.96
3.81
3.46
235
4.74*
6.00*
4.18
89
5.01
5.03
4.84
4.41
72
72
72
72
72
ALS/CLS
38
38
38
38
38
5.30
* Two additional joists required - See Section 4.1.5
Nominal bearing increased to 50mm - See Section 4.1.6
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Eurocode 5 span tables for solid timber members
Table 4.2 Permissible clear spans for domestic floor joists
Imposed load not exceeding
Strength Class C24
Service Class 1 or 2
Dead loads gk (kN/m²) excluding self-weight of joist
C24
gk not more than 0.25
Size of joist
Breadth
(mm)
This table uses
regularised depth
qk = 1.5 kN/m² or Qk = 2.0 kN or 'slab' loading
gk not more than 0.5
gk not more than 1.25
Spacing of joists (mm)
Depth
(mm)
400
450
600
400
450
600
400
450
600
Maximum clear span (m)
38
38
38
38
38
38
95
120
145
170
195
220
1.99*
2.64*
3.18*
3.72*
4.26*
4.79*
1.89*
2.54*
3.06*
3.58*
4.10*
4.61*
1.64
2.27
2.78
3.25
3.72
4.19
1.86*
2.49*
3.00*
3.51*
4.02*
4.52*
1.76
2.39*
2.88*
3.37*
3.86*
4.35*
1.54
2.11
2.61
3.06
3.51
3.95
1.61
2.14
2.62
3.07
3.52
3.96
1.53
2.03
2.52
2.95
3.38
3.81
1.34
1.80
2.26
2.67
3.06
3.45
44
44
44
44
44
44
95
120
145
170
195
220
2.14*
2.77*
3.34*
3.90*
4.47*
5.02*
2.02*
2.67*
3.21*
3.76*
4.30*
4.84*
1.76
2.42
2.92
3.42
3.91
4.40
1.99*
2.61*
3.15*
3.69*
4.22*
4.75*
1.89
2.51*
3.03*
3.54*
4.06*
4.57*
1.65
2.25
2.75
3.22
3.68
4.15
1.71
2.27
2.76
3.23
3.70
4.16
1.63
2.16
2.65
3.10
3.55
4.00
1.44
1.92
2.40
2.81
3.22
3.63
47
47
47
47
47
47
95
120
145
170
195
220
2.20*
2.83*
3.41*
3.99*
4.56*
5.13*
2.08*
2.73*
3.28*
3.84*
4.39*
4.94*
1.82
2.48
2.98
3.49
4.00
4.50
2.05*
2.67*
3.22*
3.77*
4.31*
4.85*
1.94
2.57*
3.10*
3.62*
4.15*
4.67*
1.70
2.32
2.81
3.29
3.77
4.24
1.76
2.33
2.82
3.30
3.78
4.26
1.68
2.22
2.71
3.17
3.63
4.09
1.48
1.97
2.45
2.87
3.29
3.71
63
63
63
63
63
63
95
120
145
170
195
220
2.48*
3.12*
3.75*
4.38*
5.00*
5.62*
2.38*
3.00*
3.61*
4.22*
4.82*
5.42*
2.09
2.73
3.29
3.85
4.40
4.95
2.32*
2.94*
3.54*
4.14*
4.73*
5.32*
2.21*
2.83*
3.41*
3.99*
4.56*
5.13*
1.95
2.57
3.10
3.63
4.15
4.67
1.99
2.58
3.11
3.64
4.17
4.69
1.90
2.48
2.99
3.50
4.01
4.51
1.68
2.23
2.71
3.18
3.64
4.10
72
72
72
72
72
120
145
170
195
220
3.25*
3.91*
4.57*
5.22*
5.86*
3.13*
3.77*
4.40*
5.03*
5.65*
2.85
3.44
4.02
4.59
5.17
3.07*
3.70*
4.32*
4.94*
5.55*
2.96*
3.56*
4.16*
4.76*
5.35*
2.69
3.24
3.79
4.34
4.88
2.70
3.25
3.80
4.35
4.90
2.59
3.13
3.66
4.19
4.71
2.35
2.84
3.32
3.81
4.29
89
114
140
184
235
1.82*
2.51*
3.07*
4.02*
5.11*
1.72
2.41*
2.96*
3.87*
4.92*
1.50
2.12
2.68
3.52
4.47
1.71
2.36*
2.90*
3.79*
4.83*
1.62
2.24*
2.79*
3.65*
4.64*
1.41
1.97
2.53
3.31
4.22
1.49
2.01
2.53
3.32
4.23
1.41
1.91
2.43
3.19
4.06
1.24
1.69
2.17
2.89
3.68
184
235
5.26*
6.65*
5.08*
6.42*
4.64
5.88
4.98*
6.31*
4.81*
6.09*
4.39
5.57
4.40
5.58
4.24
5.38
3.86
4.90
ALS/CLS
38
38
38
38
38
89
89
* Two additional joists required - See Section 4.1.5
Nominal bearing increased to 50mm - See Section 4.1.6
22
Licensed copy: univulster, University of Ulster, 21/08/2017, Uncontrolled Copy, © TRADA Technology
4 Floor members
4.2 Trimmers and trimming joists
4.2.1
The tables in this section are:
• Tables 4.3 & 4.4:
Spans of trimmers
• Tables 4.5 & 4.6:
Nail centres
• Tables 4.7 & 4.8:
Bolt centres
• Tables 4.9 to 4.12:
Reaction forces for trimmers
• Tables 4.13 to 4.18: Spans of trimming joists
• Tables 4.19 to 4.24: Nail centres for trimming joists
• Tables 4.25 to 4.30: Bolt centres for trimming joists.
4.2.2
The tables make allowance for supporting lightweight non-loadbearing internal partitions and are
therefore conservative for situations where no partitions occur. Where openings fall outside the range
of the tables presented, trimmers and trimming joists should be calculated in accordance with EC5 and
the UK NA to EC5. It may also be possible to use other engineered wood products such as laminated
veneered lumber (LVL), glued laminated timber (glulam), wood-based I-joists and wood-based
metal-web beams for longer spans.
EC1 classifies partition loads depending on their moveability. For the purposes of the spans in Tables
4.3 to 4.30, the partition was assumed as fixed in position, ie a permanent load. Although somewhat
conservative, 1.0 kN/m is the lowest partition self-weight allowed in EC1.
4.2.3
The nail specification used is:
• for 38mm wide sections: 3.75mm diameter x 75mm long
• for 44mm and 47mm wide sections: 4.00mm diameter x 90mm long
• 63mm, 72mm and 89mm wide sections: 5.00mm diameter x 125mm long.
The bolt specification used is:
• for 38mm, 44mm, 47mm and 63mm wide sections: M12 bolts (min. 3mm x 38mm M12 washers
under head and nut)
• for 72mm and 89mm wide sections: M16 bolts (min. 4mm x 48mm M16 washers under head and
nut).
It may be possible to use other types of fasteners for which capacities have been obtained experimentally
and declared by manufacturers with third party certification.
4.2.4
Unless justified by specialist calculation, the minimum bearing length at supports for trimmers and
trimming joists should be 100mm. However, for some of the spans, the calculations suggested providing
longer bearing lengths. Where longer bearing is required, typically for larger section trimmers, it is
indicated in the tables by shading. For these spans the bearing length provided should be increased to
at least 120mm. Longer bearing lengths may also be needed for practical reasons.
4.2.5
Double member trimmers and trimming joists should be securely fixed together as shown in Figure 4.2
and detailed in Tables 4.5 to 4.8 for trimmers and 4.19 to 4.30 for trimming joists.
4.2.6
As a minimum the fixing centres for double member trimmer and trimming joists should be at centres
of no more than twice the joist spacing. The spacing values in the tables are therefore limited to a
maximum of 1200mm. There should be at least one fastener per double joist.
23
Licensed copy: univulster, University of Ulster, 21/08/2017, Uncontrolled Copy, © TRADA Technology
Eurocode 5 span tables for solid timber members
Fixing on centreline
Two staggered rows of fixings
C
S
S
S
S
2S
S = spacing
a
Fixing type
Minimum dimension (mm)
a
b
b
c
5d
5d
Maximum of 7d or 80mm 4d
4d
Nail (without pre-drilled hole) 15d
Bolt
d – diameter of nail or bolt
b
Figure 4.2 Fixings – spacing, edge and end distances
4.2.7
The factored (design) loads which need to be supported from each end of the double member trimmer
are given in Tables 4.9 to 4.12. The trimmer supports a lightweight partition weighing not more than
1.0 kN/m along its full length. It also supports one end of an incoming partition and an additional joist
parallel to the trimmed joists on the supported floor. Where the trimmer is supported off a double
member trimming joist, the connection should be designed in accordance with EC5 to ensure that
the load from the trimmer is distributed equally between the members of the trimming joist at, or
immediately adjacent to the connection. The fixings for this connection are required in addition to those
given in these tables.
24
Clear span S
Trimmed joist
Double member trimmer
Double member trimming joist or supporting wall
Void or stairwell
Loaded length L
Licensed copy: univulster, University of Ulster, 21/08/2017, Uncontrolled Copy, © TRADA Technology
4 Floor members
Figure 4.3 Plan on double member trimmer supporting trimmed joists
Notes to Trimmer Tables 4.3 to 4.8
The sizes of the double member trimmer shown in Figure 4.3 will support permanent (dead) and variable (imposed) loads
from the following:
• the trimmed floor joists; and
• a lightweight non-loadbearing partition weighing not more than 1.0 kN/m run, supported on the double member
trimmer, and one supported on and parallel to the trimmed joists with an additional joist beneath it, either at the centre
or at the end of the trimmer; and
• a variable (imposed) load not exceeding 1.5 kN/m2, or 2.0 kN at the centre or end of the trimmer.
It is assumed that the floor joists are of similar cross sectional dimensions for any of the trimmers presented in the tables.
Following the floor joist Tables 4.1 and 4.2, the dead load of the floor construction is taken as not exceeding 0.25 kN/m2,
0.50 kN/m2 and 1.25 kN/m2 respectively. These exclude the joist self-weights which are taken into account in the span
calculation.The two joists should be securely fixed together, see Section 4.2.5.
No notching or drilling of a trimmer should be carried out unless proven by calculation, except as necessary to
accommodate the flanges of joist hangers.
25
Licensed copy: univulster, University of Ulster, 21/08/2017, Uncontrolled Copy, © TRADA Technology
Eurocode 5 span tables for solid timber members
Table 4.3 Permissible clear spans of double member trimmers which support
trimmed domestic floor joists and non-loadbearing lightweight partitions not
exceeding 1.0 kN/m
This table uses
regularised depth
gk = 0.25 kN/m2, 0.50 kN/m2, 1.25 kN/m2
Imposed load not exceeding qk = 1.5 kN/m2 or Qk = 2.0 kN
Dead loads
Strength Class C16
C16
Service Class 1 or 2
Permanent (Dead) loads gk (kN/m2) excluding self-weight of joists
gk not more than 0.25
gk not more than 0.50
Trimmer size
Loaded length L (m) on Figure 4.3
2 × (mm × mm) 1.0
2.0
3.0
4.0
5.0
6.0
1.0
gk not more than 1.25
2.0
3.0
4.0
5.0
6.0
1.0
2.0
3.0
4.0
5.0
6.0
Maximum clear span S (m) on Figure 4.3
2 × 38 × 145
2 × 38 × 170
2 × 38 × 195
2 × 38 × 220
2.21
2.66
3.07
3.48
1.92
2.28
2.64
2.99
1.58
1.90
2.22
2.53
–
1.63
1.91
2.19
–
–
–
1.94
–
–
–
–
2.15
2.59
3.00
3.40
1.86
2.21
2.55
2.90
1.53
1.82
2.13
2.43
–
1.56
1.83
2.10
–
–
–
1.86
–
–
–
–
2.02
2.43
2.83
3.20
1.69
2.01
2.33
2.65
1.38
1.64
1.91
2.18
–
1.40
1.64
1.88
–
–
–
1.65
–
–
–
–
2 × 44 × 145
2 × 44 × 170
2 × 44 × 195
2 × 44 × 220
2.35
2.81
3.24
3.66
2.03
2.41
2.79
3.16
1.73
2.07
2.41
2.75
1.49
1.78
2.09
2.39
–
–
1.85
2.12
–
–
–
–
2.29
2.75
3.17
3.58
1.97
2.34
2.70
3.07
1.67
1.99
2.32
2.64
1.43
1.71
2.00
2.29
–
–
1.77
2.03
–
–
–
–
2.15
2.58
2.98
3.37
1.82
2.16
2.49
2.83
1.51
1.79
2.09
2.38
1.29
1.54
1.79
2.05
–
–
1.58
1.81
–
–
–
–
2 × 47 × 145
2 × 47 × 170
2 × 47 × 195
2 × 47 × 220
2.41
2.88
3.31
3.75
2.08
2.47
2.86
3.24
1.80
2.15
2.50
2.86
1.55
1.86
2.17
2.49
–
–
1.93
2.21
–
–
–
–
2.35
2.81
3.24
3.66
2.02
2.40
2.77
3.14
1.73
2.07
2.41
2.74
1.49
1.78
2.08
2.38
–
–
1.84
2.11
–
–
–
–
2.21
2.65
3.05
3.45
1.87
2.22
2.56
2.90
1.57
1.86
2.17
2.47
1.34
1.60
1.86
2.13
–
–
1.65
1.88
–
–
–
–
2 × 63 × 145
2 × 63 × 170
2 × 63 × 195
2 × 63 × 220
2.71
3.19
3.67
4.14
2.33
2.76
3.18
3.60
2.08
2.46
2.85
3.23
1.85
2.21
2.57
2.93
–
–
2.29
2.62
–
–
–
2.38
2.65
3.12
3.59
4.05
2.26
2.67
3.08
3.49
2.01
2.38
2.75
3.12
1.78
2.12
2.46
2.81
–
–
2.19
2.51
–
–
–
2.27
2.49
2.94
3.38
3.82
2.10
2.48
2.85
3.23
1.85
2.18
2.52
2.86
1.60
1.90
2.21
2.52
–
–
1.96
2.24
–
–
–
2.02
2 × 72 × 145
2 × 72 × 170
2 × 72 × 195
2 × 72 × 220
ALS/CLS
2 × 38 × 140
2 × 38 × 184
2 × 38 × 235
2.84
3.34
3.83
4.33
2.45
2.89
3.33
3.77
2.19
2.59
2.99
3.39
1.99
2.37
2.74
3.11
–
2.12
2.47
2.82
–
–
–
2.57
2.78
3.27
3.75
4.24
2.38
2.81
3.23
3.66
2.11
2.50
2.89
3.28
1.92
2.28
2.64
3.00
–
2.03
2.37
2.70
–
–
–
2.45
2.62
3.08
3.54
4.00
2.20
2.60
2.99
3.39
1.94
2.30
2.65
3.00
1.73
2.05
2.38
2.71
–
1.82
2.12
2.41
–
–
–
2.19
2.12
2.89
3.72
1.85
2.48
3.21
1.53
2.08
2.73
–
1.79
2.36
–
–
2.09
–
–
–
2.07
2.83
3.64
1.79
2.40
3.11
1.47
1.99
2.61
–
1.71
2.26
–
–
2.00
–
–
–
1.94
2.66
3.42
1.64
2.19
2.84
1.33
1.80
2.35
–
1.53
2.02
–
–
1.78
–
–
–
2 × 89 × 184
2 × 89 × 235
3.88
4.94
3.37
4.32
3.04
3.91
2.79
3.59
2.59
3.35
–
3.10
3.80
4.84
3.28
4.20
2.94
3.78
2.69
3.47
2.50
3.23
–
2.96
3.59
4.58
3.04
3.89
2.70
3.47
2.46
3.16
2.24
2.91
–
2.64
Interpolation is permitted for values between given loaded lengths.
– Indicates that a single trimmed joist of this cross section will not span the given loaded length. See Table 4.1.
Indicates that nominal bearing to be increased to 120mm. See Section 4.2.4.
26
Licensed copy: univulster, University of Ulster, 21/08/2017, Uncontrolled Copy, © TRADA Technology
4 Floor members
Table 4.4 Permissible clear spans of double member trimmers which support
trimmed domestic floor joists and non-loadbearing lightweight partitions not
exceeding 1.0 kN/m
This table uses
regularised depth
gk = 0.25 kN/m2, 0.50 kN/m2, 1.25 kN/m2
Imposed load not exceeding qk = 1.5 kN/m2 or Qk = 2.0 kN
Dead loads
Strength Class C24
C24
Service Class 1 or 2
Permanent (Dead) loads gk (kN/m2) excluding self-weight of joists
gk not more than 0.25
gk not more than 0.50
Trimmer size
Loaded length L (m) on Figure 4.3
2 × (mm × mm) 1.0
2.0
3.0
4.0
5.0
6.0
1.0
gk not more than 1.25
2.0
3.0
4.0
5.0
6.0
1.0
2.0
3.0
4.0
5.0
6.0
Maximum clear span S (m) on Figure 4.3
2 × 38 × 145
2 × 38 × 170
2 × 38 × 195
2 × 38 × 220
2.52
2.99
3.45
3.90
2.17
2.57
2.97
3.37
1.92
2.29
2.65
3.02
1.74
2.08
2.42
2.75
–
–
2.15
2.47
–
–
–
–
2.46
2.93
3.37
3.81
2.11
2.49
2.88
3.27
1.86
2.21
2.56
2.91
1.66
1.99
2.32
2.65
–
–
2.06
2.36
–
–
–
–
2.31
2.76
3.17
3.59
1.95
2.30
2.66
3.01
1.70
2.02
2.34
2.65
1.49
1.78
2.07
2.36
–
–
1.83
2.09
–
–
–
–
2 × 44 × 145
2 × 44 × 170
2 × 44 × 195
2 × 44 × 220
2.67
3.15
3.63
4.10
2.30
2.72
3.14
3.56
2.04
2.43
2.81
3.19
1.86
2.21
2.56
2.92
–
–
2.35
2.69
–
–
–
2.44
2.61
3.08
3.55
4.01
2.23
2.64
3.04
3.45
1.97
2.34
2.71
3.08
1.79
2.13
2.47
2.81
–
–
2.25
2.57
–
–
–
2.32
2.45
2.91
3.34
3.78
2.06
2.44
2.81
3.18
1.81
2.14
2.48
2.81
1.63
1.93
2.24
2.54
–
–
2.00
2.28
–
–
–
2.06
2 × 47 × 145
2 × 47 × 170
2 × 47 × 195
2 × 47 × 220
2.74
3.23
3.71
4.19
2.35
2.78
3.21
3.64
2.10
2.49
2.88
3.27
1.91
2.27
2.63
2.99
–
–
2.44
2.78
–
–
–
2.53
2.68
3.16
3.63
4.10
2.28
2.70
3.12
3.53
2.03
2.40
2.78
3.15
1.84
2.19
2.53
2.88
–
–
2.34
2.67
–
–
–
2.42
2.51
2.97
3.42
3.86
2.11
2.50
2.88
3.26
1.86
2.20
2.54
2.88
1.68
1.99
2.30
2.61
–
–
2.08
2.37
–
–
–
2.14
2 × 63 × 145
2 × 63 × 170
2 × 63 × 195
2 × 63 × 220
3.03
3.57
4.09
4.62
2.62
3.09
3.56
4.03
2.35
2.78
3.21
3.63
2.14
2.54
2.94
3.34
–
2.36
2.74
3.11
–
–
2.57
2.92
2.97
3.49
4.01
4.52
2.54
3.00
3.46
3.91
2.27
2.68
3.10
3.51
2.07
2.45
2.84
3.22
–
2.27
2.63
2.99
–
–
2.46
2.80
2.80
3.29
3.78
4.27
2.36
2.78
3.20
3.62
2.08
2.46
2.84
3.22
1.89
2.24
2.58
2.93
–
2.06
2.38
2.71
–
–
2.23
2.53
2 × 72 × 145
2 × 72 × 170
2 × 72 × 195
2 × 72 × 220
ALS/CLS
2 × 38 × 140
2 × 38 × 184
2 × 38 × 235
3.17
3.73
4.28
4.82
2.75
3.24
3.73
4.22
2.46
2.91
3.36
3.81
2.26
2.67
3.09
3.50
–
2.49
2.88
3.26
–
–
2.70
3.07
3.11
3.65
4.19
4.72
2.67
3.15
3.62
4.09
2.38
2.82
3.25
3.68
2.18
2.58
2.98
3.38
–
2.39
2.77
3.14
–
–
2.60
2.95
2.93
3.45
3.95
4.46
2.48
2.92
3.36
3.79
2.19
2.59
2.98
3.37
1.99
2.35
2.72
3.08
–
2.18
2.51
2.85
–
–
2.35
2.67
2.42
3.25
4.17
2.09
2.80
3.61
1.85
2.49
3.23
1.67
2.27
2.95
–
2.01
2.65
–
–
2.40
2.36
3.17
4.07
2.03
2.71
3.50
1.79
2.41
3.12
1.60
2.17
2.84
–
1.93
2.53
–
–
2.29
2.22
2.99
3.83
1.88
2.50
3.22
1.64
2.20
2.84
1.44
1.94
2.54
–
1.71
2.25
–
–
2.02
2 × 89 × 184
2 × 89 × 235
4.32
5.50
3.77
4.82
3.41
4.37
3.13
4.03
2.92
3.76
2.75
3.55
4.23
5.39
3.67
4.69
3.30
4.22
3.03
3.89
2.81
3.62
2.64
3.41
4.00
5.10
3.40
4.35
3.03
3.88
2.77
3.55
2.56
3.30
2.40
3.09
Interpolation is permitted for values between given loaded lengths.
– Indicates that a single trimmed joist of this cross section will not span the given loaded length. See Table 4.2.
Indicates that nominal bearing to be increased to 120mm. See Section 4.2.4.
27
Licensed copy: univulster, University of Ulster, 21/08/2017, Uncontrolled Copy, © TRADA Technology
Eurocode 5 span tables for solid timber members
Table 4.5 Nail centres for double member trimmers in Table 4.3
This table uses
regularised depth
gk = 0.25 kN/m2, 0.50 kN/m2, 1.25 kN/m2
Imposed load not exceeding qk = 1.5 kN/m2 or Qk = 2.0 kN
Dead loads
Strength Class C16
C16
Permanent (Dead) loads gk (kN/m2) excluding self-weight of joists
gk not more than 0.25
gk not more than 0.50
Trimmer size
Loaded length L (m) on Figure 4.3
2 × (mm × mm) 1.0
2.0
3.0
4.0
5.0
6.0
gk not more than 1.25
1.0
2.0
3.0
4.0
5.0
6.0
1.0
2.0
3.0
4.0
5.0
6.0
Nail centres S (mm) on Figure 4.2
2 × 38 × 145
2 × 38 × 170
2 × 38 × 195
2 × 38 × 220
440
530
610
690
310
320
320
370
190
210
220
250
–
160
170
180
–
–
–
130
–
–
–
–
430
510
600
670
300
310
360
360
190
220
230
240
–
150
160
170
–
–
–
140
–
–
–
–
400
480
560
630
280
330
330
330
190
200
210
210
–
150
160
170
–
–
–
120
–
–
–
–
2 × 44 × 145
2 × 44 × 170
2 × 44 × 195
2 × 44 × 220
580
700
640
730
330
400
390
390
240
250
260
270
180
190
200
210
–
–
150
160
–
–
–
–
570
680
630
710
320
380
380
380
230
240
250
260
170
190
200
200
–
–
160
150
–
–
–
–
530
640
740
670
360
350
350
400
210
250
260
260
160
170
190
200
–
–
140
150
–
–
–
–
2 × 47 × 145
2 × 47 × 170
2 × 47 × 195
2 × 47 × 220
600
710
660
740
340
350
400
400
250
260
270
280
170
180
190
200
–
–
160
170
–
–
–
–
580
700
640
730
330
390
390
390
240
250
260
270
180
170
180
190
–
–
150
160
–
–
–
–
550
660
610
690
310
360
360
410
220
230
270
270
160
170
180
190
–
–
140
150
–
–
–
–
2 × 63 × 145
2 × 63 × 170
2 × 63 × 195
2 × 63 × 220
900
790
910
1030
460
550
520
590
340
350
400
400
260
270
280
320
–
–
220
230
–
–
–
190
880
780
890
1010
450
530
510
580
330
390
390
390
250
260
300
310
–
–
240
250
–
–
–
200
820
980
840
950
520
490
570
530
300
360
360
400
260
270
270
270
–
–
210
220
–
–
–
200
2 × 72 × 145
2 × 72 × 170
2 × 72 × 195
2 × 72 × 220
ALS/CLS
2 × 38 × 140
2 × 38 × 184
2 × 38 × 235
700
830
950
1080
480
480
550
530
360
370
370
370
240
290
300
310
–
230
220
230
–
–
–
190
690
810
930
1050
470
560
530
600
350
350
360
400
270
280
290
300
–
220
230
240
–
–
–
200
650
770
880
990
440
510
490
560
320
320
370
370
240
250
260
300
–
200
210
210
–
–
–
180
420
570
740
300
350
350
210
230
240
–
160
180
–
–
130
–
–
–
410
560
720
290
340
340
210
220
230
–
170
170
–
–
140
–
–
–
480
530
680
270
310
350
190
220
230
–
150
160
–
–
130
–
–
–
2 × 89 × 184
2 × 89 × 235
770
820
480
480
300
320
230
250
180
190
–
170
940
800
460
460
320
340
240
240
190
200
–
160
890
910
430
480
290
310
220
240
180
190
–
150
For interpolated values from Table 4.3, use the lower spacing from the two corresponding spacings in this table.
– Indicates that a single trimmed joist of this cross section will not span the given loaded length. See Table 4.1.
Nail specifications used; for 38mm wide sections: 3.75mm diameter x 75mm long, for 44mm & 47mm wide sections:
4.00mm diameter x 90mm long and for 63mm, 72mm & 89mm wide sections: 5.00mm diameter x 125mm long.
Each trimmer should be fixed in line with a minimum of two nails at 1/3 span positions.
28
Licensed copy: univulster, University of Ulster, 21/08/2017, Uncontrolled Copy, © TRADA Technology
4 Floor members
Table 4.6 Nail centres for double member trimmers in Table 4.4
This table uses
regularised depth
gk = 0.25 kN/m2, 0.50 kN/m2, 1.25 kN/m2
Imposed load not exceeding qk = 1.5 kN/m2 or Qk = 2.0 kN
Dead loads
Strength Class C24
C24
Permanent (Dead) loads gk (kN/m2) excluding self-weight of joists
gk not more than 0.25
gk not more than 0.50
Trimmer size
Loaded length L (m) on Figure 4.3
2 × (mm × mm) 1.0
2.0
3.0
4.0
5.0
6.0
gk not more than 1.25
1.0
2.0
3.0
4.0
5.0
6.0
1.0
2.0
3.0
4.0
5.0
6.0
Nail centres S (mm) on Figure 4.2
2 × 38 × 145
2 × 38 × 170
2 × 38 × 195
2 × 38 × 220
500
590
680
770
360
360
370
370
240
250
260
270
170
180
200
190
–
–
150
160
–
–
–
–
610
580
670
760
350
350
360
400
230
240
250
260
160
180
190
200
–
–
140
150
–
–
–
–
570
550
630
710
320
320
370
370
210
220
250
260
160
170
180
190
–
–
140
140
–
–
–
–
2 × 44 × 145
2 × 44 × 170
2 × 44 × 195
2 × 44 × 220
660
780
900
810
380
380
440
440
250
300
310
310
200
220
230
240
–
–
180
190
–
–
–
150
650
770
880
800
370
430
430
430
280
290
300
300
190
210
220
230
–
–
170
180
–
–
–
150
610
720
830
750
340
400
400
450
250
260
270
310
200
210
220
230
–
–
160
170
–
–
–
140
2 × 47 × 145
2 × 47 × 170
2 × 47 × 195
2 × 47 × 220
680
800
740
830
390
390
450
450
260
270
280
290
210
220
210
230
–
–
170
180
–
–
–
140
660
780
720
810
380
380
440
440
250
260
300
310
200
210
230
220
–
–
170
190
–
–
–
150
620
740
850
770
350
410
410
400
260
270
280
280
180
190
200
210
–
–
170
180
–
–
–
140
2 × 63 × 145
2 × 63 × 170
2 × 63 × 195
2 × 63 × 220
1010
1180
1020
1150
520
610
590
670
390
390
450
450
300
310
320
330
–
260
270
280
–
–
230
220
980
1160
1000
1130
500
600
570
650
370
380
440
430
290
300
310
350
–
250
260
270
–
–
220
230
930
1090
940
1060
470
550
640
600
340
410
400
450
260
310
320
320
–
250
260
270
–
–
220
220
2 × 72 × 145
2 × 72 × 170
2 × 72 × 195
2 × 72 × 220
ALS/CLS
2 × 38 × 140
2 × 38 × 184
2 × 38 × 235
790
930
1060
1200
540
540
620
600
410
410
420
420
280
290
300
310
–
240
260
270
–
–
220
210
1030
910
1040
1180
530
520
600
580
390
400
400
400
270
320
330
330
–
230
250
260
–
–
210
220
970
860
980
1110
490
580
550
630
360
360
420
420
280
290
300
300
–
240
250
250
–
–
210
220
600
640
690
340
340
400
230
240
260
160
180
210
–
150
160
–
–
130
580
630
670
330
380
380
220
240
250
170
190
200
–
140
150
–
–
130
550
590
760
310
350
400
230
240
250
160
170
190
–
140
140
–
–
120
2 × 89 × 184
2 × 89 × 235
860
910
530
530
340
360
260
280
200
220
180
180
840
890
520
520
320
350
270
270
210
220
170
180
1000
1010
480
540
330
350
250
270
210
210
170
180
For interpolated values from Table 4.4, use the lower spacing from the two corresponding spacings in this table.
– Indicates that a single trimmed joist of this cross section will not span the given loaded length. See Table 4.2.
Nail specifications used; for 38mm wide sections: 3.75mm diameter x 75mm long, for 44mm & 47mm wide sections:
4.00mm diameter x 90mm long and for 63mm, 72mm & 89mm wide sections: 5.00mm diameter x 125mm long.
Each trimmer should be fixed in line with a minimum of two nails at 1/3 span positions.
29
Licensed copy: univulster, University of Ulster, 21/08/2017, Uncontrolled Copy, © TRADA Technology
Eurocode 5 span tables for solid timber members
Table 4.7 Bolt centres for double member trimmers in Table 4.3
This table uses
regularised depth
gk = 0.25 kN/m2, 0.50 kN/m2, 1.25 kN/m2
Imposed load not exceeding qk = 1.5 kN/m2 or Qk = 2.0 kN
Dead loads
Strength Class C16
C16
Permanent (Dead) loads gk (kN/m2) excluding self-weight of joists
gk not more than 0.25
gk not more than 0.50
Trimmer size
Loaded length L (m) on Figure 4.3
2 × (mm × mm) 1.0
2.0
3.0
4.0
5.0
6.0
gk not more than 1.25
1.0
2.0
3.0
4.0
5.0
6.0
1.0
2.0
3.0
4.0
5.0
6.0
Bolt centres S (mm) on Figure 4.2
2 × 38 × 145
2 × 38 × 170
2 × 38 × 195
2 × 38 × 220
1100
1200
1020
1150
630
750
870
990
520
470
550
630
–
400
470
430
–
–
–
380
–
–
–
–
1070
1200
1000
1130
610
730
850
960
500
450
530
600
–
390
450
420
–
–
–
370
–
–
–
–
1010
1200
1200
1060
560
660
770
880
450
540
470
540
–
350
400
460
–
–
–
330
–
–
–
–
2 × 44 × 145
2 × 44 × 170
2 × 44 × 195
2 × 44 × 220
1170 670
1200 800
1200 920
1200 1050
570
680
600
680
490
440
520
590
–
–
460
420
–
–
–
–
1140 650
1200 770
1200 900
1200 1020
550
660
570
660
470
420
500
570
–
–
440
400
–
–
–
–
1070
1200
1200
1200
600
710
830
940
500
590
690
590
420
380
440
510
–
–
390
450
–
–
–
–
2 × 47 × 145
2 × 47 × 170
2 × 47 × 195
2 × 47 × 220
1200 690
1200 820
1200 950
1200 1080
600
710
620
710
510
460
540
620
–
–
480
440
–
–
–
–
1170 670
1200 790
1200 920
1200 1040
570
680
600
680
490
440
520
590
–
–
460
420
–
–
–
–
1100
1200
1200
1200
620
730
850
960
520
620
720
610
440
530
460
530
–
–
410
470
–
–
–
–
2 × 63 × 145
2 × 63 × 170
2 × 63 × 195
2 × 63 × 220
1200 1160 690
1200 910 820
1200 1050 950
1200 1190 1070
610
730
640
730
–
–
570
650
–
–
–
470
1200 1130 660
1200 890 790
1200 1020 910
1200 1160 1040
590
700
610
700
–
–
540
620
–
–
–
560
1200 1040
1200 820
1200 950
1200 1070
610
720
840
950
530
630
730
620
–
–
490
550
–
–
–
500
2 × 72 × 145
2 × 72 × 170
2 × 72 × 195
2 × 72 × 220
ALS/CLS
2 × 38 × 140
2 × 38 × 184
2 × 38 × 235
1200
1200
1200
1200
1200 1090 660
1200 860 780
1200 990 910
1200 1130 1030
–
700
820
700
–
–
–
640
1200
1200
1200
1200
1180 1050 640
1200 830 760
1200 960 880
1200 1090 1000
–
670
780
670
–
–
–
610
1200
1200
1200
1200
1100 970
1200 760
1200 880
1200 1000
570
680
790
900
–
600
700
800
–
–
–
540
–
–
410
–
–
–
1030
1200
1200
–
–
400
–
–
–
970
1200
1130
–
380
500
–
–
350
–
–
–
2 × 89 × 184
2 × 89 × 235
1200 1200 1010 920 860
1200 1200 1200 1190 1110
1200 1200 1200 810
1200 1200 1150 1050
740
960
–
880
1050
1200
1200
610
820
800
500
510
680
–
440
470
–
770
590
800
770
490
490
650
–
420
450
1200 1200 970 890 830
1200 1200 1200 1150 1070
–
740
540
720
940
440
590
580
For interpolated values from Table 4.3, use the lower spacing from the two corresponding spacings in this table.
– Indicates that a single trimmed joist of this cross section will not span the given loaded length. See Table 4.1.
Bolt specifications used; for 38mm, 44mm, 47mm & 63mm wide sections: M12 bolts (min. 3mm x 38mm M12 washers under head & nut),
for 72mm & 89mm wide sections: M16 bolts (min. 4mm x 48mm M16 washers under head & nut).
Each trimmer should be fixed in line with a minimum of two bolts at 1/3 span positions.
30
Licensed copy: univulster, University of Ulster, 21/08/2017, Uncontrolled Copy, © TRADA Technology
4 Floor members
Table 4.8 Bolt centres for double member trimmers in Table 4.4
This table uses
regularised depth
gk = 0.25 kN/m2, 0.50 kN/m2, 1.25 kN/m2
Imposed load not exceeding qk = 1.5 kN/m2 or Qk = 2.0 kN
Dead loads
Strength Class C24
C24
Permanent (Dead) loads gk (kN/m2) excluding self-weight of joists
gk not more than 0.25
gk not more than 0.50
Trimmer size
Loaded length L (m) on Figure 4.3
2 × (mm × mm) 1.0
2.0
3.0
4.0
5.0
6.0
1.0
2.0
gk not more than 1.25
3.0
4.0
5.0
6.0
1.0
2.0
3.0
4.0
5.0
6.0
Bolt centres S (mm) on Figure 4.2
2 × 38 × 145
2 × 38 × 170
2 × 38 × 195
2 × 38 × 220
1200 720
1200 850
1200 990
1200 1120
640
570
660
750
430
510
600
550
–
–
430
490
–
–
–
–
1200 700
1200 830
1200 960
1200 1080
610
550
630
720
410
490
580
520
–
–
410
470
–
–
–
–
1150 640
1200 760
1200 880
1200 1000
560
670
580
660
370
440
510
590
–
–
360
410
–
–
–
–
2 × 44 × 145
2 × 44 × 170
2 × 44 × 195
2 × 44 × 220
1200 760
1200 900
1200 1040
1200 1180
680
800
700
790
460
550
640
580
–
–
460
530
–
–
–
480
1200 740
1200 870
1200 1010
1200 1140
650
780
670
760
440
530
610
700
–
–
440
510
–
–
–
460
1200 680
1200 810
1200 930
1200 1060
600
710
820
700
540
480
550
630
–
–
500
450
–
–
–
410
2 × 47 × 145
2 × 47 × 170
2 × 47 × 195
2 × 47 × 220
1200 780
1200 920
1200 1070
1200 1200
690
820
710
810
630
560
650
740
–
–
480
550
–
–
–
500
1200 760
1200 900
1200 1030
1200 1170
670
800
690
780
610
540
630
710
–
–
580
530
–
–
–
480
1200 700
1200 830
1200 950
1200 1080
610
730
840
720
550
490
570
650
–
–
520
470
–
–
–
420
2 × 63 × 145
2 × 63 × 170
2 × 63 × 195
2 × 63 × 220
1200
1200
1200
1200
1200 780
1030 920
1180 1060
1200 1200
710
840
730
830
–
590
680
770
–
–
640
580
1200
1200
1200
1200
1200 750
1000 890
1150 1030
1200 1170
680
810
700
800
–
560
650
740
–
–
610
560
1200 1170 690
1200 920 820
1200 1060 940
1200 1200 1070
620
740
860
730
–
510
590
670
–
–
550
630
2 × 72 × 145
2 × 72 × 170
2 × 72 × 195
2 × 72 × 220
ALS/CLS
2 × 38 × 140
2 × 38 × 184
2 × 38 × 235
1200
1200
1200
1200
1200 1200 750
1200 970 890
1200 1120 1020
1200 1200 1160
–
820
950
810
–
1200
–
1200
670 1200
760 1200
1200 1190 720
1200 930 850
1200 1080 990
1200 1200 1120
–
790
920
780
–
–
640
730
1200
1200
1200
1200
1200 1090 660
1200 860 780
1200 990 900
1200 1120 1020
–
720
830
940
–
–
780
660
–
400
440
–
–
400
1170
1200
1200
–
380
500
–
–
380
1100 620
1200 830
1200 1070
–
420
440
–
–
330
2 × 89 × 184
2 × 89 × 235
1200 1200 1130 1040 970
1200 1200 1200 1200 1200
910
880
1200 1200 1090 1000 930
1200 1200 1200 1200 1200
880
850
1200 1200 1200 920 850 800
1200 1200 1200 1180 1090 1030
1200
1200
1200
690
930
900
610
620
800
410
560
590
670
900
870
590
600
770
400
540
560
540
540
710
360
480
500
For interpolated values from Table 4.4, use the lower spacing from the two corresponding spacings in this table.
– Indicates that a single trimmed joist of this cross section will not span the given loaded length. See Table 4.2.
Bolt specifications used; for 38mm, 44mm, 47mm & 63mm wide sections: M12 bolts (min. 3mm x 38mm M12 washers under head & nut),
for 72mm & 89mm wide sections: M16 bolts (min. 4mm x 48mm M16 washers under head & nut).
Each trimmer should be fixed in line with a minimum of two bolts at 1/3 span positions.
31
Licensed copy: univulster, University of Ulster, 21/08/2017, Uncontrolled Copy, © TRADA Technology
Eurocode 5 span tables for solid timber members
Table 4.9 Factored (design) reactions in kN at each end of double member
trimmer in Table 4.3 with an incoming partition
Dead loads
This table uses
regularised depth
gk = 0.25 kN/m , 0.50 kN/m , 1.25 kN/m
qk = 1.5 kN/m2 or Qk = 2.0 kN
2
2
2
Imposed load not exceeding
Strength Class C16
C16
Permanent (Dead) loads gk (kN/m2) excluding self-weight of joists
gk not more than 0.25
gk not more than 0.50
Trimmer size
Loaded length L (m) on Figure 4.3
2 × (mm × mm) 1.0
2.0
3.0
4.0
5.0
6.0
1.0
2.0
3.0
4.0
gk not more than 1.25
5.0
6.0
1.0
2.0
3.0
4.0
5.0
6.0
Factored (design) reactions in kN at each end of double member trimmer with an incoming partition
2 × 38 × 145
2 × 38 × 170
2 × 38 × 195
2 × 38 × 220
5.87 7.21 8.80 –
–
6.48 8.35 10.16 11.73
–
7.04 9.48 11.57 13.35 –
7.60 10.63 12.99 14.93 16.72
–
–
–
–
5.81 7.04 8.54 –
–
6.40 8.15 9.87 11.40
–
6.95 9.25 11.22 12.91 –
7.50 10.36 12.58 14.46 16.15
–
–
–
–
5.65
6.19
6.73
7.25
6.57 7.97 –
–
7.57 9.16 10.57 –
8.60 10.38 11.95 –
9.62 11.57 13.30 14.92
–
–
–
–
2 × 44 × 145
2 × 44 × 170
2 × 44 × 195
2 × 44 × 220
6.06 7.58 9.42 10.86 –
6.70 8.78 10.91 12.56 –
7.29 9.98 12.43 14.30 15.97
7.88 11.19 13.96 16.04 17.91
–
–
–
–
5.99 7.40 9.16 10.57 –
6.61 8.55 10.59 12.19 –
7.20 9.71 12.02 13.86 15.48
7.78 10.88 13.48 15.49 17.34
–
–
–
–
5.82 6.97 8.50 9.85 –
6.40 8.04 9.78 11.31 –
6.95 9.11 11.10 12.76 14.33
7.50 10.19 12.42 14.26 15.93
–
–
–
–
2 × 47 × 145
2 × 47 × 170
2 × 47 × 195
2 × 47 × 220
6.16 7.74 9.71
6.79 8.97 11.25
7.40 10.20 12.83
8.01 11.44 14.41
11.23
–
12.95 –
14.75 16.52
16.55 18.47
–
–
–
–
6.08 7.56 9.44 10.89 –
6.71 8.75 10.92 12.57 –
7.31 9.95 12.43 14.29 15.96
7.90 11.15 13.95 16.02 17.88
–
–
–
–
5.90 7.11 8.78 10.14 –
6.49 8.21 10.08 11.65 –
7.06 9.31 11.44 13.15 14.76
7.62 10.42 12.81 14.70 16.48
–
–
–
–
2 × 63 × 145
2 × 63 × 170
2 × 63 × 195
2 × 63 × 220
6.58 8.52 10.92
7.26 9.88 12.65
7.95 11.28 14.39
8.69 12.67 16.14
12.86 –
–
14.90 –
–
17.00 18.96 –
19.10 21.29 23.38
2 × 72 × 145
2 × 72 × 170
2 × 72 × 195
2 × 72 × 220
ALS/CLS
2 × 38 × 140
2 × 38 × 184
2 × 38 × 235
2 × 89 × 184
2 × 89 × 235
12.48 –
–
14.44 –
–
16.45 18.35 –
18.47 20.59 22.52
6.30 7.84 9.96
6.94 9.07 11.49
7.57 10.30 13.03
8.21 11.54 14.58
11.58 –
–
13.29 –
–
15.09 16.92 –
16.91 18.85 20.72
6.78 8.92 11.41 13.70 –
–
7.50 10.36 13.22 15.87 17.78 –
8.22 11.81 15.05 18.05 20.27 –
9.11 13.26 16.88 20.16 22.78 24.91
6.71 8.72 11.12 13.28 –
–
7.40 10.11 12.88 15.38 17.23 –
8.11 11.52 14.64 17.47 19.62 –
8.94 12.93 16.42 19.57 21.93 24.09
6.49 8.19 10.40
7.15 9.48 12.01
7.82 10.78 13.63
8.52 12.09 15.26
12.30 –
–
14.19 15.84 –
16.13 17.99 –
18.00 20.15 22.04
5.75 6.99 8.53 –
–
6.80 8.99 10.96 12.62 –
7.94 11.32 13.85 15.92 17.77
5.69 6.83 8.31 –
–
6.72 8.77 10.63 12.25 –
7.84 11.01 13.38 15.37 17.21
5.54 6.38 7.75 –
–
6.50 8.14 9.82 11.35 –
7.56 10.25 12.32 14.15 15.81
–
–
–
6.50 8.32 10.65
7.16 9.65 12.32
7.85 10.98 14.00
8.53 12.32 15.64
–
–
–
–
–
–
8.34 12.02 15.32 18.37 21.13 –
8.23 11.73 14.91 17.79 20.53 –
7.96 10.98 13.88 16.59 18.83 –
10.52 15.22 19.36 23.21 26.67 29.44 10.33 14.85 18.84 22.44 25.88 28.45 9.80 13.89 17.51 20.88 23.76 25.96
Interpolation is permitted for values between given loaded lengths.
– Indicates that a single trimmed joist of this cross section will not span the given loaded length. See Table 4.1.
32
Licensed copy: univulster, University of Ulster, 21/08/2017, Uncontrolled Copy, © TRADA Technology
4 Floor members
Table 4.10 Factored (design) reactions in kN at each end of double member
trimmer in Table 4.4 with an incoming partition
Dead loads
This table uses
regularised depth
gk = 0.25 kN/m , 0.50 kN/m , 1.25 kN/m
qk = 1.5 kN/m2 or Qk = 2.0 kN
2
2
2
Imposed load not exceeding
Strength Class C24
C24
Permanent (Dead) loads gk (kN/m2) excluding self-weight of joists
gk not more than 0.25
gk not more than 0.50
Trimmer size
Loaded length L (m) on Figure 4.3
2 × (mm × mm) 1.0
2.0
3.0
4.0
5.0
6.0
1.0
2.0
3.0
4.0
gk not more than 1.25
5.0
6.0
1.0
2.0
3.0
4.0
5.0
6.0
Factored (design) reactions in kN at each end of double member trimmer with an incoming partition
2 × 38 × 145
2 × 38 × 170
2 × 38 × 195
2 × 38 × 220
6.29 7.99 10.23
6.93 9.26 11.83
7.55 10.54 13.44
8.18 11.82 15.06
12.24 –
14.17 –
16.11 18.02
18.04 20.23
–
–
–
–
6.21 7.81 9.97
6.85 9.04 11.52
7.46 10.27 13.07
8.07 11.51 14.63
11.88
–
13.73 –
15.63 17.44
17.46 19.55
2 × 44 × 145
2 × 44 × 170
2 × 44 × 195
2 × 44 × 220
6.50 8.38 10.75
7.16 9.72 12.45
7.83 11.06 14.15
8.53 12.44 15.86
2 × 47 × 145
2 × 47 × 170
2 × 47 × 195
2 × 47 × 220
6.59 8.57 10.98
7.27 9.96 12.72
7.95 11.34 14.46
8.72 12.72 16.21
2 × 63 × 145
2 × 63 × 170
2 × 63 × 195
2 × 63 × 220
7.03 9.45 12.08 14.50 –
–
7.79 10.98 14.05 16.80 19.42 –
8.60 12.54 15.99 19.12 22.07 24.76
9.68 14.09 17.95 21.44 24.65 27.75
–
–
–
–
12.88 –
–
14.89 –
–
16.91 19.37 –
18.95 21.69 23.80
6.42 8.19 10.48
7.07 9.48 12.12
7.72 10.79 13.72
8.38 12.10 15.37
12.54 –
–
14.48 –
–
16.43 18.68 –
18.38 20.95 23.00
6.22 7.71 9.80
6.85 8.91 11.30
7.46 10.11 12.80
8.07 11.32 14.31
11.75
–
–
13.51 –
–
15.24 17.18 –
17.01 19.22 21.04
13.15 –
–
15.22 –
–
17.29 19.95 –
19.37 22.34 24.55
6.51 8.36 10.70
7.17 9.69 12.38
7.85 11.03 14.06
8.56 12.37 15.76
12.81 –
–
14.79 –
–
16.79 19.33 –
18.79 21.59 23.73
6.31 7.87 10.01
6.95 9.10 11.54
7.57 10.34 13.08
8.21 11.58 14.63
12.00 –
–
13.80 –
–
15.57 17.70 –
17.39 19.81 21.68
6.95 9.23 11.77 14.12 –
–
7.69 10.71 13.63 16.34 18.79 –
8.46 12.20 15.51 18.57 21.34 24.03
9.50 13.70 17.39 20.81 23.91 26.90
6.02 7.35 9.36 11.00
–
6.63 8.47 10.77 12.65 –
7.21 9.61 12.19 14.34 16.02
7.79 10.75 13.59 16.04 17.90
–
–
–
–
6.74 8.68 11.03 13.16 –
–
7.44 10.06 12.74 15.18 17.51 –
8.15 11.44 14.47 17.21 19.84 22.22
9.01 12.84 16.21 19.26 22.18 24.83
2 × 72 × 145
2 × 72 × 170
2 × 72 × 195
2 × 72 × 220
ALS/CLS
2 × 38 × 140
2 × 38 × 184
2 × 38 × 235
7.25 9.87 12.65 15.15 –
–
7.16 9.64 12.33 14.74 –
–
6.94 9.07 11.52 13.79 –
–
8.07 11.51 14.69 17.56 20.29 –
7.96 11.20 14.30 17.07 19.72 –
7.69 10.52 13.32 15.93 18.29 –
9.01 13.13 16.73 19.99 23.08 25.89 8.84 12.80 16.27 19.42 22.41 25.12 8.44 11.98 15.13 18.00 20.74 23.34
10.17 14.75 18.78 22.42 25.88 29.02 9.96 14.38 18.26 21.77 25.11 28.14 9.47 13.45 16.96 20.15 23.21 25.97
2 × 89 × 184
2 × 89 × 235
9.18 13.36 17.02 20.34 23.50 26.48 9.01 13.04 16.57 19.77 22.83 25.58 8.60 12.21 15.43 18.43 21.15 23.81
11.73 17.01 21.64 25.83 29.69 33.45 11.52 16.54 20.97 24.98 28.81 32.27 10.94 15.53 19.49 23.24 26.63 29.77
6.15 7.74 9.91 11.89
–
–
7.28 9.98 12.75 15.25 17.08 –
8.64 12.59 16.05 19.17 21.52 23.61
6.07 7.57 9.67 11.55
–
–
7.19 9.72 12.40 14.77 16.54 –
8.47 12.24 15.59 18.59 20.79 22.82
5.90 7.12 9.08 10.70 –
–
6.95 9.12 11.55 13.61 15.22 –
8.13 11.45 14.46 17.04 19.00 20.87
Interpolation is permitted for values between given loaded lengths.
– Indicates that a single trimmed joist of this cross section will not span the given loaded length. See Table 4.2.
33
Licensed copy: univulster, University of Ulster, 21/08/2017, Uncontrolled Copy, © TRADA Technology
Eurocode 5 span tables for solid timber members
Table 4.11 Factored (design) reactions in kN at each end of double member
trimmer in Table 4.3 without an incoming partition
Dead loads
This table uses
regularised depth
gk = 0.25 kN/m , 0.50 kN/m , 1.25 kN/m
qk = 1.5 kN/m2 or Qk = 2.0 kN
2
2
2
Imposed load not exceeding
Strength Class C16
C16
Permanent (Dead) loads gk (kN/m2) excluding self-weight of joists
gk not more than 0.25
gk not more than 0.50
Trimmer size
Loaded length L (m) on Figure 4.3
2 × (mm × mm) 1.0
2.0
3.0
4.0
5.0
6.0
1.0
2.0
3.0
4.0
gk not more than 1.25
5.0
6.0
1.0
2.0
3.0
4.0
5.0
6.0
Factored (design) reactions in kN at each end of double member trimmer with an incoming partition
2 × 38 × 145
2 × 38 × 170
2 × 38 × 195
2 × 38 × 220
5.87
6.48
7.04
7.60
6.64 7.00 –
–
7.36 8.09 8.97 –
8.10 9.49 10.57 –
9.24 10.90 12.15 13.24
–
–
–
–
5.81
6.40
6.95
7.50
6.54 6.84 –
–
7.23 7.79 8.64 –
7.93 9.14 10.14 –
8.97 10.49 11.68 12.67
–
–
–
–
5.65
6.19
6.73
7.25
6.24
6.88
7.53
8.23
6.50 –
–
7.21 7.80 –
8.30 9.18 –
9.49 10.52 11.44
–
–
–
–
2 × 44 × 145
2 × 44 × 170
2 × 44 × 195
2 × 44 × 220
6.06
6.70
7.29
7.88
6.88 7.37 8.10 –
7.64 8.83 9.78 –
8.59 10.34 11.51 12.49
9.79 11.87 13.25 14.41
–
–
–
–
5.99
6.61
7.20
7.78
6.77 7.21 7.80 –
7.49 8.51 9.42 –
8.32 9.93 11.07 12.00
9.48 11.39 12.69 13.85
–
–
–
–
5.82
6.40
6.95
7.50
6.49 6.82 7.09 –
7.17 7.70 8.54 –
7.85 9.01 9.98 10.85
8.79 10.32 11.47 12.44
–
–
–
–
2 × 47 × 145
2 × 47 × 170
2 × 47 × 195
2 × 47 × 220
6.16 6.98 7.64 8.46 –
6.79 7.76 9.17 10.17 –
7.40 8.81 10.74 11.96 13.03
8.01 10.04 12.31 13.75 14.97
–
–
–
–
6.08
6.71
7.31
7.90
6.87 7.38 8.12 –
7.63 8.83 9.79 –
8.55 10.34 11.50 12.47
9.75 11.85 13.22 14.38
–
–
–
–
5.90
6.49
7.06
7.62
6.59 6.99 7.37 –
7.28 8.00 8.87 –
7.98 9.35 10.36 11.27
9.02 10.71 11.90 12.98
–
–
–
–
2 × 63 × 145
2 × 63 × 170
2 × 63 × 195
2 × 63 × 220
6.58 7.48 8.83 10.07 –
–
7.26 8.48 10.55 12.10 –
–
7.95 9.87 12.28 14.18 15.43 –
8.64 11.25 14.01 16.26 17.75 19.13
6.50 7.36 8.56 9.70 –
–
7.16 8.24 10.22 11.64 –
–
7.85 9.57 11.89 13.63 14.83 –
8.52 10.90 13.51 15.64 17.05 18.27
6.30 7.06 7.87 8.79 –
–
6.94 7.84 9.39 10.49 –
–
7.57 8.89 10.91 12.27 13.39 –
8.21 10.13 12.45 14.07 15.30 16.47
2 × 72 × 145
2 × 72 × 170
2 × 72 × 195
2 × 72 × 220
ALS/CLS
2 × 38 × 140
2 × 38 × 184
2 × 38 × 235
6.78 7.75 9.31
7.50 8.95 11.11
8.22 10.39 12.92
8.95 11.83 14.74
6.71 7.62 9.02
7.40 8.70 10.76
8.11 10.10 12.52
8.83 11.50 14.28
6.49 7.28 8.30 9.50 –
–
7.15 8.11 9.89 11.37 12.32 –
7.82 9.36 11.50 13.29 14.44 –
8.52 10.66 13.11 15.15 16.58 17.75
2 × 89 × 184
2 × 89 × 235
5.75
6.80
7.94
10.90 –
–
13.05 14.25 –
15.21 16.73 –
17.30 19.21 20.63
6.50 6.83 –
–
7.76 8.88 9.85 –
9.93 11.76 13.13 14.29
–
–
–
5.69
6.72
7.84
10.48 –
–
12.56 13.70 –
14.63 16.08 –
16.72 18.37 19.81
6.41 6.70 –
–
7.63 8.56 9.48 –
9.62 11.29 12.58 13.72
–
–
–
5.54
6.50
7.56
6.13 6.37 –
–
7.23 7.75 8.59 –
8.86 10.23 11.36 12.33
–
–
–
8.34 10.59 13.17 15.51 17.56 –
8.23 10.30 12.77 14.93 16.96 –
7.96 9.55 11.74 13.73 15.26 –
10.00 13.77 17.19 20.30 23.03 25.08 9.86 13.40 16.66 19.54 22.25 24.09 9.49 12.44 15.33 17.97 20.13 21.60
Interpolation is permitted for values between given loaded lengths.
– Indicates that a single trimmed joist of this cross section will not span the given loaded length. See Table 4.1.
34
Licensed copy: univulster, University of Ulster, 21/08/2017, Uncontrolled Copy, © TRADA Technology
4 Floor members
Table 4.12 Factored (design) reactions in kN at each end of double member
trimmer in Table 4.4 without an incoming partition
Dead loads
This table uses
regularised depth
gk = 0.25 kN/m , 0.50 kN/m , 1.25 kN/m
qk = 1.5 kN/m2 or Qk = 2.0 kN
2
2
2
Imposed load not exceeding
Strength Class C24
C24
Permanent (Dead) loads gk (kN/m2) excluding self-weight of joists
gk not more than 0.25
gk not more than 0.50
Trimmer size
Loaded length L (m) on Figure 4.3
2 × (mm × mm) 1.0
2.0
3.0
4.0
5.0
6.0
1.0
2.0
3.0
4.0
gk not more than 1.25
5.0
6.0
1.0
2.0
3.0
4.0
5.0
6.0
Factored (design) reactions in kN at each end of double member trimmer with an incoming partition
2 × 38 × 145
2 × 38 × 170
2 × 38 × 195
2 × 38 × 220
6.29 7.14 8.16 9.48 –
6.93 7.94 9.75 11.40 –
7.55 9.15 11.36 13.33 14.55
8.18 10.42 12.97 15.25 16.74
2 × 44 × 145
2 × 44 × 170
2 × 44 × 195
2 × 44 × 220
6.50 7.38 8.67 10.11 –
–
7.16 8.33 10.36 12.11 –
–
7.83 9.67 12.05 14.12 15.88 –
8.50 11.04 13.75 16.14 18.18 19.59
2 × 47 × 145
2 × 47 × 170
2 × 47 × 195
2 × 47 × 220
6.59 7.50 8.90 10.38 –
–
7.27 8.56 10.63 12.43 –
–
7.95 9.93 12.36 14.49 16.45 –
8.64 11.31 14.10 16.55 18.83 20.33
2 × 63 × 145
2 × 63 × 170
2 × 63 × 195
2 × 63 × 220
7.03 8.08 9.97
7.79 9.57 11.94
8.57 11.12 13.87
9.35 12.66 15.81
11.70 –
–
6.95 7.94 9.67
13.99 15.89 –
7.69 9.30 11.52
16.28 18.53 20.51 8.46 10.78 13.38
18.58 21.08 23.47 9.22 12.27 15.25
11.32 –
–
13.52 15.27 –
15.73 17.80 19.77
17.96 20.34 22.62
6.74 7.60 8.93
7.44 8.65 10.63
8.15 10.03 12.34
8.87 11.41 14.07
10.36 –
–
12.36 13.99 –
14.38 16.29 17.96
16.41 18.61 20.54
2 × 72 × 145
2 × 72 × 170
2 × 72 × 195
2 × 72 × 220
ALS/CLS
2 × 38 × 140
2 × 38 × 184
2 × 38 × 235
7.25 8.47 10.54 12.33 –
–
7.16 8.23 10.22
8.07 10.09 12.56 14.72 16.74 –
7.96 9.78 12.17
8.88 11.70 14.59 17.13 19.51 21.60 8.76 11.38 14.13
9.72 13.31 16.62 19.55 22.29 24.71 9.57 12.95 16.10
11.93 –
–
14.24 16.17 –
16.56 18.84 20.84
18.90 21.52 23.83
6.94 7.86 9.40
7.69 9.10 11.19
8.44 10.55 12.99
9.22 12.01 14.81
10.98 –
–
13.09 14.75 –
15.14 17.17 19.05
17.28 19.61 21.65
2 × 89 × 184
2 × 89 × 235
–
–
–
–
6.21 7.02 7.90 9.12
–
6.85 7.80 9.44 10.96 –
7.46 8.88 10.99 12.84 13.97
8.07 10.12 12.54 14.66 16.06
–
–
–
–
6.02
6.63
7.21
7.79
6.74 7.33 8.24 –
7.44 8.69 9.88 –
8.22 10.11 11.56 12.54
9.36 11.49 13.25 14.41
6.42 7.26 8.40 9.77 –
–
7.07 8.09 10.03 11.70 –
–
7.72 9.39 11.63 13.63 15.18 –
8.38 10.69 13.26 15.58 17.44 18.79
6.22
6.85
7.46
8.07
6.97 7.73 8.98 –
–
7.73 9.21 10.73 –
–
8.71 10.70 12.44 13.68 –
9.92 12.20 14.21 15.71 16.83
6.51 7.38 8.62 10.03 –
–
7.17 8.30 10.29 12.01 –
–
7.85 9.63 11.96 13.99 15.83 –
8.52 10.96 13.64 15.98 18.08 19.50
6.31 7.07 7.93 9.22 –
–
6.95 7.85 9.45 11.01 –
–
7.57 8.94 10.98 12.77 14.20 –
8.21 10.17 12.52 14.58 16.29 17.46
6.15 6.98 7.84 9.13 –
–
6.07 6.87 7.60 8.79 –
–
7.28 8.60 10.66 12.47 13.61 –
7.19 8.33 10.32 11.99 13.07 –
8.57 11.19 13.95 16.37 18.02 19.41 8.45 10.84 13.49 15.79 17.29 18.62
–
–
–
–
5.90 6.59 7.16 7.94
–
–
6.95 7.85 9.47 10.83 11.74
–
8.13 10.05 12.36 14.24 15.50 16.67
9.02 11.92 14.86 17.45 19.89 22.16 8.90 11.60 14.41 16.89 19.22 21.26 8.60 10.77 13.26 15.55 17.54 19.49
11.00 15.54 19.44 22.90 26.02 29.05 10.79 15.07 18.77 22.05 25.15 27.87 10.32 14.07 17.29 20.31 22.96 25.38
Interpolation is permitted for values between given loaded lengths.
– Indicates that a single trimmed joist of this cross section will not span the given loaded length. See Table 4.2.
35
Trimmed joist
d1
Double member trimmer
Clear span S
d3
Up to 3.0m maximum
Double member trimming joist
Void or stairwell
d2
Licensed copy: univulster, University of Ulster, 21/08/2017, Uncontrolled Copy, © TRADA Technology
Eurocode 5 span tables for solid timber members
Figure 4.4 Plan on double member trimming joist supporting double member trimmer
Notes to Trimming Joist Tables 4.13 to 4.18
The sizes of the double member trimming joists shown in Figure 4.4 will support loads from the following:
• The double member trimmer; and
• A lightweight non-loadbearing partition weighing not more than 1.0 kN/m run, supported on the double member
trimmer, and one supported on the double member trimming joist over its full length; and
• A variable (imposed) load not exceeding 1.5 kN/m2, or 2.0kN at the centre or end of the trimming joist.
It is assumed that the floor joists are of similar cross sectional dimensions for any of the trimmers presented in the tables.
Following the floor joist Tables 4.1 and 4.2, the dead load of the floor construction is taken as not exceeding 0.25 kN/m2,
0.50 kN/m2 and 1.25 kN/m2 respectively. See Section 4.1.4. These exclude the joist self-weights which are taken into
account in the span calculation. The two joists should be securely fixed together, see Section 4.2.5. No notching or drilling
of a trimming joist should be carried out unless proven by calculation, except as necessary to accommodate the flanges
of joist hangers.
Where necessary, the trimmed joists were assumed to be spaced at 400mm centres and the joists parallel to the trimming
joist to be spaced at 600mm centres. This imparts the maximum load on the trimming joist and may be conservative for
all other configurations.
36
Licensed copy: univulster, University of Ulster, 21/08/2017, Uncontrolled Copy, © TRADA Technology
4 Floor members
Table 4.13 Permissible clear spans of double member trimming joists which
support a trimmer and non-loadbearing lightweight partitions not exceeding
1.0 kN/m
Dead load
This table uses
regularised depth
gk = 0.25 kN/m2
Imposed load not exceeding
Strength Class C16
C16
qk = 1.5 kN/m2 or Qk = 2.0 kN
Service Class 1 or 2
Permanent (Dead) loads gk, excluding self-weights, not more than 0.25 kN/m2
See Figure 4.4 for positions of d1, d2, d3 and S
Trimming joist d1/d2 not more than 0.25
size
Dimension d3 (m)
2 × (mm × mm)
1.0
2.0
d1/d2 not more than 0.50
d1/d2 not more than 0.75
Dimension d3 (m)
3.0
Dimension d3 (m)
1.0
2.0
3.0
1.0
2.0
3.0
Clear span (m) S on Figure 4.4
2 × 38 × 145
2 × 38 × 170
2 × 38 × 195
2 × 38 × 220
2.12
2.57
3.03
3.49
2.01
2.46
2.89
3.31
1.85
2.26
2.68
3.09
1.98
2.40
2.82
3.24
1.62
2.00
2.39
2.79
1.37
1.72
2.09
2.45
2.02
2.44
2.86
3.29
1.67
2.06
2.45
2.85
1.44
1.79
2.15
2.52
2 × 44 × 145
2 × 44 × 170
2 × 44 × 195
2 × 44 × 220
2.26
2.74
3.22
3.70
2.15
2.62
3.06
3.51
1.98
2.41
2.85
3.28
2.11
2.56
3.00
3.44
1.74
2.15
2.56
2.98
1.49
1.86
2.25
2.64
2.15
2.59
3.04
3.48
1.80
2.21
2.62
3.04
1.55
1.93
2.31
2.70
2 × 47 × 145
2 × 47 × 170
2 × 47 × 195
2 × 47 × 220
2.33
2.82
3.31
3.80
2.22
2.69
3.15
3.60
2.04
2.48
2.93
3.37
2.18
2.63
3.08
3.53
1.80
2.22
2.64
3.07
1.54
1.93
2.32
2.72
2.21
2.66
3.12
3.57
1.85
2.27
2.70
3.12
1.61
1.99
2.39
2.79
2 × 63 × 145
2 × 63 × 170
2 × 63 × 195
2 × 63 × 220
2.63
3.17
3.71
4.25
2.51
3.02
3.52
4.02
2.32
2.81
3.30
3.79
2.46
2.96
3.45
3.95
2.07
2.53
3.00
3.47
1.80
2.22
2.66
3.11
2.49
2.99
3.49
3.99
2.12
2.59
3.05
3.53
1.86
2.29
2.73
3.17
2 × 72 × 145
2 × 72 × 170
2 × 72 × 195
2 × 72 × 220
ALS/CLS
2 × 38 × 140
2 × 38 × 184
2 × 38 × 235
2.78
3.34
3.91
4.47
2.65
3.18
3.70
4.22
2.45
2.96
3.47
3.98
2.59
3.11
3.63
4.15
2.20
2.68
3.17
3.66
1.92
2.37
2.83
3.29
2.63
3.15
3.67
4.19
2.25
2.74
3.23
3.72
1.98
2.43
2.89
3.36
2.03
2.83
3.77
1.92
2.70
3.57
1.77
2.49
3.34
1.90
2.64
3.50
1.55
2.22
3.03
1.31
1.93
2.68
1.94
2.68
3.54
1.60
2.28
3.09
1.37
1.99
2.74
2 × 89 × 184
2 × 89 × 235
3.96
5.16
3.75
4.88
3.52
4.63
3.68
4.81
3.22
4.29
2.88
3.90
3.72
4.85
3.28
4.35
2.95
3.97
Interpolation is permitted for values of d3 between 1.0m and 3.0m
37
Licensed copy: univulster, University of Ulster, 21/08/2017, Uncontrolled Copy, © TRADA Technology
Eurocode 5 span tables for solid timber members
Table 4.14 Permissible clear spans of double member trimming joists which
support a trimmer and non-loadbearing lightweight partitions not exceeding
1.0 kN/m
Dead load
This table uses
regularised depth
gk = 0.25 kN/m2
Imposed load not exceeding
Strength Class C24
C24
qk = 1.5 kN/m2 or Qk = 2.0 kN
Service Class 1 or 2
Permanent (Dead) loads gk, excluding self-weights, not more than 0.25 kN/m2
See Figure 4.4 for positions of d1, d2, d3 and S
Trimming joist d1/d2 not more than 0.25
size
Dimension d3 (m)
2 × (mm × mm)
1.0
2.0
d1/d2 not more than 0.50
d1/d2 not more than 0.75
Dimension d3 (m)
3.0
Dimension d3 (m)
1.0
2.0
3.0
1.0
2.0
3.0
Clear span (m) S on Figure 4.4
2 × 38 × 145
2 × 38 × 170
2 × 38 × 195
2 × 38 × 220
2.43
2.94
3.45
3.97
2.32
2.81
3.28
3.76
2.14
2.60
3.06
3.52
2.27
2.74
3.21
3.68
1.89
2.33
2.77
3.21
1.63
2.03
2.44
2.86
2.31
2.78
3.25
3.72
1.95
2.38
2.82
3.27
1.69
2.09
2.50
2.92
2 × 44 × 145
2 × 44 × 170
2 × 44 × 195
2 × 44 × 220
2.59
3.12
3.66
4.20
2.47
2.98
3.47
3.97
2.28
2.76
3.25
3.73
2.42
2.91
3.41
3.90
2.03
2.49
2.95
3.42
1.76
2.18
2.62
3.06
2.45
2.95
3.44
3.94
2.08
2.54
3.01
3.47
1.82
2.24
2.68
3.12
2 × 47 × 145
2 × 47 × 170
2 × 47 × 195
2 × 47 × 220
2.66
3.21
3.76
4.31
2.54
3.05
3.56
4.07
2.35
2.84
3.34
3.83
2.48
2.99
3.49
4.00
2.09
2.56
3.04
3.52
1.82
2.25
2.70
3.15
2.52
3.03
3.53
4.04
2.14
2.62
3.09
3.57
1.88
2.31
2.76
3.21
2 × 63 × 145
2 × 63 × 170
2 × 63 × 195
2 × 63 × 220
2.99
3.60
4.20
4.80
2.86
3.42
3.97
4.53
2.65
3.20
3.74
4.28
2.79
3.35
3.90
4.46
2.39
2.91
3.43
3.96
2.09
2.58
3.07
3.57
2.83
3.39
3.94
4.49
2.44
2.96
3.48
4.01
2.15
2.64
3.14
3.64
2 × 72 × 145
2 × 72 × 170
2 × 72 × 195
2 × 72 × 220
ALS/CLS
2 × 38 × 140
2 × 38 × 184
2 × 38 × 235
3.16
3.78
4.41
5.02
3.01
3.59
4.17
4.74
2.80
3.37
3.93
4.50
2.94
3.52
4.10
4.67
2.53
3.07
3.62
4.17
2.23
2.74
3.26
3.78
2.98
3.56
4.14
4.71
2.58
3.13
3.67
4.22
2.29
2.80
3.32
3.84
2.33
3.23
4.27
2.22
3.07
4.04
2.05
2.86
3.80
2.18
3.01
3.97
1.81
2.57
3.48
1.55
2.26
3.11
2.22
3.04
4.00
1.86
2.63
3.53
1.61
2.32
3.17
2 × 89 × 184
2 × 89 × 235
4.47
5.76
4.22
5.47
3.99
5.21
4.15
5.40
3.67
4.86
3.31
4.44
4.19
5.43
3.73
4.92
3.38
4.52
Interpolation is permitted for values of d3 between 1.0m and 3.0m
38
Licensed copy: univulster, University of Ulster, 21/08/2017, Uncontrolled Copy, © TRADA Technology
4 Floor members
Table 4.15 Permissible clear spans of double member trimming joists which
support a trimmer and non-loadbearing lightweight partitions not exceeding
1.0 kN/m
Dead load
This table uses
regularised depth
gk = 0.50 kN/m2
Imposed load not exceeding
Strength Class C16
C16
qk = 1.5 kN/m2 or Qk = 2.0 kN
Service Class 1 or 2
Permanent (Dead) loads gk, excluding self-weights, not more than 0.50 kN/m2
See Figure 4.4 for positions of d1, d2, d3 and S
Trimming joist d1/d2 not more than 0.25
size
Dimension d3 (m)
2 × (mm × mm)
1.0
2.0
d1/d2 not more than 0.50
d1/d2 not more than 0.75
Dimension d3 (m)
3.0
Dimension d3 (m)
1.0
2.0
3.0
1.0
2.0
3.0
Clear span (m) S on Figure 4.4
2 × 38 × 145
2 × 38 × 170
2 × 38 × 195
2 × 38 × 220
2.08
2.53
2.98
3.42
1.98
2.41
2.83
3.25
1.82
2.22
2.63
3.03
1.95
2.35
2.76
3.18
1.59
1.97
2.35
2.73
1.35
1.69
2.04
2.40
1.98
2.39
2.80
3.21
1.64
2.02
2.40
2.78
1.41
1.76
2.11
2.46
2 × 44 × 145
2 × 44 × 170
2 × 44 × 195
2 × 44 × 220
2.22
2.69
3.16
3.63
2.11
2.57
3.01
3.44
1.95
2.37
2.80
3.22
2.08
2.51
2.94
3.37
1.71
2.11
2.51
2.91
1.47
1.83
2.20
2.58
2.11
2.54
2.97
3.41
1.76
2.16
2.56
2.97
1.52
1.89
2.26
2.64
2 × 47 × 145
2 × 47 × 170
2 × 47 × 195
2 × 47 × 220
2.29
2.77
3.25
3.73
2.18
2.64
3.09
3.53
2.01
2.44
2.87
3.31
2.13
2.57
3.02
3.46
1.77
2.17
2.58
3.00
1.52
1.89
2.27
2.66
2.17
2.61
3.05
3.49
1.82
2.23
2.64
3.05
1.58
1.95
2.33
2.72
2 × 63 × 145
2 × 63 × 170
2 × 63 × 195
2 × 63 × 220
2.59
3.11
3.64
4.17
2.47
2.97
3.46
3.94
2.28
2.76
3.24
3.71
2.41
2.90
3.38
3.87
2.03
2.48
2.94
3.39
1.76
2.18
2.61
3.04
2.45
2.93
3.42
3.90
2.08
2.53
2.99
3.44
1.82
2.24
2.67
3.10
2 × 72 × 145
2 × 72 × 170
2 × 72 × 195
2 × 72 × 220
ALS/CLS
2 × 38 × 140
2 × 38 × 184
2 × 38 × 235
2.73
3.28
3.83
4.38
2.61
3.12
3.63
4.14
2.41
2.91
3.41
3.91
2.54
3.05
3.56
4.06
2.16
2.63
3.10
3.58
1.88
2.32
2.77
3.22
2.58
3.09
3.59
4.10
2.21
2.68
3.16
3.63
1.94
2.38
2.83
3.28
2.00
2.78
3.69
1.89
2.65
3.50
1.74
2.45
3.27
1.86
2.58
3.42
1.52
2.18
2.96
1.28
1.89
2.62
1.90
2.62
3.46
1.57
2.23
3.01
1.34
1.95
2.68
2 × 89 × 184
2 × 89 × 235
3.89
5.07
3.68
4.79
3.46
4.54
3.61
4.71
3.16
4.20
2.82
3.81
3.65
4.74
3.21
4.25
2.88
3.87
Interpolation is permitted for values of d3 between 1.0m and 3.0m
39
Licensed copy: univulster, University of Ulster, 21/08/2017, Uncontrolled Copy, © TRADA Technology
Eurocode 5 span tables for solid timber members
Table 4.16 Permissible clear spans of double member trimming joists which
support a trimmer and non-loadbearing lightweight partitions not exceeding
1.0 kN/m
Dead load
This table uses
regularised depth
gk = 0.50 kN/m2
Imposed load not exceeding
Strength Class C24
C24
qk = 1.5 kN/m2 or Qk = 2.0 kN
Service Class 1 or 2
Permanent (Dead) loads gk, excluding self-weights, not more than 0.50 kN/m2
See Figure 4.4 for positions of d1, d2, d3 and S
Trimming joist d1/d2 not more than 0.25
size
Dimension d3 (m)
2 × (mm × mm)
1.0
2.0
d1/d2 not more than 0.50
d1/d2 not more than 0.75
Dimension d3 (m)
3.0
Dimension d3 (m)
1.0
2.0
3.0
1.0
2.0
3.0
Clear span (m) S on Figure 4.4
2 × 38 × 145
2 × 38 × 170
2 × 38 × 195
2 × 38 × 220
2.39
2.89
3.39
3.89
2.28
2.76
3.22
3.68
2.10
2.55
3.00
3.45
2.23
2.69
3.15
3.61
1.86
2.28
2.71
3.14
1.60
1.99
2.39
2.79
2.26
2.72
3.18
3.64
1.91
2.33
2.76
3.19
1.66
2.05
2.45
2.85
2 × 44 × 145
2 × 44 × 170
2 × 44 × 195
2 × 44 × 220
2.54
3.07
3.59
4.12
2.43
2.92
3.41
3.89
2.24
2.71
3.19
3.66
2.37
2.85
3.34
3.82
1.99
2.44
2.89
3.34
1.73
2.14
2.56
2.99
2.41
2.89
3.37
3.85
2.04
2.49
2.94
3.39
1.78
2.20
2.62
3.04
2 × 47 × 145
2 × 47 × 170
2 × 47 × 195
2 × 47 × 220
2.61
3.15
3.69
4.22
2.50
3.00
3.49
3.99
2.31
2.79
3.27
3.76
2.44
2.93
3.42
3.91
2.05
2.51
2.97
3.44
1.79
2.21
2.64
3.08
2.47
2.96
3.46
3.95
2.10
2.56
3.02
3.48
1.84
2.27
2.70
3.13
2 × 63 × 145
2 × 63 × 170
2 × 63 × 195
2 × 63 × 220
2.94
3.53
4.12
4.71
2.81
3.35
3.90
4.44
2.60
3.14
3.67
4.20
2.74
3.28
3.82
4.36
2.34
2.85
3.36
3.87
2.06
2.53
3.01
3.49
2.77
3.32
3.86
4.40
2.39
2.90
3.41
3.92
2.11
2.59
3.07
3.55
2 × 72 × 145
2 × 72 × 170
2 × 72 × 195
2 × 72 × 220
ALS/CLS
2 × 38 × 140
2 × 38 × 184
2 × 38 × 235
3.10
3.71
4.33
4.93
2.95
3.52
4.09
4.65
2.75
3.30
3.86
4.41
2.89
3.45
4.02
4.58
2.48
3.01
3.54
4.07
2.19
2.68
3.18
3.69
2.92
3.49
4.05
4.61
2.53
3.06
3.59
4.12
2.24
2.74
3.24
3.75
2.29
3.17
4.19
2.18
3.01
3.96
2.01
2.80
3.72
2.14
2.95
3.88
1.78
2.52
3.40
1.53
2.21
3.04
2.17
2.98
3.92
1.82
2.57
3.45
1.58
2.27
3.09
2 × 89 × 184
2 × 89 × 235
4.38
5.65
4.14
5.36
3.91
5.11
4.07
5.29
3.59
4.75
3.24
4.34
4.10
5.32
3.64
4.80
3.30
4.40
Interpolation is permitted for values of d3 between 1.0m and 3.0m
40
Licensed copy: univulster, University of Ulster, 21/08/2017, Uncontrolled Copy, © TRADA Technology
4 Floor members
Table 4.17 Permissible clear spans of double member trimming joists which
support a trimmer and non-loadbearing lightweight partitions not exceeding
1.0 kN/m
Dead load
This table uses
regularised depth
gk = 1.25 kN/m2
Imposed load not exceeding
Strength Class C16
C16
qk = 1.5 kN/m2 or Qk = 2.0 kN
Service Class 1 or 2
Permanent (Dead) loads gk, excluding self-weights, not more than 1.25 kN/m2
See Figure 4.4 for positions of d1, d2, d3 and S
Trimming joist d1/d2 not more than 0.25
size
Dimension d3 (m)
2 × (mm × mm)
1.0
2.0
3.0
d1/d2 not more than 0.50
d1/d2 not more than 0.75
Dimension d3 (m)
Dimension d3 (m)
1.0
2.0
3.0
1.0
2.0
3.0
Clear span (m) S on Figure 4.4
2 × 38 × 145
2 × 38 × 170
2 × 38 × 195
2 × 38 × 220
1.99
2.41
2.83
3.25
1.88
2.29
2.69
3.08
1.74
2.12
2.49
2.87
1.85
2.23
2.62
3.00
1.52
1.87
2.22
2.57
1.29
1.61
1.93
2.26
1.88
2.26
2.65
3.03
1.56
1.91
2.26
2.62
1.34
1.66
1.98
2.31
2 × 44 × 145
2 × 44 × 170
2 × 44 × 195
2 × 44 × 220
2.12
2.56
3.01
3.45
2.01
2.44
2.86
3.27
1.86
2.26
2.66
3.05
1.97
2.37
2.78
3.18
1.63
2.00
2.37
2.75
1.40
1.74
2.08
2.43
2.00
2.40
2.81
3.21
1.67
2.04
2.42
2.79
1.45
1.79
2.13
2.48
2 × 47 × 145
2 × 47 × 170
2 × 47 × 195
2 × 47 × 220
2.18
2.63
3.09
3.54
2.07
2.51
2.93
3.35
1.92
2.32
2.73
3.14
2.03
2.44
2.85
3.27
1.69
2.06
2.44
2.83
1.45
1.80
2.15
2.51
2.06
2.47
2.88
3.30
1.73
2.11
2.49
2.87
1.50
1.85
2.20
2.55
2 × 63 × 145
2 × 63 × 170
2 × 63 × 195
2 × 63 × 220
2.47
2.97
3.46
3.96
2.35
2.82
3.28
3.75
2.18
2.63
3.07
3.52
2.29
2.75
3.20
3.66
1.93
2.35
2.77
3.20
1.68
2.07
2.46
2.86
2.32
2.78
3.23
3.68
1.97
2.39
2.82
3.24
1.73
2.12
2.51
2.91
2 × 72 × 145
2 × 72 × 170
2 × 72 × 195
2 × 72 × 220
ALS/CLS
2 × 38 × 140
2 × 38 × 184
2 × 38 × 235
2.61
3.12
3.64
4.16
2.48
2.97
3.45
3.93
2.30
2.77
3.24
3.71
2.42
2.89
3.37
3.84
2.05
2.49
2.93
3.38
1.79
2.20
2.62
3.03
2.45
2.92
3.40
3.87
2.09
2.53
2.97
3.42
1.84
2.25
2.66
3.08
1.91
2.64
3.50
1.80
2.52
3.32
1.67
2.33
3.10
1.77
2.45
3.23
1.45
2.06
2.79
1.23
1.79
2.46
1.80
2.48
3.26
1.49
2.11
2.83
1.28
1.84
2.51
2 × 89 × 184
2 × 89 × 235
3.70
4.83
3.50
4.55
3.29
4.31
3.42
4.45
2.99
3.95
2.67
3.58
3.45
4.48
3.03
3.99
2.72
3.63
Interpolation is permitted for values of d3 between 1.0m and 3.0m
41
Licensed copy: univulster, University of Ulster, 21/08/2017, Uncontrolled Copy, © TRADA Technology
Eurocode 5 span tables for solid timber members
Table 4.18 Permissible clear spans of double member trimming joists which
support a trimmer and non-loadbearing lightweight partitions not exceeding
1.0 kN/m
Dead load
This table uses
regularised depth
gk = 1.25 kN/m2
Imposed load not exceeding
Strength Class C24
C24
qk = 1.5 kN/m2 or Qk = 2.0 kN
Service Class 1 or 2
Permanent (Dead) loads gk, excluding self-weights, not more than 1.25 kN/m2
See Figure 4.4 for positions of d1, d2, d3 and S
Trimming joist d1/d2 not more than 0.25
size
Dimension d3 (m)
2 × (mm × mm)
1.0
2.0
d1/d2 not more than 0.50
d1/d2 not more than 0.75
Dimension d3 (m)
3.0
Dimension d3 (m)
1.0
2.0
3.0
1.0
2.0
3.0
Clear span (m) S on Figure 4.4
2 × 38 × 145
2 × 38 × 170
2 × 38 × 195
2 × 38 × 220
2.28
2.75
3.22
3.69
2.17
2.62
3.06
3.49
2.01
2.43
2.85
3.27
2.12
2.55
2.98
3.41
1.77
2.16
2.56
2.96
1.53
1.89
2.26
2.63
2.15
2.57
3.00
3.43
1.81
2.20
2.60
3.00
1.57
1.94
2.30
2.67
2 × 44 × 145
2 × 44 × 170
2 × 44 × 195
2 × 44 × 220
2.43
2.92
3.41
3.91
2.31
2.78
3.24
3.69
2.14
2.58
3.03
3.47
2.25
2.70
3.15
3.61
1.89
2.31
2.73
3.15
1.65
2.03
2.42
2.81
2.28
2.73
3.18
3.63
1.93
2.35
2.77
3.18
1.69
2.07
2.46
2.85
2 × 47 × 145
2 × 47 × 170
2 × 47 × 195
2 × 47 × 220
2.49
3.00
3.50
4.01
2.37
2.85
3.32
3.79
2.20
2.65
3.11
3.56
2.31
2.78
3.24
3.70
1.95
2.38
2.81
3.24
1.70
2.09
2.49
2.90
2.34
2.80
3.26
3.72
1.99
2.42
2.84
3.27
1.75
2.14
2.54
2.94
2 × 63 × 145
2 × 63 × 170
2 × 63 × 195
2 × 63 × 220
2.81
3.36
3.92
4.47
2.67
3.19
3.70
4.22
2.48
2.98
3.48
3.98
2.60
3.11
3.62
4.12
2.22
2.69
3.17
3.64
1.96
2.39
2.84
3.28
2.63
3.14
3.64
4.15
2.26
2.73
3.21
3.68
2.00
2.44
2.88
3.33
2 × 72 × 145
2 × 72 × 170
2 × 72 × 195
2 × 72 × 220
ALS/CLS
2 × 38 × 140
2 × 38 × 184
2 × 38 × 235
2.96
3.53
4.11
4.69
2.81
3.35
3.89
4.42
2.62
3.14
3.66
4.18
2.74
3.27
3.80
4.33
2.35
2.85
3.34
3.83
2.08
2.54
3.00
3.47
2.77
3.30
3.83
4.35
2.39
2.88
3.38
3.87
2.12
2.58
3.05
3.51
2.19
3.01
3.97
2.08
2.86
3.75
1.92
2.66
3.53
2.03
2.79
3.66
1.69
2.38
3.20
1.46
2.10
2.86
2.06
2.82
3.69
1.73
2.42
3.23
1.50
2.14
2.90
2 × 89 × 184
2 × 89 × 235
4.17
5.39
3.94
5.10
3.72
4.85
3.85
5.00
3.39
4.47
3.06
4.07
3.88
5.02
3.43
4.51
3.10
4.12
Interpolation is permitted for values of d3 between 1.0m and 3.0m
42
Licensed copy: univulster, University of Ulster, 21/08/2017, Uncontrolled Copy, © TRADA Technology
4 Floor members
Table 4.19 Nail centres for double member trimming joists in Table 4.13
Dead loads
This table uses
regularised depth
gk = 0.25 kN/m2
Imposed load not exceeding
qk = 1.5 kN/m
2
or
Qk = 2.0 kN
Strength Class C16
C16
Permanent (Dead) loads gk, excluding self-weights, not more than 0.25 kN/m2
See Figure 4.4 for positions of d1, d2, d3 and S
Trimming joist d1/d2 not more than 0.25
size
Dimension d3 (m)
2 × (mm × mm)
1.0
2.0
d1/d2 not more than 0.50
d1/d2 not more than 0.75
Dimension d3 (m)
3.0
Dimension d3 (m)
1.0
2.0
3.0
1.0
2.0
3.0
Nail centres S (mm) on Figure 4.2
2 × 38 × 145
2 × 38 × 170
2 × 38 × 195
2 × 38 × 220
350
360
430
430
330
400
410
470
300
370
380
440
330
400
400
460
320
330
390
390
270
280
340
400
330
400
400
460
270
340
400
400
280
290
350
360
2 × 44 × 145
2 × 44 × 170
2 × 44 × 195
2 × 44 × 220
370
450
530
520
430
430
510
500
390
400
470
460
420
420
490
490
340
420
420
490
290
370
370
430
430
430
500
490
350
360
430
500
310
380
380
450
2 × 47 × 145
2 × 47 × 170
2 × 47 × 195
2 × 47 × 220
380
460
470
540
360
440
440
510
400
410
480
480
360
430
510
500
360
360
430
510
300
380
380
450
360
440
510
510
370
370
440
440
320
390
390
460
2 × 63 × 145
2 × 63 × 170
2 × 63 × 195
2 × 63 × 220
650
630
740
700
620
600
700
800
580
560
650
750
610
590
690
790
510
630
590
690
440
550
530
620
620
590
690
790
530
640
610
700
460
570
540
630
2 × 72 × 145
2 × 72 × 170
2 × 72 × 195
2 × 72 × 220
ALS/CLS
2 × 38 × 140
2 × 38 × 184
2 × 38 × 235
550
660
650
630
530
630
730
700
490
590
690
660
510
620
720
690
540
530
630
730
470
590
560
650
520
630
730
690
560
540
640
740
490
480
570
670
330
400
470
320
380
440
290
410
470
310
370
430
300
370
430
260
320
380
320
380
440
310
380
440
270
330
390
2 × 89 × 184
2 × 89 × 235
560
570
530
540
580
570
520
530
530
610
480
550
530
530
540
620
490
560
For interpolated values from Table 4.13, use the lower spacing from the two corresponding spacings in this table.
Nail specifications used; for 38mm wide sections: 3.75mm diameter x 75mm long, for 44mm & 47mm wide sections:
4.00mm diameter x 90mm long and for 63mm, 72mm & 89mm wide sections: 5.00mm diameter x 125mm long.
Each trimming joist should be fixed in line with a minimum of two nails at 1/3 span positions.
43
Licensed copy: univulster, University of Ulster, 21/08/2017, Uncontrolled Copy, © TRADA Technology
Eurocode 5 span tables for solid timber members
Table 4.20 Nail centres for double member trimming joists in Table 4.14
Dead loads
This table uses
regularised depth
gk = 0.25 kN/m2
Imposed load not exceeding
qk = 1.5 kN/m
2
or
Qk = 2.0 kN
Strength Class C24
C24
Permanent (Dead) loads gk, excluding self-weights, not more than 0.25 kN/m2
See Figure 4.4 for positions of d1, d2, d3 and S
Trimming joist d1/d2 not more than 0.25
size
Dimension d3 (m)
2 × (mm × mm)
1.0
2.0
d1/d2 not more than 0.50
d1/d2 not more than 0.75
Dimension d3 (m)
3.0
Dimension d3 (m)
1.0
2.0
3.0
1.0
2.0
3.0
Nail centres S (mm) on Figure 4.2
2 × 38 × 145
2 × 38 × 170
2 × 38 × 195
2 × 38 × 220
400
420
490
490
380
460
460
530
350
430
430
500
370
450
450
520
370
380
460
450
320
330
400
400
380
460
460
530
320
390
470
460
330
340
410
410
2 × 44 × 145
2 × 44 × 170
2 × 44 × 195
2 × 44 × 220
430
520
520
590
490
490
570
560
450
460
540
530
480
480
560
550
400
490
490
560
350
430
430
500
490
490
570
560
410
420
500
570
360
440
440
520
2 × 47 × 145
2 × 47 × 170
2 × 47 × 195
2 × 47 × 220
440
530
530
610
420
500
500
580
460
470
550
540
410
490
490
570
410
420
500
500
360
450
440
520
420
500
500
570
420
430
510
500
370
460
460
530
2 × 63 × 145
2 × 63 × 170
2 × 63 × 195
2 × 63 × 220
740
710
830
800
710
680
790
750
660
630
740
850
690
660
780
740
590
720
680
790
520
640
610
710
700
670
780
740
600
730
690
800
530
660
620
720
2 × 72 × 145
2 × 72 × 170
2 × 72 × 195
2 × 72 × 220
ALS/CLS
2 × 38 × 140
2 × 38 × 184
2 × 38 × 235
630
750
730
710
600
710
830
670
550
670
780
740
580
700
820
770
630
610
720
690
550
540
650
750
590
710
820
670
640
620
730
700
570
560
660
760
380
460
530
370
430
500
340
400
470
360
420
490
360
420
490
310
370
440
360
430
500
370
430
500
320
380
450
2 × 89 × 184
2 × 89 × 235
630
630
600
600
660
570
590
590
610
600
550
550
590
600
620
610
560
560
For interpolated values from Table 4.14, use the lower spacing from the two corresponding spacings in this table.
Nail specifications used; for 38mm wide sections: 3.75mm diameter x 75mm long, for 44mm & 47mm wide sections:
4.00mm diameter x 90mm long and for 63mm, 72mm & 89mm wide sections: 5.00mm diameter x 125mm long.
Each trimming joist should be fixed in line with a minimum of two nails at 1/3 span positions.
44
Licensed copy: univulster, University of Ulster, 21/08/2017, Uncontrolled Copy, © TRADA Technology
4 Floor members
Table 4.21 Nail centres for double member trimming joists in Table 4.15
Dead loads
This table uses
regularised depth
gk = 0.50 kN/m2
Imposed load not exceeding
qk = 1.5 kN/m
2
or
Qk = 2.0 kN
Strength Class C16
C16
Permanent (Dead) loads gk, excluding self-weights, not more than 0.50 kN/m2
See Figure 4.4 for positions of d1, d2, d3 and S
Trimming joist d1/d2 not more than 0.25
size
Dimension d3 (m)
2 × (mm × mm)
1.0
2.0
d1/d2 not more than 0.50
d1/d2 not more than 0.75
Dimension d3 (m)
3.0
Dimension d3 (m)
1.0
2.0
3.0
1.0
2.0
3.0
Nail centres S (mm) on Figure 4.2
2 × 38 × 145
2 × 38 × 170
2 × 38 × 195
2 × 38 × 220
340
360
420
420
320
340
400
400
300
370
370
430
320
390
390
450
260
320
390
380
270
280
340
340
330
390
400
450
270
330
340
390
280
290
350
350
2 × 44 × 145
2 × 44 × 170
2 × 44 × 195
2 × 44 × 220
370
440
450
510
350
420
500
490
390
390
460
460
410
410
480
480
340
350
410
480
290
360
360
420
350
420
490
480
350
360
420
490
300
370
370
430
2 × 47 × 145
2 × 47 × 170
2 × 47 × 195
2 × 47 × 220
380
460
460
530
360
440
440
500
330
400
470
470
350
420
430
490
350
360
430
420
300
370
370
440
360
430
430
490
360
370
430
430
310
390
380
450
2 × 63 × 145
2 × 63 × 170
2 × 63 × 195
2 × 63 × 220
510
620
720
690
610
590
690
650
570
550
640
740
600
570
670
640
500
620
580
670
440
540
520
600
610
580
680
650
510
500
590
680
450
560
530
610
2 × 72 × 145
2 × 72 × 170
2 × 72 × 195
2 × 72 × 220
ALS/CLS
2 × 38 × 140
2 × 38 × 184
2 × 38 × 235
540
650
630
730
520
620
600
690
480
580
680
650
500
610
710
670
530
520
620
590
470
460
550
640
510
610
710
680
550
530
630
600
480
470
560
650
330
390
460
310
370
430
290
340
400
310
360
420
300
360
420
250
310
370
310
370
430
260
370
430
260
320
380
2 × 89 × 184
2 × 89 × 235
550
560
520
530
490
500
510
520
520
590
470
540
520
520
530
600
480
550
For interpolated values from Table 4.15, use the lower spacing from the two corresponding spacings in this table.
Nail specifications used; for 38mm wide sections: 3.75mm diameter x 75mm long, for 44mm & 47mm wide sections:
4.00mm diameter x 90mm long and for 63mm, 72mm & 89mm wide sections: 5.00mm diameter x 125mm long.
Each trimming joist should be fixed in line with a minimum of two nails at 1/3 span positions.
45
Licensed copy: univulster, University of Ulster, 21/08/2017, Uncontrolled Copy, © TRADA Technology
Eurocode 5 span tables for solid timber members
Table 4.22 Nail centres for double member trimming joists in Table 4.16
Dead loads
This table uses
regularised depth
gk = 0.50 kN/m2
Imposed load not exceeding
qk = 1.5 kN/m
2
or
Qk = 2.0 kN
Strength Class C24
C24
Permanent (Dead) loads gk, excluding self-weights, not more than 0.50 kN/m2
See Figure 4.4 for positions of d1, d2, d3 and S
Trimming joist d1/d2 not more than 0.25
size
Dimension d3 (m)
2 × (mm × mm)
1.0
2.0
d1/d2 not more than 0.50
d1/d2 not more than 0.75
Dimension d3 (m)
3.0
Dimension d3 (m)
1.0
2.0
3.0
1.0
2.0
3.0
Nail centres S (mm) on Figure 4.2
2 × 38 × 145
2 × 38 × 170
2 × 38 × 195
2 × 38 × 220
390
410
480
480
370
390
450
460
350
420
420
490
370
440
440
450
300
380
380
440
320
330
390
390
370
380
450
450
310
380
390
450
330
340
400
400
2 × 44 × 145
2 × 44 × 170
2 × 44 × 195
2 × 44 × 220
420
510
510
580
400
480
480
550
440
450
530
520
470
470
550
540
390
400
480
550
340
420
420
490
400
480
560
550
400
410
480
480
350
430
430
500
2 × 47 × 145
2 × 47 × 170
2 × 47 × 195
2 × 47 × 220
430
520
520
600
410
490
490
570
380
460
460
530
400
480
480
550
410
410
490
490
350
440
440
510
410
490
490
560
420
420
500
490
360
370
440
520
2 × 63 × 145
2 × 63 × 170
2 × 63 × 195
2 × 63 × 220
580
700
820
780
700
670
770
740
650
620
730
840
680
650
760
720
580
560
670
770
510
630
600
690
690
660
770
730
590
570
680
780
520
640
610
710
2 × 72 × 145
2 × 72 × 170
2 × 72 × 195
2 × 72 × 220
ALS/CLS
2 × 38 × 140
2 × 38 × 184
2 × 38 × 235
620
740
720
700
590
700
680
660
540
660
770
730
570
690
660
650
610
600
700
670
540
530
630
730
580
690
670
650
630
610
710
680
560
540
640
740
380
450
520
360
430
490
330
400
460
350
420
480
350
420
480
300
360
430
360
420
480
300
420
490
310
370
440
2 × 89 × 184
2 × 89 × 235
620
560
590
590
550
560
580
580
590
590
530
610
580
590
600
600
540
550
For interpolated values from Table 4.16, use the lower spacing from the two corresponding spacings in this table.
Nail specifications used; for 38mm wide sections: 3.75mm diameter x 75mm long, for 44mm & 47mm wide sections:
4.00mm diameter x 90mm long and for 63mm, 72mm & 89mm wide sections: 5.00mm diameter x 125mm long.
Each trimming joist should be fixed in line with a minimum of two nails at 1/3 span positions.
46
Licensed copy: univulster, University of Ulster, 21/08/2017, Uncontrolled Copy, © TRADA Technology
4 Floor members
Table 4.23 Nail centres for double member trimming joists in Table 4.17
Dead loads
This table uses
regularised depth
gk = 1.25 kN/m2
Imposed load not exceeding
qk = 1.5 kN/m
2
or
Qk = 2.0 kN
Strength Class C16
C16
Permanent (Dead) loads gk, excluding self-weights, not more than 1.25 kN/m2
See Figure 4.4 for positions of d1, d2, d3 and S
Trimming joist d1/d2 not more than 0.25
size
Dimension d3 (m)
2 × (mm × mm)
1.0
2.0
d1/d2 not more than 0.50
d1/d2 not more than 0.75
Dimension d3 (m)
3.0
Dimension d3 (m)
1.0
2.0
3.0
1.0
2.0
3.0
Nail centres S (mm) on Figure 4.2
2 × 38 × 145
2 × 38 × 170
2 × 38 × 195
2 × 38 × 220
330
340
350
400
310
320
380
380
290
300
350
350
300
310
370
370
250
310
310
360
250
260
320
320
310
320
370
370
250
310
320
370
220
270
280
330
2 × 44 × 145
2 × 44 × 170
2 × 44 × 195
2 × 44 × 220
350
420
420
430
330
400
400
460
310
370
370
430
320
390
390
450
320
330
390
390
280
280
340
400
330
400
400
450
330
340
400
390
280
290
350
410
2 × 47 × 145
2 × 47 × 170
2 × 47 × 195
2 × 47 × 220
360
370
440
440
340
350
410
410
310
380
380
440
330
400
400
400
280
340
400
400
290
290
350
350
340
410
410
410
280
350
350
400
290
300
360
360
2 × 63 × 145
2 × 63 × 170
2 × 63 × 195
2 × 63 × 220
490
590
570
660
460
560
650
620
430
520
610
580
450
540
640
600
480
470
550
630
420
510
490
570
460
550
640
610
490
470
560
640
430
420
500
580
2 × 72 × 145
2 × 72 × 170
2 × 72 × 195
2 × 72 × 220
ALS/CLS
2 × 38 × 140
2 × 38 × 184
2 × 38 × 235
520
520
600
590
490
590
570
650
460
550
530
610
480
570
560
640
410
490
580
560
440
440
520
500
480
580
560
640
410
500
590
560
460
440
530
510
310
370
380
300
350
410
270
330
380
290
340
400
240
290
340
240
290
350
300
350
400
240
300
350
250
300
350
2 × 89 × 184
2 × 89 × 235
520
480
500
500
470
530
480
490
420
490
440
510
490
490
430
490
450
510
For interpolated values from Table 4.17, use the lower spacing from the two corresponding spacings in this table.
Nail specifications used; for 38mm wide sections: 3.75mm diameter x 75mm long, for 44mm & 47mm wide sections:
4.00mm diameter x 90mm long and for 63mm, 72mm & 89mm wide sections: 5.00mm diameter x 125mm long.
Each trimming joist should be fixed in line with a minimum of two nails at 1/3 span positions.
47
Licensed copy: univulster, University of Ulster, 21/08/2017, Uncontrolled Copy, © TRADA Technology
Eurocode 5 span tables for solid timber members
Table 4.24 Nail centres for double member trimming joists in Table 4.18
Dead loads
This table uses
regularised depth
gk = 1.25 kN/m2
Imposed load not exceeding
qk = 1.5 kN/m
2
or
Qk = 2.0 kN
Strength Class C24
C24
Permanent (Dead) loads gk, excluding self-weights, not more than 1.25 kN/m2
See Figure 4.4 for positions of d1, d2, d3 and S
Trimming joist d1/d2 not more than 0.25
size
Dimension d3 (m)
2 × (mm × mm)
1.0
2.0
d1/d2 not more than 0.50
d1/d2 not more than 0.75
Dimension d3 (m)
3.0
Dimension d3 (m)
1.0
2.0
3.0
1.0
2.0
3.0
Nail centres S (mm) on Figure 4.2
2 × 38 × 145
2 × 38 × 170
2 × 38 × 195
2 × 38 × 220
320
390
400
460
360
370
380
430
330
340
400
400
350
360
420
420
290
360
360
420
250
310
320
370
350
360
370
420
300
360
370
370
260
320
320
380
2 × 44 × 145
2 × 44 × 170
2 × 44 × 195
2 × 44 × 220
400
410
480
480
380
460
460
520
350
430
430
490
370
450
450
510
370
380
450
440
320
330
400
460
370
450
450
510
380
390
460
450
330
340
410
400
2 × 47 × 145
2 × 47 × 170
2 × 47 × 195
2 × 47 × 220
410
420
500
500
390
400
470
470
360
440
440
500
380
390
460
460
320
390
400
460
340
340
410
410
390
400
460
460
330
400
400
460
340
350
420
410
2 × 63 × 145
2 × 63 × 170
2 × 63 × 195
2 × 63 × 220
560
670
650
630
530
630
610
700
490
590
690
660
520
620
720
680
550
530
630
600
480
470
560
650
520
620
720
690
560
540
640
610
500
480
570
660
2 × 72 × 145
2 × 72 × 170
2 × 72 × 195
2 × 72 × 220
ALS/CLS
2 × 38 × 140
2 × 38 × 184
2 × 38 × 235
590
580
680
660
560
670
640
630
520
620
610
690
540
650
630
720
470
560
660
630
510
500
600
570
550
650
630
720
470
570
560
640
530
510
600
580
360
430
440
340
400
410
320
380
440
330
390
450
280
340
390
290
340
400
340
400
460
280
340
400
250
350
410
2 × 89 × 184
2 × 89 × 235
590
530
560
500
530
530
550
550
480
490
500
580
550
500
490
500
510
580
For interpolated values from Table 4.18, use the lower spacing from the two corresponding spacings in this table.
Nail specifications used; for 38mm wide sections: 3.75mm diameter x 75mm long, for 44mm & 47mm wide sections:
4.00mm diameter x 90mm long and for 63mm, 72mm & 89mm wide sections: 5.00mm diameter x 125mm long.
Each trimming joist should be fixed in line with a minimum of two nails at 1/3 span positions.
48
Licensed copy: univulster, University of Ulster, 21/08/2017, Uncontrolled Copy, © TRADA Technology
4 Floor members
Table 4.25 Bolt centres for double member trimming joists in Table 4.13
Dead loads
This table uses
regularised depth
gk = 0.25 kN/m2
Imposed load not exceeding
qk = 1.5 kN/m
2
or
Qk = 2.0 kN
Strength Class C16
C16
Permanent (Dead) loads gk, excluding self-weights, not more than 0.25 kN/m2
See Figure 4.4 for positions of d1, d2, d3 and S
Trimming joist d1/d2 not more than 0.25
size
Dimension d3 (m)
2 × (mm × mm)
1.0
2.0
d1/d2 not more than 0.50
d1/d2 not more than 0.75
Dimension d3 (m)
3.0
Dimension d3 (m)
1.0
2.0
3.0
1.0
2.0
3.0
Bolt centres S (mm) on Figure 4.2
2 × 38 × 145
2 × 38 × 170
2 × 38 × 195
2 × 38 × 220
700
850
1010
1160
670
810
960
1100
610
750
890
1020
660
800
940
1080
540
660
790
920
450
570
690
810
670
810
950
1090
550
680
810
940
470
590
710
840
2 × 44 × 145
2 × 44 × 170
2 × 44 × 195
2 × 44 × 220
750
910
1070
1200
710
870
1020
1170
660
800
940
1090
700
850
990
1140
580
710
850
990
740
620
740
870
710
860
1010
1160
590
730
870
1010
770
640
770
900
2 × 47 × 145
2 × 47 × 170
2 × 47 × 195
2 × 47 × 220
770
930
1100
1200
730
890
1040
1200
680
820
970
1120
720
870
1020
1170
900
730
870
1020
770
640
770
900
730
880
1030
1190
920
750
890
1040
800
660
790
920
2 × 63 × 145
2 × 63 × 170
2 × 63 × 195
2 × 63 × 220
1200
1050
1200
1200
1200
1200
1170
1200
1160
1200
1090
1200
1200
1200
1150
1200
1030
1200
1200
1150
890
1110
1200
1030
1200
1200
1160
1200
1060
1200
1200
1170
920
1140
1200
1050
2 × 72 × 145
2 × 72 × 170
2 × 72 × 195
2 × 72 × 220
ALS/CLS
2 × 38 × 140
2 × 38 × 184
2 × 38 × 235
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1090
1200
1200
1200
950
1180
1200
1200
1200
1200
1200
1200
1120
1200
1200
1200
980
1200
1200
1200
670
940
1200
640
900
1180
590
830
1110
630
870
1160
510
740
1000
430
640
890
640
890
1170
530
760
1020
450
660
910
2 × 89 × 184
2 × 89 × 235
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
For interpolated values from Table 4.13, use the lower spacing from the two corresponding spacings in this table.
Bolt specifications used; for 38mm, 44mm, 47mm & 63mm wide sections: M12 bolts (min. 3mm x 38mm M12 washers under head & nut),
for 72mm & 89mm wide sections: M16 bolts (min. 4mm x 48mm M16 washers under head & nut).
Each trimming joist should be fixed in line with a minimum of two bolts at 1/3 span positions.
49
Licensed copy: univulster, University of Ulster, 21/08/2017, Uncontrolled Copy, © TRADA Technology
Eurocode 5 span tables for solid timber members
Table 4.26 Bolt centres for double member trimming joists in Table 4.14
Dead loads
This table uses
regularised depth
gk = 0.25 kN/m2
Imposed load not exceeding
qk = 1.5 kN/m
2
or
Qk = 2.0 kN
Strength Class C24
C24
Permanent (Dead) loads gk, excluding self-weights, not more than 0.25 kN/m2
See Figure 4.4 for positions of d1, d2, d3 and S
Trimming joist d1/d2 not more than 0.25
size
Dimension d3 (m)
2 × (mm × mm)
1.0
2.0
d1/d2 not more than 0.50
d1/d2 not more than 0.75
Dimension d3 (m)
3.0
Dimension d3 (m)
1.0
2.0
3.0
1.0
2.0
3.0
Bolt centres S (mm) on Figure 4.2
2 × 38 × 145
2 × 38 × 170
2 × 38 × 195
2 × 38 × 220
810
980
1150
1200
770
930
1090
1200
710
860
1020
1170
750
910
1070
1200
630
770
920
1070
540
670
810
950
760
920
1080
1200
640
790
940
1080
560
690
830
970
2 × 44 × 145
2 × 44 × 170
2 × 44 × 195
2 × 44 × 220
860
1040
1200
1200
820
990
1150
1200
760
920
1080
1200
800
970
1130
1200
1010
820
980
1130
870
720
870
1010
810
980
1140
1200
1040
840
1000
1150
900
740
890
1040
2 × 47 × 145
2 × 47 × 170
2 × 47 × 195
2 × 47 × 220
880
1060
1200
1200
840
1010
1180
1200
1170
940
1110
1200
820
990
1160
1200
1040
850
1010
1170
900
1120
890
1040
840
1000
1170
1200
1070
870
1030
1180
930
1150
920
1070
2 × 63 × 145
2 × 63 × 170
2 × 63 × 195
2 × 63 × 220
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1190
1200
1200
1200
1040
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1070
1200
1200
1200
2 × 72 × 145
2 × 72 × 170
2 × 72 × 195
2 × 72 × 220
ALS/CLS
2 × 38 × 140
2 × 38 × 184
2 × 38 × 235
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1110
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1140
1200
1200
1200
770
1070
1200
740
1020
1200
680
950
1200
720
1000
1200
600
850
1160
510
750
1030
730
1010
1200
610
870
1170
530
770
1050
2 × 89 × 184
2 × 89 × 235
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
For interpolated values from Table 4.14, use the lower spacing from the two corresponding spacings in this table.
Bolt specifications used; for 38mm, 44mm, 47mm & 63mm wide sections: M12 bolts (min. 3mm x 38mm M12 washers under head & nut),
for 72mm & 89mm wide sections: M16 bolts (min. 4mm x 48mm M16 washers under head & nut).
Each trimming joist should be fixed in line with a minimum of two bolts at 1/3 span positions.
50
Licensed copy: univulster, University of Ulster, 21/08/2017, Uncontrolled Copy, © TRADA Technology
4 Floor members
Table 4.27 Bolt centres for double member trimming joists in Table 4.15
Dead loads
This table uses
regularised depth
gk = 0.50 kN/m2
Imposed load not exceeding
qk = 1.5 kN/m
2
or
Qk = 2.0 kN
Strength Class C16
C16
Permanent (Dead) loads gk, excluding self-weights, not more than 0.50 kN/m2
See Figure 4.4 for positions of d1, d2, d3 and S
Trimming joist d1/d2 not more than 0.25
size
Dimension d3 (m)
2 × (mm × mm)
1.0
2.0
3.0
d1/d2 not more than 0.50
d1/d2 not more than 0.75
Dimension d3 (m)
Dimension d3 (m)
1.0
2.0
3.0
1.0
2.0
3.0
Bolt centres S (mm) on Figure 4.2
2 × 38 × 145
2 × 38 × 170
2 × 38 × 195
2 × 38 × 220
690
840
990
1140
650
800
940
1080
600
740
870
1000
640
780
920
1050
530
650
780
900
450
560
680
800
660
790
930
1070
540
670
800
920
460
580
700
820
2 × 44 × 145
2 × 44 × 170
2 × 44 × 195
2 × 44 × 220
740
890
1050
1200
700
850
1000
1140
650
790
930
1070
690
830
970
1120
570
700
830
970
730
600
730
850
700
840
990
1130
580
720
850
980
500
620
750
870
2 × 47 × 145
2 × 47 × 170
2 × 47 × 195
2 × 47 × 220
760
920
1080
1200
720
880
1020
1170
660
810
950
1100
710
850
1000
1150
580
720
860
990
750
630
750
880
720
870
1010
1160
600
740
870
1010
780
650
770
900
2 × 63 × 145
2 × 63 × 170
2 × 63 × 195
2 × 63 × 220
1200
1030
1200
1200
1200
980
1150
1200
1140
1200
1070
1200
1200
1200
1120
1200
1010
1200
970
1130
880
1090
1200
1010
1200
1200
1130
1200
1030
1200
990
1140
910
1120
1200
1030
2 × 72 × 145
2 × 72 × 170
2 × 72 × 195
2 × 72 × 220
ALS/CLS
2 × 38 × 140
2 × 38 × 184
2 × 38 × 235
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1070
1200
1200
1200
940
1160
1200
1200
1200
1200
1200
1200
1100
1200
1200
1200
960
1190
1200
1200
660
920
1200
630
880
1160
580
810
1090
620
860
1140
500
720
980
420
620
870
630
870
1150
520
740
1000
440
650
890
2 × 89 × 184
2 × 89 × 235
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
For interpolated values from Table 4.15, use the lower spacing from the two corresponding spacings in this table.
Bolt specifications used; for 38mm, 44mm, 47mm & 63mm wide sections: M12 bolts (min. 3mm x 38mm M12 washers under head & nut),
for 72mm & 89mm wide sections: M16 bolts (min. 4mm x 48mm M16 washers under head & nut).
Each trimming joist should be fixed in line with a minimum of two bolts at 1/3 span positions.
51
Licensed copy: univulster, University of Ulster, 21/08/2017, Uncontrolled Copy, © TRADA Technology
Eurocode 5 span tables for solid timber members
Table 4.28 Bolt centres for double member trimming joists in Table 4.16
Dead loads
This table uses
regularised depth
gk = 0.50 kN/m2
Imposed load not exceeding
qk = 1.5 kN/m
2
or
Qk = 2.0 kN
Strength Class C24
C24
Permanent (Dead) loads gk, excluding self-weights, not more than 0.50 kN/m2
See Figure 4.4 for positions of d1, d2, d3 and S
Trimming joist d1/d2 not more than 0.25
size
Dimension d3 (m)
2 × (mm × mm)
1.0
2.0
d1/d2 not more than 0.50
d1/d2 not more than 0.75
Dimension d3 (m)
3.0
Dimension d3 (m)
1.0
2.0
3.0
1.0
2.0
3.0
Bolt centres S (mm) on Figure 4.2
2 × 38 × 145
2 × 38 × 170
2 × 38 × 195
2 × 38 × 220
790
960
1120
1200
750
910
1070
1200
700
850
1000
1150
740
890
1040
1200
610
760
900
1040
530
660
790
930
750
900
1060
1200
630
770
910
1060
550
680
810
950
2 × 44 × 145
2 × 44 × 170
2 × 44 × 195
2 × 44 × 220
840
1020
1190
1200
800
970
1130
1200
740
900
1060
1200
790
950
1110
1200
660
810
960
1110
860
710
850
990
800
960
1120
1200
680
820
970
1130
890
730
870
1010
2 × 47 × 145
2 × 47 × 170
2 × 47 × 195
2 × 47 × 220
870
1040
1200
1200
830
990
1160
1200
760
920
1090
1200
810
970
1140
1200
1020
830
990
1140
890
730
880
1020
820
980
1150
1200
1050
850
1000
1160
920
750
890
1040
2 × 63 × 145
2 × 63 × 170
2 × 63 × 195
2 × 63 × 220
1200
1170
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1170
1200
1200
1200
1020
1200
1200
1160
1200
1200
1200
1200
1190
1200
1200
1200
1050
1200
1200
1180
2 × 72 × 145
2 × 72 × 170
2 × 72 × 195
2 × 72 × 220
ALS/CLS
2 × 38 × 140
2 × 38 × 184
2 × 38 × 235
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1090
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1120
1200
1200
1200
760
1050
1200
720
1000
1200
670
930
1200
710
980
1200
590
840
1130
500
730
1010
720
990
1200
600
850
1140
520
750
1030
2 × 89 × 184
2 × 89 × 235
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
For interpolated values from Table 4.16, use the lower spacing from the two corresponding spacings in this table.
Bolt specifications used; for 38mm, 44mm, 47mm & 63mm wide sections: M12 bolts (min. 3mm x 38mm M12 washers under head & nut),
for 72mm & 89mm wide sections: M16 bolts (min. 4mm x 48mm M16 washers under head & nut).
Each trimming joist should be fixed in line with a minimum of two bolts at 1/3 span positions.
52
Licensed copy: univulster, University of Ulster, 21/08/2017, Uncontrolled Copy, © TRADA Technology
4 Floor members
Table 4.29 Bolt centres for double member trimming joists in Table 4.17
Dead loads
This table uses
regularised depth
gk = 1.25 kN/m2
Imposed load not exceeding
qk = 1.5 kN/m
2
or
Qk = 2.0 kN
Strength Class C16
C16
Permanent (Dead) loads gk, excluding self-weights, not more than 1.25 kN/m2
See Figure 4.4 for positions of d1, d2, d3 and S
Trimming joist d1/d2 not more than 0.25
size
Dimension d3 (m)
2 × (mm × mm)
1.0
2.0
d1/d2 not more than 0.50
d1/d2 not more than 0.75
Dimension d3 (m)
3.0
Dimension d3 (m)
1.0
2.0
3.0
1.0
2.0
3.0
Bolt centres S (mm) on Figure 4.2
2 × 38 × 145
2 × 38 × 170
2 × 38 × 195
2 × 38 × 220
660
800
940
1080
620
760
890
1020
580
700
830
950
610
740
870
1000
500
620
730
850
430
530
640
750
620
750
880
1010
510
630
750
870
440
550
660
770
2 × 44 × 145
2 × 44 × 170
2 × 44 × 195
2 × 44 × 220
700
850
1000
1140
670
810
950
1080
620
750
880
1010
650
790
920
1060
540
660
790
910
460
570
690
810
660
800
930
1070
550
680
800
920
480
590
710
820
2 × 47 × 145
2 × 47 × 170
2 × 47 × 195
2 × 47 × 220
720
870
1020
1170
690
830
970
1110
630
770
900
1040
670
810
950
1080
560
680
810
940
720
590
710
830
680
820
960
1090
570
700
820
950
490
610
730
850
2 × 63 × 145
2 × 63 × 170
2 × 63 × 195
2 × 63 × 220
1200
980
1150
1200
1170
940
1090
1200
1080
870
1020
1170
1140
910
1060
1200
960
1170
920
1060
840
1030
820
950
1150
920
1070
1200
980
1190
930
1070
860
1050
830
960
2 × 72 × 145
2 × 72 × 170
2 × 72 × 195
2 × 72 × 220
ALS/CLS
2 × 38 × 140
2 × 38 × 184
2 × 38 × 235
1200
1200
1200
1200
1200
1200
1200
1200
1150
1200
1200
1200
1200
1200
1200
1200
1020
1200
1200
1200
890
1100
1200
1200
1200
1200
1200
1200
1040
1200
1200
1200
920
1120
1200
1200
630
880
870
600
830
820
550
770
1030
590
810
1070
480
680
920
400
590
820
600
820
1080
490
700
940
420
610
830
2 × 89 × 184
2 × 89 × 235
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
For interpolated values from Table 4.17, use the lower spacing from the two corresponding spacings in this table.
Bolt specifications used; for 38mm, 44mm, 47mm & 63mm wide sections: M12 bolts (min. 3mm x 38mm M12 washers under head & nut),
for 72mm & 89mm wide sections: M16 bolts (min. 4mm x 48mm M16 washers under head & nut).
Each trimming joist should be fixed in line with a minimum of two bolts at 1/3 span positions.
53
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Eurocode 5 span tables for solid timber members
Table 4.30 Bolt centres for double member trimming joists in Table 4.18
Dead loads
This table uses
regularised depth
gk = 1.25 kN/m2
Imposed load not exceeding
qk = 1.5 kN/m
2
or
Qk = 2.0 kN
Strength Class C24
C24
Permanent (Dead) loads gk, excluding self-weights, not more than 1.25 kN/m2
See Figure 4.4 for positions of d1, d2, d3 and S
Trimming joist d1/d2 not more than 0.25
size
Dimension d3 (m)
2 × (mm × mm)
1.0
2.0
d1/d2 not more than 0.50
d1/d2 not more than 0.75
Dimension d3 (m)
3.0
Dimension d3 (m)
1.0
2.0
3.0
1.0
2.0
3.0
Bolt centres S (mm) on Figure 4.2
2 × 38 × 145
2 × 38 × 170
2 × 38 × 195
2 × 38 × 220
760
910
1070
1200
720
870
1010
1160
660
800
940
1090
700
840
990
1130
580
720
850
980
500
620
750
870
710
850
1000
1140
600
730
860
990
520
640
760
890
2 × 44 × 145
2 × 44 × 170
2 × 44 × 195
2 × 44 × 220
800
970
1130
1200
760
920
1070
1200
710
860
1000
1150
750
900
1050
1200
630
760
900
1040
540
670
800
930
750
910
1060
1200
640
780
920
1060
560
690
820
950
2 × 47 × 145
2 × 47 × 170
2 × 47 × 195
2 × 47 × 220
830
990
1160
1200
790
950
1100
1200
730
880
1030
1180
770
920
1070
1200
650
790
930
1070
850
690
830
960
780
930
1080
1200
660
800
940
1090
870
710
840
970
2 × 63 × 145
2 × 63 × 170
2 × 63 × 195
2 × 63 × 220
1200
1120
1200
1200
1200
1060
1200
1200
1200
990
1160
1200
1200
1030
1200
1200
1110
1200
1050
1200
970
1190
1200
1090
1200
1040
1200
1200
1130
1200
1060
1200
1000
1200
1200
1100
2 × 72 × 145
2 × 72 × 170
2 × 72 × 195
2 × 72 × 220
ALS/CLS
2 × 38 × 140
2 × 38 × 184
2 × 38 × 235
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1170
1200
1200
1200
1030
1200
1200
1200
1200
1200
1200
1200
1190
1200
1200
1200
1060
1200
1200
1200
720
1000
990
690
950
1200
640
880
1170
670
920
1200
560
790
1060
480
690
950
680
930
1200
570
800
1070
500
710
960
2 × 89 × 184
2 × 89 × 235
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
1200
For interpolated values from Table 4.18, use the lower spacing from the two corresponding spacings in this table.
Bolt specifications used; for 38mm, 44mm, 47mm & 63mm wide sections: M12 bolts (min. 3mm x 38mm M12 washers under head & nut),
for 72mm & 89mm wide sections: M16 bolts (min. 4mm x 48mm M16 washers under head & nut).
Each trimming joist should be fixed in line with a minimum of two bolts at 1/3 span positions.
54
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5 Tables of sizes of ceiling members
5.0 Tables of sizes of ceiling members
5.1 Ceiling joists and binders supporting ceiling joists
5.1.1
Tables 5.1 to 5.4 give permissible clear spans of simply supported ceiling joists and single span ceiling
binders of solid timber used in traditional pitched roof constructions (ie excluding trussed rafter roofs)
under specified loading, sizes and spacings calculated in accordance with EC5.
5.1.2
In Figure 5.1, the binders support the joists, so the connections between them need to be designed and
installed properly to ensure that half the load on the two adjacent spans of joist can be transferred to
the binder where it crosses the joists. Suitable nailed metal plate fixtures are recommended to ensure
a good fixing.
5.1.3
Permissible clear spans have been calculated in accordance with EC5. Refer to Section 3.3.1 for
additional information on the method used. Permissible clear span is the largest of: the clear distance
between the first wall plate and first binder, the clear distances between binders, and the clear distance
between last binder and second wall plate. The ceiling joists may be continuous or composed of shorter
lengths, joined at the binder.
5.1.4
The method of calculating ceiling joist sizes does not take account of trimming (eg around flues) or
other loads (eg water tanks).
5.1.5
The sizes, spacing and spans given in Tables 5.1 to 5.4 will support the dead loads stated in the tables
together with an imposed load not exceeding 0.25 kN/m2 and a concentrated load of 0.9kN, acting
together as specified by EC1. For binders, the self-weight of ceiling joists was taken for a system of
50mm x 150mm joists at 450mm centres.
5.1.6
Lateral support is assumed to provide stability to the members designed. EC5 considers the stability
of these members through the use of a modification factor kcrit, which is assumed to be 1.0 throughout
this book. However, unless additional restraint is provided, eg boarding fastened to the upper surface
of the ceiling joists, the depth to breadth ratio of the joists and binders should not generally exceed 4:1.
5.1.7
The minimum bearing length at supports for ceiling joists should be 35mm and binders should be
60mm. However, it is normal for ceiling joists to run across at least the full width of the wallplate to
accommodate the fixings between ceiling joist and rafters.
5.1.8
Notching or drilling of ceiling joists and binders should not be carried out unless justified by specialist
calculation.
5.1.9
The section sizes of ceiling joists given in Tables 5.1 and 5.2 should be machined on the width of the
joist, ie to reduce its depth, to the tolerance classes specified in BS EN 336.
5.1.10
The section sizes of ceiling binders given in Tables 5.3 and 5.4 could either be sawn sections or
be machined on the width of the binder, ie to reduce its depth to the tolerance classes specified in
BS EN 336.
55
Licensed copy: univulster, University of Ulster, 21/08/2017, Uncontrolled Copy, © TRADA Technology
Eurocode 5 span tables for solid timber members
ing s
ac
sp entre
r
c
de
Bin ween
t
e
b
Bin
d
J
be oist s er cle
twe pa
ar
spa
en cin
cen g
n
tre
s
Wall plate
Binder
Support
Ceiling joist
Figure 5.1 Ceiling joists and binder arrangement
56
Licensed copy: univulster, University of Ulster, 21/08/2017, Uncontrolled Copy, © TRADA Technology
5 Tables of sizes of ceiling members
Table 5.1 Permissible clear spans for ceiling joists
Imposed load not exceeding
Strength Class C16
Service Class 1 or 2
Dead loads gk (kN/m²) excluding self-weight of joist
C16
Size of joist
Breadth
(mm)
This table uses
regularised depth
qk = 0.25 kN/m² and Qk = 0.90 kN
Depth
(mm)
gk not more than 0.25
Spacing of joists (mm)
400
450
Maximum clear span (m)
gk not more than 0.5
600
400
450
600
38
38
38
38
38
38
38
72
95
120
145
170
195
220
1.11
1.64
2.25
2.89
3.53
4.18
4.84
1.10
1.62
2.22
2.84
3.47
4.11
4.74
1.07
1.57
2.14
2.72
3.31
3.90
4.50
1.06
1.55
2.11
2.67
3.25
3.83
4.41
1.05
1.53
2.07
2.62
3.18
3.74
4.30
1.01
1.46
1.97
2.48
3.00
3.52
4.04
44
44
44
44
44
44
44
72
95
120
145
170
195
220
1.20
1.76
2.41
3.08
3.75
4.44
5.12
1.19
1.74
2.37
3.03
3.69
4.35
5.02
1.16
1.68
2.28
2.89
3.51
4.13
4.76
1.14
1.66
2.25
2.84
3.45
4.06
4.66
1.13
1.63
2.20
2.79
3.37
3.96
4.55
1.09
1.56
2.09
2.63
3.18
3.72
4.27
72
95
120
145
170
195
220
1.24
1.82
2.48
3.16
3.86
4.55
5.25
1.23
1.80
2.44
3.11
3.79
4.47
5.14
1.19
1.74
2.35
2.97
3.61
4.24
4.88
1.18
1.71
2.31
2.92
3.54
4.16
4.78
1.17
1.68
2.27
2.86
3.46
4.06
4.67
1.12
1.61
2.15
2.71
3.26
3.82
4.38
89
114
140
184
1.50
2.11
2.76
3.90
1.48
2.08
2.72
3.83
1.44
2.00
2.60
3.64
1.42
1.97
2.56
3.57
1.40
1.94
2.51
3.49
1.34
1.84
2.38
3.29
47
47
47
47
47
47
47
ALS/CLS
38
38
38
38
57
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Eurocode 5 span tables for solid timber members
Table 5.2 Permissible clear spans for ceiling joists
Imposed load not exceeding
Strength Class C24
Service Class 1 or 2
Dead loads gk (kN/m²) excluding self-weight of joist
C24
Size of joist
Breadth
(mm)
This table uses
regularised depth
qk = 0.25 kN/m² and Qk = 0.90 kN
Depth
(mm)
gk not more than 0.25
Spacing of joists (mm)
400
450
Maximum clear span (m)
gk not more than 0.5
600
400
450
600
38
38
38
38
38
38
38
72
95
120
145
170
195
220
1.30
1.91
2.60
3.32
4.04
4.77
5.50
1.29
1.89
2.57
3.26
3.97
4.68
5.39
1.26
1.82
2.46
3.11
3.77
4.44
5.10
1.24
1.80
2.42
3.06
3.70
4.35
5.00
1.22
1.77
2.38
3.00
3.62
4.25
4.87
1.18
1.69
2.25
2.83
3.41
3.99
4.57
44
44
44
44
44
44
44
72
95
120
145
170
195
220
1.40
2.04
2.78
3.53
4.28
5.04
5.80
1.39
2.02
2.73
3.47
4.20
4.95
5.69
1.35
1.95
2.62
3.31
4.00
4.69
5.38
1.33
1.92
2.58
3.25
3.92
4.60
5.27
1.31
1.89
2.53
3.18
3.83
4.49
5.14
1.26
1.80
2.40
3.00
3.61
4.21
4.82
72
95
120
145
170
195
220
1.45
2.11
2.86
3.62
4.40
5.17
5.94
1.43
2.08
2.81
3.56
4.31
5.07
5.82
1.39
2.00
2.69
3.40
4.10
4.81
5.51
1.37
1.98
2.65
3.34
4.03
4.71
5.40
1.35
1.94
2.60
3.26
3.93
4.60
5.27
1.30
1.85
2.46
3.08
3.70
4.32
4.94
89
114
140
184
1.75
2.44
3.17
4.45
1.73
2.40
3.12
4.36
1.67
2.31
2.98
4.15
1.65
2.27
2.93
4.07
1.62
2.23
2.87
3.97
1.55
2.12
2.71
3.73
47
47
47
47
47
47
47
ALS/CLS
38
38
38
38
58
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5 Tables of sizes of ceiling members
Table 5.3 Permissible clear spans for ceiling binders
Imposed load not exceeding
This table uses
target (= sawn) depth
qk = 0.25 kN/m² and Qk = 0.90 kN
Service Class 1 or 2
Strength Class C16
gk (kN/m²) excluding self weight of binder
gk not more than 0.25
gk not more than 0.50
C16
Dead loads
Size of binder
Breadth Depth
(mm)
(mm)
Spacing of binders (mm)
1200
1500
1800
Maximum clear span (m)
2100
2400
2700
1200
1500
1800
2100
2400
2700
44
44
44
150
175
200
2.42
2.88
3.34
2.28
2.71
3.14
2.17
2.58
2.98
2.08
2.46
2.84
2.00
2.36
2.72
1.93
2.27
2.62
2.15
2.55
2.95
2.02
2.39
2.76
1.91
2.26
2.61
1.82
2.15
2.48
1.74
2.06
2.37
1.66
1.98
2.28
47
47
47
150
175
200
2.48
2.95
3.43
2.34
2.78
3.22
2.23
2.65
3.05
2.14
2.52
2.91
2.05
2.42
2.79
1.98
2.33
2.69
2.21
2.62
3.03
2.07
2.45
2.83
1.96
2.32
2.68
1.87
2.21
2.55
1.80
2.12
2.43
1.73
2.03
2.34
63
63
63
63
63
125
150
175
200
225
2.26
2.78
3.30
3.82
4.33
2.14
2.63
3.11
3.59
4.06
2.04
2.50
2.95
3.40
3.84
1.96
2.39
2.82
3.24
3.67
1.89
2.30
2.71
3.11
3.52
1.82
2.22
2.61
3.00
3.39
2.02
2.47
2.93
3.38
3.83
1.90
2.32
2.74
3.16
3.58
1.80
2.20
2.60
2.99
3.38
1.72
2.10
2.47
2.84
3.21
1.66
2.02
2.37
2.72
3.07
1.60
1.94
2.28
2.62
2.95
72
72
72
72
72
125
150
175
200
225
2.38
2.93
3.47
4.01
4.54
2.26
2.76
3.27
3.76
4.25
2.15
2.63
3.10
3.57
4.03
2.07
2.51
2.96
3.40
3.85
1.99
2.42
2.84
3.27
3.69
1.92
2.33
2.74
3.15
3.56
2.13
2.60
3.08
3.55
4.02
2.00
2.44
2.89
3.32
3.75
1.90
2.32
2.73
3.14
3.54
1.82
2.21
2.60
2.99
3.37
1.75
2.12
2.49
2.86
3.23
1.68
2.04
2.40
2.75
3.10
Table 5.4 Permissible clear spans for ceiling binders
Imposed load not exceeding 0.25 kN/m² and
This table uses
target (= sawn) depth
Qk = 0.90 kN
C24
qk = Service Class 1 or 2
Dead loads gk (kN/m²) excluding self weight of binder
gk not more than 0.25
gk not more than 0.50
Size of binder
Breadth Depth
(mm)
(mm)
Spacing of binders (mm)
1200
1500
1800
Maximum clear span (m)
Strength Class C24
2100
2400
2700
1200
1500
1800
2100
2400
2700
44
44
44
150
175
200
2.73
3.24
3.75
2.57
3.05
3.52
2.45
2.89
3.33
2.34
2.76
3.18
2.25
2.65
3.05
2.17
2.55
2.93
2.43
2.87
3.32
2.28
2.69
3.11
2.16
2.55
2.93
2.06
2.42
2.79
1.97
2.32
2.67
1.90
2.23
2.56
47
47
47
150
175
200
2.80
3.32
3.85
2.64
3.13
3.61
2.51
2.97
3.41
2.40
2.83
3.26
2.31
2.71
3.12
2.22
2.62
3.01
2.49
2.95
3.40
2.34
2.76
3.18
2.21
2.61
3.00
2.11
2.48
2.86
2.02
2.38
2.73
1.95
2.29
2.63
63
63
63
63
63
125
150
175
200
225
2.55
3.13
3.71
4.27
4.83
2.41
2.95
3.48
4.01
4.53
2.30
2.80
3.30
3.79
4.29
2.21
2.68
3.15
3.62
4.09
2.12
2.57
3.02
3.47
3.92
2.05
2.48
2.91
3.35
3.78
2.28
2.78
3.29
3.79
4.28
2.14
2.61
3.08
3.54
4.00
2.03
2.48
2.91
3.34
3.77
1.94
2.36
2.77
3.18
3.59
1.87
2.26
2.65
3.05
3.44
1.80
2.18
2.55
2.93
3.31
72
72
72
72
72
125
150
175
200
225
2.69
3.29
3.89
4.47
5.05
2.54
3.10
3.65
4.20
4.74
2.42
2.94
3.46
3.98
4.49
2.32
2.81
3.31
3.80
4.29
2.23
2.70
3.17
3.64
4.11
2.15
2.61
3.06
3.51
3.96
2.40
2.92
3.45
3.97
4.48
2.25
2.74
3.23
3.71
4.19
2.14
2.60
3.05
3.51
3.96
2.04
2.48
2.91
3.34
3.77
1.96
2.38
2.79
3.20
3.61
1.89
2.29
2.68
3.08
3.47
59
6.0 Tables of sizes of pitched roof members
P
be url
tw in
ee sp
n ac
ce in
nt g
re
Cl
s
ea
of r s
ra pa
fte n
r
6.1 Rafters and purlins supporting rafters
Ridgeboard
Rafter
P
be url
tw in
ee sp
n ac
ce in
nt g
re
s
Cl
ea
of r s
ra pa
fte n
r
Licensed copy: univulster, University of Ulster, 21/08/2017, Uncontrolled Copy, © TRADA Technology
Eurocode 5 span tables for solid timber members
Purlin
Wall plate
Figure 6.1 Typical rafters and purlin arrangement
6.1.1
Tables 6.1 to 6.24 give permissible clear spans of simply supported rafters and purlins of solid timber
used in traditional pitched roof constructions with a slope from 15° to 45° under specified loading, sizing
and spacing conditions.
6.1.2
These span tables do not apply to trussed rafter roofs.
6.1.3
Permissible clear spans have been calculated in accordance with EC5. Refer to Section 3.3.1 for
additional information on the method used. It is assumed that the rafters are non-continuous over the
purlins, but they may be continuous. It is assumed that the purlins are single span members but they
may be continuous over a support.
6.1.4
When the spans of the rafters or purlins are unequal, the section sizes should be determined by the
longest span. For a purlin spanning between two supporting walls, the longest span is the clear distance
between the two walls. For a purlin with an intermediate post, the longest span is the larger of the clear
distance between one wall and the post and the clear distance between the post and the other wall.
6.1.5
For Tables 6.1 to 6.24 the values have been calculated according to EC5 with an upper limit on the roof
slope of 60° for the imposed snow load.
6.1.6
The method of calculation makes no allowance for any contribution of other parts of the roof structure
or covering to the load carrying capacity of the rafters although it is assumed that the tiling battens are
capable of providing lateral load distribution and lateral support.
6.1.7
These span tables cover 'canted' purlins installed perpendicular to the slope of the roof. Horizontal
thrust transmitted by the rafters is assumed to be restrained by the ceiling joists or other suitable means.
6.1.8
The sizes, spacing and spans given in Tables 6.1 to 6.24 will support the dead loads stated in the tables
together with either an imposed load of 0.60 kN/m2 or 1.02 kN/m2 or a concentrated load of 0.9 kN. The
dead load is measured on slope and the snow load is measured on plan.
See Figure 3.1 and Table 3.1 for guidance on the snow load relevant for a particular site.
For purlins, the self-weight of rafters was taken for system of 50mm x 150mm rafters at 450mm centres.
60
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6 Tables of sizes of pitched roof members
6.1.9
Rafters are considered to provide lateral support to purlins. EC5 considers the stability of these
members through the use of a modification factor kcrit – assumed to be 1.0 throughout this book. If lateral
support is not sufficient, purlin depth to breadth ratio should not exceed 4:1.
6.1.10
Notching or drilling of rafters and purlins should not be carried out unless justified by specialist
calculation.
6.1.11
Unless justified by specialist calculation, the minimum bearing length at supports should be 35mm for
rafters and 60mm for purlins. However it may sometimes be necessary to provide longer bearing for
practical reasons. Where longer bearing is required due to high bearing stresses in calculations for
larger sections used as purlins, it is indicated in the tables by shading where the bearing length should
be increased to 80mm.
6.1.12
The section sizes of rafters and purlins given in Tables 6.1 to 6.24 should be sawn sections or be
machined on the width of the rafter or purlin, ie to reduce its depth to the tolerance classes specified
in BS EN 336.
6.1.13
Calculations are not normally required for hip and valley rafters or ridge boards, provided the roof is tied
at ceiling height to prevent it spreading. Continuous or tension-spliced ceiling joints that are fixed to the
ends of the rafters normally provide sufficient resistance to spreading.
Hip and valley rafter and ridge boards should be:
• deep enough to provide a contact face to the full depth of the cut rafter
• wide enough to accomodate the full length of the fasteners.
Assumptions:
• The hip and valley rafters and ridge boards are restrained from twisting and buckling by the rafters.
If the rafter spacing is greater than 600mm, this assumption may not apply.
• The hip and valley rafters and ridge boards are single continuous members.
• The hip and valley rafters and ridge boards are cut from strength graded timber.
61
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Eurocode 5 span tables for solid timber members
Table 6.1 Permissible clear spans for single-span common or jack rafters
Slope of roof 15° or more but less than 22.5°
Strength Class C16
Imposed load
This table uses
target (= sawn) depth
qk = 0.60 kN/m² or Qk = 0.90 kN
Service Class 1 or 2
C16
Dead loads gk (kN/m²) excluding self-weight of rafter
Size of rafter
Breadth
Depth
(mm)
(mm)
Spacing of rafters (mm)
400
450
Maximum clear span (m)
gk not more than 0.5
gk not more than 0.75
gk not more than 1.00
600
400
450
600
400
450
600
38
38
38
38
100
125
150
195
1.74
2.34
2.95
4.06
1.72
2.30
2.89
3.97
1.65
2.19
2.75
3.75
1.65
2.19
2.75
3.75
1.62
2.15
2.68
3.66
1.54
2.03
2.53
3.43
1.57
2.08
2.59
3.53
1.54
2.03
2.53
3.43
1.46
1.91
2.37
3.20
44
44
44
44
100
125
150
195
1.86
2.49
3.13
4.30
1.84
2.45
3.07
4.21
1.76
2.34
2.92
3.97
1.76
2.34
2.92
3.97
1.73
2.29
2.85
3.88
1.64
2.16
2.68
3.63
1.68
2.21
2.75
3.73
1.64
2.16
2.68
3.63
1.55
2.03
2.51
3.38
100
125
150
195
1.92
2.56
3.22
4.41
1.89
2.52
3.16
4.32
1.81
2.40
3.00
4.08
1.81
2.40
3.00
4.08
1.78
2.35
2.93
3.98
1.69
2.22
2.76
3.72
1.73
2.28
2.83
3.83
1.69
2.22
2.76
3.72
1.60
2.09
2.58
3.47
114
140
184
2.07
2.70
3.79
2.04
2.65
3.71
1.95
2.52
3.51
1.95
2.52
3.51
1.91
2.47
3.42
1.81
2.33
3.21
1.86
2.39
3.30
1.81
2.33
3.21
1.71
2.18
2.99
47
47
47
47
ALS/CLS
38
38
38
Table 6.2 Permissible clear spans for single-span common or jack rafters
Slope of roof 15° or more but less than 22.5°
Strength Class C24
Imposed load
This table uses
target (= sawn) depth
qk = 0.60 kN/m² or Qk = 0.90 kN
Service Class 1 or 2
C24
Dead loads gk (kN/m²) excluding self-weight of rafter
Size of rafter
Breadth
Depth
(mm)
(mm)
Spacing of rafters (mm)
400
450
Maximum clear span (m)
gk not more than 0.5
gk not more than 0.75
gk not more than 1.00
600
400
450
600
400
450
600
38
38
38
38
100
125
150
195
2.02
2.69
3.37
4.62
1.98
2.64
3.31
4.52
1.90
2.51
3.13
4.24
1.90
2.51
3.13
4.26
1.87
2.46
3.06
4.15
1.77
2.32
2.88
3.88
1.81
2.38
2.95
3.99
1.77
2.32
2.88
3.88
1.67
2.18
2.69
3.61
44
44
44
44
100
125
150
195
2.15
2.86
3.58
4.88
2.12
2.81
3.51
4.77
2.03
2.67
3.32
4.45
2.03
2.67
3.32
4.50
1.99
2.61
3.25
4.39
1.89
2.47
3.05
4.10
1.93
2.53
3.13
4.22
1.89
2.47
3.05
4.10
1.78
2.31
2.85
3.82
100
125
150
195
2.22
2.94
3.67
5.00
2.18
2.88
3.60
4.89
2.09
2.74
3.41
4.55
2.09
2.74
3.41
4.61
2.04
2.68
3.33
4.50
1.94
2.53
3.13
4.20
1.98
2.60
3.21
4.33
1.94
2.53
3.13
4.21
1.83
2.37
2.92
3.91
114
140
184
2.39
3.10
4.31
2.35
3.04
4.22
2.24
2.89
3.98
2.24
2.89
3.98
2.20
2.82
3.89
2.08
2.66
3.64
2.13
2.72
3.74
2.08
2.66
3.64
1.96
2.49
3.39
47
47
47
47
ALS/CLS
38
38
38
62
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6 Tables of sizes of pitched roof members
Table 6.3 Permissible clear spans for purlins supporting single-span rafters
Slope of roof 15° or more but less than 22.5°
Strength Class C16
C16
Imposed load
This table uses
target (= sawn) depth
qk = 0.60 kN/m² or Qk = 0.90 kN
Service Class 1 or 2
Dead loads gk (kN/m²) excluding self-weight of purlin
gk not more than 0.5
gk not more than 0.75
gk not more than 1.00
Size of
Spacing of purlins (mm)
purlin
B'dth D'pth 1500 1800 2100 2400 2700 3000 1500 1800 2100 2400 2700 3000 1500 1800 2100 2400 2700 3000
(mm) (mm) Maximum clear span (m)
63
63
63
63
63
150
175
200
225
275
2.31
2.70
3.08
3.46
4.22
2.17
2.53
2.89
3.25
3.96
2.05
2.39
2.73
3.07
3.75
1.94
2.26
2.58
2.90
3.54
1.83
2.13
2.43
2.73
3.34
1.73
2.02
2.30
2.59
3.16
2.13
2.49
2.84
3.19
3.89
2.00
2.33
2.66
2.99
3.65
1.89
2.20
2.51
2.82
3.45
1.76
2.05
2.34
2.64
3.22
1.66
1.93
2.21
2.48
3.03
1.57
1.83
2.09
2.35
2.87
1.99
2.32
2.66
2.98
3.64
1.87
2.17
2.48
2.79
3.41
1.74
2.03
2.31
2.60
3.18
1.62
1.89
2.16
2.43
2.96
1.52
1.78
2.03
2.28
2.79
1.44
1.68
1.92
2.16
2.64
72
72
72
72
72
125
150
175
200
225
2.02
2.43
2.83
3.23
3.62
1.90
2.28
2.65
3.03
3.40
1.80
2.15
2.51
2.87
3.22
1.71
2.05
2.39
2.73
3.07
1.64
1.96
2.28
2.61
2.93
1.57
1.85
2.16
2.47
2.77
1.87
2.24
2.61
2.98
3.35
1.75
2.10
2.44
2.79
3.14
1.65
1.98
2.31
2.64
2.97
1.57
1.89
2.20
2.51
2.82
1.51
1.78
2.07
2.36
2.66
1.43
1.68
1.96
2.24
2.52
1.75
2.09
2.44
2.79
3.13
1.63
1.96
2.28
2.61
2.93
1.54
1.85
2.16
2.47
2.77
1.47
1.74
2.03
2.31
2.60
1.39
1.63
1.91
2.18
2.45
1.31
1.55
1.80
2.06
2.32
Nominal bearing increased to 80mm - See Section 6.1.11
Table 6.4 Permissible clear spans for purlins supporting single-span rafters
Slope of roof 15° or more but less than 22.5°
Strength Class C24
C24
Imposed load
This table uses
target (= sawn) depth
qk = 0.60 kN/m² or Qk = 0.90 kN
Service Class 1 or 2
Dead loads gk (kN/m²) excluding self-weight of purlin
gk not more than 0.5
gk not more than 0.75
gk not more than 1.00
Size of
Spacing of purlins (mm)
purlin
B'dth D'pth 1500 1800 2100 2400 2700 3000 1500 1800 2100 2400 2700 3000 1500 1800 2100 2400 2700 3000
(mm) (mm) Maximum clear span (m)
63
63
63
63
63
150
175
200
225
275
2.58
3.00
3.43
3.85
4.70
2.42
2.82
3.22
3.62
4.41
2.29
2.67
3.05
3.43
4.18
2.18
2.55
2.91
3.27
3.99
2.09
2.44
2.79
3.13
3.82
2.01
2.35
2.68
3.01
3.68
2.38
2.77
3.17
3.56
4.34
2.23
2.60
2.97
3.34
4.07
2.11
2.46
2.81
3.16
3.85
2.01
2.34
2.68
3.01
3.67
1.92
2.24
2.56
2.88
3.52
1.85
2.16
2.46
2.77
3.38
2.23
2.60
2.97
3.33
4.07
2.09
2.43
2.78
3.12
3.81
1.97
2.30
2.63
2.95
3.60
1.88
2.19
2.50
2.81
3.43
1.80
2.09
2.39
2.69
3.28
1.72
2.01
2.30
2.58
3.15
72
72
72
72
72
125
150
175
200
225
2.25
2.70
3.15
3.59
4.03
2.11
2.53
2.95
3.37
3.79
2.00
2.40
2.80
3.20
3.59
1.91
2.29
2.67
3.05
3.43
1.83
2.20
2.56
2.92
3.29
1.76
2.11
2.46
2.81
3.16
2.08
2.49
2.91
3.32
3.73
1.95
2.34
2.73
3.11
3.50
1.85
2.21
2.58
2.95
3.31
1.76
2.11
2.46
2.81
3.16
1.69
2.02
2.36
2.69
3.03
1.62
1.94
2.27
2.59
2.91
1.95
2.34
2.72
3.11
3.49
1.83
2.19
2.55
2.91
3.28
1.73
2.07
2.41
2.76
3.10
1.64
1.97
2.30
2.63
2.95
1.57
1.89
2.20
2.51
2.83
1.51
1.81
2.12
2.42
2.72
Nominal bearing increased to 80mm - See Section 6.1.11
63
Licensed copy: univulster, University of Ulster, 21/08/2017, Uncontrolled Copy, © TRADA Technology
Eurocode 5 span tables for solid timber members
Table 6.5 Permissible clear spans for single-span common or jack rafters
This table uses
target (= sawn) depth
Slope of roof 15° or more but not more than 22.5° Imposed load qk = 1.02 kN/m² or Qk = 0.90 kN
Strength Class C16
Service Class 1 or 2
C16
Dead loads gk (kN/m²) excluding self-weight of rafter
Size of rafter
Breadth
Depth
(mm)
(mm)
Spacing of rafters (mm)
400
450
Maximum clear span (m)
gk not more than 0.5
gk not more than 0.75
gk not more than 1.00
600
400
450
600
400
450
600
38
38
38
38
100
125
150
195
1.74
2.34
2.95
4.06
1.72
2.30
2.89
3.97
1.65
2.19
2.74
3.62
1.65
2.19
2.75
3.75
1.62
2.15
2.68
3.66
1.54
2.03
2.53
3.37
1.57
2.08
2.59
3.53
1.54
2.03
2.53
3.43
1.46
1.91
2.37
3.17
44
44
44
44
100
125
150
195
1.86
2.49
3.13
4.30
1.84
2.45
3.07
4.18
1.76
2.34
2.92
3.80
1.76
2.34
2.92
3.97
1.73
2.29
2.85
3.87
1.64
2.16
2.68
3.54
1.68
2.21
2.75
3.73
1.64
2.16
2.68
3.63
1.55
2.03
2.51
3.34
100
125
150
195
1.92
2.56
3.22
4.41
1.89
2.52
3.16
4.27
1.81
2.40
3.00
3.89
1.81
2.40
3.00
4.08
1.78
2.35
2.93
3.97
1.69
2.22
2.76
3.62
1.73
2.28
2.83
3.83
1.69
2.22
2.76
3.72
1.60
2.09
2.58
3.41
114
140
184
2.07
2.70
3.79
2.04
2.65
3.71
1.95
2.52
1.95
2.52
3.51
1.91
2.47
3.42
1.81
2.33
1.86
2.39
3.30
1.81
2.33
1.71
2.18
3.21
2.99
47
47
47
47
ALS/CLS
38
38
38
3.42
3.18
Table 6.6 Permissible clear spans for single-span common or jack rafters
Slope of roof 15.0° or more but less than 22.5°
Strength Class C24
Imposed load
This table uses
target (= sawn) depth
qk = 1.02 kN/m² or Qk = 0.90 kN
Service Class 1 or 2
C24
Dead loads gk (kN/m²) excluding self-weight of rafter
Size of rafter
Breadth
Depth
(mm)
(mm)
Spacing of rafters (mm)
400
450
Maximum clear span (m)
gk not more than 0.5
gk not more than 0.75
gk not more than 1.00
600
400
450
600
400
450
600
38
38
38
38
100
125
150
195
2.02
2.69
3.37
4.60
1.98
2.64
3.31
4.43
1.90
2.51
3.11
4.03
1.90
2.51
3.13
4.26
1.87
2.46
3.06
4.13
1.77
2.32
2.88
3.76
1.81
2.38
2.95
3.99
1.77
2.32
2.88
3.88
1.67
2.18
2.69
3.54
44
44
44
44
100
125
150
195
2.15
2.86
3.58
4.82
2.12
2.81
3.51
4.65
2.03
2.67
3.27
4.23
2.03
2.67
3.32
4.50
1.99
2.61
3.25
4.34
1.89
2.47
3.04
3.94
1.93
2.53
3.13
4.22
1.89
2.47
3.05
4.09
1.78
2.31
2.85
3.72
100
125
150
195
2.22
2.94
3.67
4.92
2.18
2.88
3.60
4.74
2.09
2.74
3.34
4.32
2.09
2.74
3.41
4.60
2.04
2.68
3.33
4.43
1.94
2.53
3.11
4.03
1.98
2.60
3.21
4.32
1.94
2.53
3.13
4.18
1.83
2.37
2.92
3.80
114
140
184
2.39
3.10
4.31
2.35
3.04
4.19
2.24
2.88
3.81
2.24
2.89
3.98
2.20
2.82
3.88
2.08
2.65
3.55
2.13
2.72
3.74
2.08
2.66
3.64
1.96
2.49
3.34
47
47
47
47
ALS/CLS
38
38
38
64
Licensed copy: univulster, University of Ulster, 21/08/2017, Uncontrolled Copy, © TRADA Technology
6 Tables of sizes of pitched roof members
Table 6.7 Permissible clear spans for purlins supporting single-span rafters
Slope of roof 15° or more but less than 22.5°
This table uses
target (= sawn) depth
qk = 1.02 kN/m² or Qk = 0.90 kN
Service Class 1 or 2
Strength Class C16
C16
Imposed load
Dead loads gk (kN/m²) excluding self-weight of purlin
gk not more than 0.5
gk not more than 0.75
gk not more than 1.00
Size of
Spacing of purlins (mm)
purlin
B'dth D'pth 1500 1800 2100 2400 2700 3000 1500 1800 2100 2400 2700 3000 1500 1800 2100 2400 2700 3000
(mm) (mm) Maximum clear span (m)
63
63
63
63
63
150
175
200
225
275
2.10
2.45
2.79
3.14
3.83
1.91
2.23
2.54
2.86
3.49
1.76
2.06
2.35
2.64
3.22
1.65
1.92
2.19
2.47
3.01
1.55
1.80
2.06
2.32
2.83
1.46
1.71
1.95
2.19
2.68
1.95
2.28
2.60
2.92
3.57
1.78
2.07
2.37
2.66
3.25
1.64
1.91
2.18
2.46
3.00
1.53
1.78
2.04
2.29
2.80
1.44
1.68
1.91
2.15
2.63
1.36
1.58
1.81
2.03
2.49
1.83
2.14
2.44
2.74
3.35
1.67
1.94
2.22
2.50
3.05
1.54
1.79
2.05
2.30
2.81
1.43
1.67
1.91
2.15
2.62
1.35
1.57
1.79
2.02
2.46
1.27
1.48
1.69
1.90
2.33
72
72
72
72
72
125
150
175
200
225
1.91
2.25
2.62
2.99
3.36
1.74
2.05
2.39
2.72
3.06
1.61
1.89
2.20
2.52
2.83
1.50
1.76
2.06
2.35
2.64
1.41
1.66
1.94
2.21
2.49
1.33
1.57
1.83
2.09
2.35
1.78
2.09
2.44
2.78
3.13
1.62
1.90
2.22
2.54
2.85
1.49
1.76
2.05
2.34
2.63
1.39
1.64
1.91
2.18
2.46
1.31
1.54
1.80
2.05
2.31
1.24
1.46
1.70
1.94
2.18
1.67
1.96
2.29
2.61
2.94
1.52
1.79
2.08
2.38
2.67
1.40
1.65
1.92
2.20
2.47
1.31
1.54
1.79
2.05
2.30
1.23
1.44
1.68
1.92
2.16
1.16
1.37
1.59
1.82
2.05
Nominal bearing increased to 80mm - See Section 6.1.11
Table 6.8 Permissible clear spans for purlins supporting single-span rafters
Slope of roof 15° or more but less than 22.5°
Strength Class C24
C24
Imposed load
This table uses
target (= sawn) depth
qk = 1.02 kN/m² or Qk = 0.90 kN
Service Class 1 or 2
Dead loads gk (kN/m²) excluding self-weight of purlin
gk not more than 0.5
gk not more than 0.75
gk not more than 1.00
Size of
Spacing of purlins (mm)
purlin
B'dth D'pth 1500 1800 2100 2400 2700 3000 1500 1800 2100 2400 2700 3000 1500 1800 2100 2400 2700 3000
(mm) (mm) Maximum clear span (m)
63
63
63
63
63
150
175
200
225
275
2.45
2.85
3.26
3.66
4.46
2.29
2.67
3.05
3.43
4.19
2.16
2.52
2.88
3.23
3.95
2.02
2.35
2.69
3.02
3.68
1.90
2.21
2.53
2.84
3.47
1.79
2.09
2.39
2.69
3.28
2.28
2.66
3.03
3.41
4.16
2.13
2.49
2.84
3.19
3.90
2.01
2.34
2.68
3.01
3.67
1.87
2.19
2.50
2.81
3.43
1.76
2.05
2.35
2.64
3.22
1.67
1.94
2.22
2.50
3.05
2.15
2.5
2.86
3.21
3.92
2.01
2.34
2.67
3.01
3.67
1.89
2.20
2.51
2.82
3.45
1.76
2.05
2.34
2.63
3.21
1.65
1.93
2.20
2.47
3.02
1.56
1.82
2.08
2.34
2.86
72
72
72
72
72
125
150
175
200
225
2.14
2.57
2.99
3.41
3.83
2.01
2.41
2.80
3.20
3.60
1.90
2.28
2.65
3.03
3.41
1.81
2.16
2.52
2.88
3.23
1.73
2.03
2.37
2.71
3.04
1.63
1.92
2.24
2.56
2.88
1.99
2.39
2.79
3.18
3.58
1.87
2.24
2.61
2.98
3.35
1.77
2.12
2.47
2.82
3.17
1.68
2.01
2.34
2.68
3.01
1.61
1.89
2.20
2.52
2.83
1.52
1.79
2.09
2.38
2.68
1.88
2.25
2.63
3.00
3.37
1.76
2.11
2.46
2.81
3.16
1.66
1.99
2.32
2.65
2.98
1.58
1.89
2.20
2.51
2.82
1.50
1.77
2.07
2.36
2.65
1.42
1.68
1.95
2.23
2.51
Nominal bearing increased to 80mm - See Section 6.1.11
65
Licensed copy: univulster, University of Ulster, 21/08/2017, Uncontrolled Copy, © TRADA Technology
Eurocode 5 span tables for solid timber members
Table 6.9 Permissible clear spans for single-span common or jack rafters
Slope of roof 22.5° or more but less than 30.0°
Strength Class C16
Imposed load
This table uses
target (= sawn) depth
qk = 0.60 kN/m² or Qk = 0.90 kN
Service Class 1 or 2
C16
Dead loads gk (kN/m²) excluding self-weight of rafter
Size of rafter
Breadth
Depth
(mm)
(mm)
Spacing of rafters (mm)
400
450
Maximum clear span (m)
gk not more than 0.5
gk not more than 0.75
gk not more than 1.00
600
400
450
600
400
450
600
38
38
38
38
100
125
150
195
1.78
2.38
3.00
4.14
1.75
2.34
2.95
4.05
1.68
2.24
2.80
3.82
1.68
2.24
2.80
3.82
1.65
2.19
2.74
3.73
1.57
2.07
2.58
3.49
1.61
2.12
2.64
3.59
1.57
2.07
2.58
3.49
1.49
1.95
2.41
3.25
44
44
44
44
100
125
150
195
1.90
2.54
3.19
4.38
1.87
2.50
3.13
4.29
1.80
2.38
2.97
4.05
1.80
2.38
2.97
4.05
1.76
2.33
2.91
3.95
1.68
2.20
2.73
3.70
1.71
2.26
2.81
3.80
1.68
2.20
2.73
3.70
1.58
2.07
2.56
3.44
100
125
150
195
1.96
2.61
3.28
4.49
1.93
2.57
3.22
4.40
1.85
2.45
3.05
4.15
1.85
2.45
3.05
4.15
1.82
2.40
2.98
4.05
1.73
2.26
2.81
3.79
1.76
2.32
2.88
3.90
1.73
2.26
2.81
3.79
1.63
2.13
2.63
3.53
114
140
184
2.12
2.75
3.86
2.08
2.70
3.78
1.99
2.57
3.57
1.99
2.57
3.57
1.95
2.52
3.49
1.85
2.37
3.27
1.89
2.43
3.36
1.85
2.37
3.27
1.74
2.23
3.05
47
47
47
47
ALS/CLS
38
38
38
Table 6.10 Permissible clear spans for single-span common or jack rafters
Slope of roof 22.5° or more but less than 30.0°
Strength Class C24
Imposed load
This table uses
target (= sawn) depth
qk = 0.60 kN/m² or Qk = 0.90 kN
Service Class 1 or 2
C24
Dead loads gk (kN/m²) excluding self-weight of rafter
Size of rafter
Breadth
Depth
(mm)
(mm)
Spacing of rafters (mm)
400
450
Maximum clear span (m)
gk not more than 0.5
gk not more than 0.75
gk not more than 1.00
600
400
450
600
400
450
600
38
38
38
38
100
125
150
195
2.06
2.74
3.44
4.70
2.03
2.69
3.37
4.60
1.94
2.56
3.19
4.34
1.94
2.56
3.19
4.34
1.90
2.51
3.12
4.23
1.81
2.37
2.93
3.95
1.85
2.42
3.01
4.07
1.81
2.37
2.93
3.95
1.70
2.22
2.74
3.68
44
44
44
44
100
125
150
195
2.20
2.92
3.65
4.97
2.16
2.86
3.57
4.86
2.07
2.72
3.39
4.55
2.07
2.72
3.39
4.58
2.03
2.66
3.31
4.47
1.92
2.51
3.11
4.18
1.97
2.57
3.19
4.30
1.92
2.51
3.11
4.18
1.81
2.36
2.90
3.89
100
125
150
195
2.26
3.00
3.74
5.09
2.22
2.94
3.67
4.98
2.13
2.80
3.47
4.65
2.13
2.80
3.47
4.70
2.08
2.74
3.39
4.58
1.98
2.58
3.19
4.28
2.02
2.64
3.27
4.40
1.98
2.58
3.19
4.28
1.86
2.42
2.98
3.98
114
140
184
2.44
3.16
4.39
2.40
3.10
4.30
2.29
2.94
4.06
2.29
2.94
4.06
2.24
2.87
3.96
2.12
2.71
3.70
2.17
2.77
3.81
2.12
2.71
3.70
1.99
2.53
3.45
47
47
47
47
ALS/CLS
38
38
38
66
Licensed copy: univulster, University of Ulster, 21/08/2017, Uncontrolled Copy, © TRADA Technology
6 Tables of sizes of pitched roof members
Table 6.11 Permissible clear spans for purlins supporting single-span rafters
Slope of roof 22.5° or more but less than 30.0°
This table uses
target (= sawn) depth
qk = 0.60 kN/m² or Qk = 0.90 kN
Service Class 1 or 2
Strength Class C16
C16
Imposed load
Dead loads gk (kN/m²) excluding self-weight of purlin
gk not more than 0.5
gk not more than 0.75
gk not more than 1.00
Size of
Spacing of purlins (mm)
purlin
B'dth D'pth 1500 1800 2100 2400 2700 3000 1500 1800 2100 2400 2700 3000 1500 1800 2100 2400 2700 3000
(mm) (mm) Maximum clear span (m)
63
63
63
63
63
150
175
200
225
275
2.37
2.76
3.15
3.54
4.32
2.22
2.59
2.95
3.32
4.05
2.10
2.45
2.80
3.14
3.84
2.00
2.33
2.66
3.00
3.66
1.89
2.21
2.52
2.83
3.46
1.79
2.09
2.39
2.68
3.27
2.18
2.54
2.90
3.26
3.98
2.04
2.38
2.72
3.05
3.73
1.93
2.25
2.57
2.89
3.53
1.82
2.12
2.42
2.73
3.33
1.71
2.00
2.28
2.56
3.13
1.62
1.89
2.16
2.43
2.96
2.04
2.37
2.71
3.05
3.72
1.91
2.22
2.54
2.85
3.48
1.79
2.09
2.39
2.69
3.28
1.67
1.95
2.23
2.51
3.06
1.57
1.84
2.10
2.36
2.88
1.49
1.74
1.98
2.23
2.72
72
72
72
72
72
125
150
175
200
225
2.07
2.48
2.89
3.30
3.71
1.94
2.33
2.71
3.10
3.48
1.84
2.20
2.57
2.93
3.30
1.75
2.10
2.45
2.80
3.14
1.68
2.01
2.35
2.68
3.01
1.61
1.92
2.24
2.56
2.87
1.91
2.29
2.66
3.04
3.42
1.79
2.14
2.50
2.85
3.20
1.69
2.03
2.36
2.70
3.03
1.61
1.93
2.25
2.57
2.89
1.54
1.84
2.14
2.44
2.75
1.48
1.74
2.03
2.31
2.60
1.78
2.14
2.49
2.84
3.20
1.67
2.00
2.33
2.66
2.99
1.58
1.89
2.20
2.52
2.83
1.50
1.79
2.09
2.39
2.69
1.43
1.69
1.97
2.25
2.53
1.36
1.60
1.86
2.13
2.39
Nominal bearing increased to 80mm - See Section 6.1.11
Table 6.12 Permissible clear spans for purlins supporting single-span rafters
Slope of roof 22.5° or more but less than 30.0°
Strength Class C24
C24
Imposed load
This table uses
target (= sawn) depth
qk = 0.60 kN/m² or Qk = 0.90 kN
Service Class 1 or 2
Dead loads gk (kN/m²) excluding self-weight of purlin
gk not more than 0.5
gk not more than 0.75
gk not more than 1.00
Size of
Spacing of purlins (mm)
purlin
B'dth D'pth 1500 1800 2100 2400 2700 3000 1500 1800 2100 2400 2700 3000 1500 1800 2100 2400 2700 3000
(mm) (mm) Maximum clear span (mm)
63
63
63
63
63
150
175
200
225
275
2.64
3.07
3.51
3.94
4.80
2.47
2.88
3.29
3.70
4.51
2.34
2.73
3.12
3.50
4.28
2.23
2.60
2.97
3.34
4.08
2.14
2.50
2.85
3.20
3.91
2.06
2.40
2.74
3.08
3.76
2.43
2.83
3.23
3.63
4.43
2.28
2.66
3.03
3.41
4.16
2.16
2.51
2.87
3.23
3.94
2.05
2.39
2.74
3.08
3.75
1.97
2.29
2.62
2.95
3.60
1.89
2.21
2.52
2.83
3.46
2.27
2.65
3.03
3.40
4.15
2.13
2.48
2.84
3.19
3.89
2.01
2.35
2.68
3.02
3.68
1.92
2.24
2.55
2.87
3.50
1.83
2.14
2.44
2.75
3.35
1.76
2.06
2.35
2.64
3.22
72
72
72
72
72
125
150
175
200
225
2.30
2.76
3.22
3.67
4.12
2.16
2.59
3.02
3.45
3.87
2.05
2.46
2.86
3.27
3.67
1.95
2.34
2.73
3.12
3.50
1.87
2.25
2.62
2.99
3.36
1.80
2.16
2.52
2.88
3.24
2.12
2.55
2.97
3.39
3.81
1.99
2.39
2.78
3.18
3.57
1.89
2.26
2.64
3.01
3.38
1.80
2.16
2.51
2.87
3.23
1.72
2.07
2.41
2.75
3.09
1.66
1.99
2.32
2.65
2.98
1.99
2.38
2.78
3.17
3.57
1.86
2.23
2.61
2.97
3.34
1.76
2.11
2.46
2.81
3.16
1.68
2.01
2.35
2.68
3.02
1.61
1.93
2.25
2.57
2.89
1.55
1.85
2.16
2.47
2.78
Nominal bearing increased to 80mm - See Section 6.1.11
67
Licensed copy: univulster, University of Ulster, 21/08/2017, Uncontrolled Copy, © TRADA Technology
Eurocode 5 span tables for solid timber members
Table 6.13 Permissible clear spans for single-span common or jack rafters
Slope of roof 22.5° or more but less than 30.0°
Strength Class C16
Imposed load
This table uses
target (= sawn) depth
qk = 1.02 kN/m² or Qk = 0.90 kN
Service Class 1 or 2
C16
Dead loads gk (kN/m²) excluding self-weight of rafter
Size of rafter
Breadth
Depth
(mm)
(mm)
Spacing of rafters (mm)
400
450
Maximum clear span (m)
gk not more than 0.5
gk not more than 0.75
gk not more than 1.00
600
400
450
600
400
450
600
38
38
38
38
100
125
150
195
1.78
2.38
3.00
4.14
1.75
2.34
2.95
4.05
1.68
2.24
2.80
3.71
1.68
2.24
2.80
3.82
1.65
2.19
2.74
3.73
1.57
2.07
2.58
3.44
1.61
2.12
2.64
3.59
1.57
2.07
2.58
3.49
1.49
1.95
2.41
3.24
44
44
44
44
100
125
150
195
1.90
2.54
3.19
4.38
1.87
2.50
3.13
4.27
1.80
2.38
2.97
3.89
1.80
2.38
2.97
4.05
1.76
2.33
2.91
3.94
1.68
2.20
2.73
3.62
1.71
2.26
2.81
3.80
1.68
2.20
2.73
3.69
1.58
2.07
2.56
3.41
100
125
150
195
1.96
2.61
3.28
4.49
1.93
2.57
3.22
4.37
1.85
2.45
3.05
3.98
1.85
2.45
3.05
4.15
1.82
2.40
2.98
4.05
1.73
2.26
2.81
3.70
1.76
2.32
2.88
3.90
1.73
2.26
2.81
3.79
1.63
2.13
2.63
3.48
114
140
184
2.12
2.75
3.86
2.08
2.70
3.78
1.99
2.57
3.50
1.99
2.57
3.57
1.95
2.52
3.49
1.85
2.37
3.25
1.89
2.43
3.36
1.85
2.37
3.27
1.74
2.23
3.04
47
47
47
47
ALS/CLS
38
38
38
Table 6.14 Permissible clear spans for single-span common or jack rafters
Slope of roof 22.5° or more but less than 30.0°
Strength Class C24
Imposed load
This table uses
target (= sawn) depth
qk = 1.02 kN/m² or Qk = 0.90 kN
Service Class 1 or 2
C24
Dead loads gk (kN/m²) excluding self-weight of rafter
Size of rafter
Breadth
Depth
(mm)
(mm)
Spacing of rafters (mm)
400
450
Maximum clear span (m)
gk not more than 0.5
gk not more than 0.75
gk not more than 1.00
600
400
450
600
400
450
600
38
38
38
38
100
125
150
195
2.06
2.74
3.44
4.70
2.03
2.69
3.37
4.53
1.94
2.56
3.19
4.13
1.94
2.56
3.19
4.34
1.90
2.51
3.12
4.22
1.81
2.37
2.93
3.84
1.85
2.42
3.01
4.06
1.81
2.37
2.93
3.95
1.70
2.22
2.74
3.61
44
44
44
44
100
125
150
195
2.20
2.92
3.65
4.93
2.16
2.86
3.57
4.75
2.07
2.72
3.35
4.33
2.07
2.72
3.39
4.58
2.03
2.66
3.31
4.43
1.92
2.51
3.10
4.03
1.97
2.57
3.19
4.29
1.92
2.51
3.11
4.17
1.81
2.36
2.90
3.80
100
125
150
195
2.26
3.00
3.74
5.04
2.22
2.94
3.67
4.85
2.13
2.80
3.42
4.42
2.13
2.80
3.47
4.69
2.08
2.74
3.39
4.53
1.98
2.58
3.18
4.12
2.02
2.64
3.27
4.40
1.98
2.58
3.19
4.27
1.86
2.42
2.97
3.88
114
140
184
2.44
3.16
4.39
2.40
3.10
4.28
2.29
2.94
3.90
2.29
2.94
4.06
2.24
2.87
3.95
2.12
2.70
3.62
2.17
2.77
3.81
2.12
2.71
3.70
1.99
2.53
3.41
47
47
47
47
ALS/CLS
38
38
38
68
Licensed copy: univulster, University of Ulster, 21/08/2017, Uncontrolled Copy, © TRADA Technology
6 Tables of sizes of pitched roof members
Table 6.15 Permissible clear spans for purlins supporting single-span rafters
Slope of roof 22.5° or more but less than 30.0°
This table uses
target (= sawn) depth
qk = 1.02 kN/m² or Qk = 0.90 kN
Service Class 1 or 2
Strength Class C16
C16
Imposed load
Dead loads gk (kN/m²) excluding self-weight of purlin
gk not more than 0.5
gk not more than 0.75
gk not more than 1.00
Size of
Spacing of purlins (mm)
purlin
B'dth D'pth 1500 1800 2100 2400 2700 3000 1500 1800 2100 2400 2700 3000 1500 1800 2100 2400 2700 3000
(mm) (mm) Maximum clear span (m)
63
63
63
63
63
150
175
200
225
275
2.18
2.54
2.90
3.26
3.98
1.99
2.31
2.64
2.97
3.63
1.83
2.14
2.44
2.75
3.35
1.71
2.00
2.28
2.56
3.13
1.61
1.88
2.14
2.41
2.94
1.52
1.78
2.03
2.28
2.78
2.02
2.36
2.69
3.03
3.70
1.84
2.15
2.45
2.76
3.37
1.70
1.98
2.27
2.55
3.11
1.59
1.85
2.11
2.38
2.90
1.49
1.74
1.99
2.23
2.73
1.41
1.64
1.88
2.11
2.58
1.90
2.21
2.53
2.84
3.47
1.73
2.01
2.30
2.58
3.16
1.59
1.86
2.12
2.39
2.91
1.48
1.73
1.98
2.22
2.72
1.39
1.63
1.86
2.09
2.55
1.32
1.54
1.76
1.97
2.41
72
72
72
72
72
125
150
175
200
225
1.97
2.33
2.72
3.10
3.49
1.81
2.13
2.48
2.83
3.18
1.67
1.96
2.29
2.62
1.56
1.83
2.14
2.44
1.47
1.73
2.01
2.30
1.39
1.63
1.90
2.17
1.68
1.97
2.30
2.63
1.55
1.82
2.13
2.43
1.44
1.70
1.98
2.27
1.36
1.60
1.87
2.13
1.29
1.51
1.76
2.02
1.45
1.71
1.99
2.27
1.35
1.59
1.86
2.12
1.27
1.50
1.75
1.99
1.20
1.42
1.65
1.89
2.75
2.58
2.45
2.95
2.73
2.55
2.40
2.27
1.72
2.03
2.37
2.70
3.04
1.57
1.85
2.16
2.46
2.94
1.83
2.17
2.53
2.88
3.24
2.77
2.56
2.39
2.24
2.12
Nominal bearing increased to 80mm - See Section 6.1.11
Table 6.16 Permissible clear spans for purlins supporting single-span rafters
This table uses
target (= sawn) depth
Slope of roof 22.5° or more but not more than 30.0° Imposed load qk = 1.02 kN/m² or Qk = 0.90 kN
Strength Class C24
C24
Service Class 1 or 2
Dead loads gk (kN/m²) excluding self-weight of purlin
gk not more than 0.5
gk not more than 0.75
gk not more than 1.00
Size of
Spacing of purlins (mm)
purlin
B'dth D'pth 1500 1800 2100 2400 2700 3000 1500 1800 2100 2400 2700 3000 1500 1800 2100 2400 2700 3000
(mm) (mm) Maximum clear span (m)
63
63
63
63
63
150
175
200
225
275
2.51
2.92
3.33
3.75
4.57
2.35
2.74
3.13
3.51
4.29
2.22
2.59
2.96
3.33
4.06
2.10
2.44
2.79
3.14
3.83
1.97
2.30
2.62
2.95
3.60
1.87
2.18
2.48
2.79
3.41
2.33
2.72
3.10
3.49
4.26
2.18
2.55
2.91
3.27
3.99
2.06
2.41
2.75
3.09
3.77
1.94
2.27
2.59
2.91
3.55
1.83
2.13
2.44
2.74
3.34
1.73
2.02
2.30
2.59
3.16
2.19
2.56
2.92
3.28
4.01
2.05
2.39
2.73
3.07
3.75
1.94
2.26
2.58
2.90
3.55
1.82
2.12
2.43
2.73
3.33
1.71
2.00
2.28
2.56
3.13
1.62
1.89
2.16
2.42
2.96
72
72
72
72
72
125
150
175
200
225
2.19
2.63
3.06
3.49
3.92
2.06
2.46
2.87
3.28
3.68
1.95
2.33
2.72
3.10
3.49
1.85
2.22
2.59
2.96
3.33
1.78
2.11
2.46
2.81
3.16
1.70
2.00
2.33
2.66
2.99
2.04
2.44
2.85
3.25
3.66
1.91
2.29
2.67
3.05
3.43
1.81
2.17
2.53
2.89
3.24
1.72
2.06
2.41
2.75
3.09
1.65
1.96
2.29
2.61
2.94
1.58
1.86
2.16
2.47
2.78
1.92
2.30
2.68
3.06
3.44
1.80
2.16
2.51
2.87
3.23
1.70
2.04
2.38
2.71
3.05
1.62
1.94
2.26
2.58
2.90
1.55
1.84
2.14
2.45
2.75
1.47
1.74
2.03
2.31
2.60
Nominal bearing increased to 80mm - See Section 6.1.11
69
Licensed copy: univulster, University of Ulster, 21/08/2017, Uncontrolled Copy, © TRADA Technology
Eurocode 5 span tables for solid timber members
Table 6.17 Permissible clear spans for single-span common or jack rafters
Slope of roof 30.0° or more but less than 45.0°
Strength Class C16
Imposed load
This table uses
target (= sawn) depth
qk = 0.60 kN/m² or Qk = 0.90 kN
Service Class 1 or 2
C16
Dead loads gk (kN/m²) excluding self-weight of rafter
Size of rafter
Breadth
Depth
(mm)
(mm)
Spacing of rafters (mm)
400
450
Maximum clear span (m)
gk not more than 0.5
gk not more than 0.75
gk not more than 1.00
600
400
450
600
400
450
600
38
38
38
38
100
125
150
195
1.83
2.45
3.09
4.25
1.81
2.41
3.03
4.16
1.73
2.30
2.88
3.93
1.73
2.30
2.88
3.93
1.70
2.25
2.81
3.83
1.62
2.13
2.65
3.58
1.65
2.18
2.72
3.68
1.62
2.13
2.65
3.58
1.53
2.00
2.48
3.34
44
44
44
44
100
125
150
195
1.96
2.62
3.28
4.50
1.93
2.57
3.22
4.40
1.85
2.45
3.06
4.15
1.85
2.45
3.06
4.15
1.82
2.40
2.98
4.05
1.73
2.26
2.81
3.79
1.76
2.32
2.88
3.90
1.73
2.26
2.81
3.79
1.63
2.13
2.63
3.53
100
125
150
195
2.02
2.69
3.37
4.62
1.99
2.64
3.31
4.51
1.91
2.52
3.14
4.26
1.91
2.52
3.14
4.26
1.87
2.46
3.06
4.15
1.78
2.33
2.88
3.89
1.81
2.38
2.96
4.00
1.78
2.33
2.88
3.89
1.68
2.18
2.70
3.62
114
140
184
2.18
2.83
3.97
2.14
2.78
3.88
2.05
2.65
3.67
2.05
2.65
3.67
2.01
2.59
3.58
1.90
2.44
3.35
1.95
2.50
3.45
1.90
2.44
3.35
1.79
2.29
3.13
47
47
47
47
ALS/CLS
38
38
38
Table 6.18 Permissible clear spans for single-span common or jack rafters
Slope of roof 30.0° or more but less than 45.0°
Strength Class C24
Imposed load
This table uses
target (= sawn) depth
qk = 0.60 kN/m² or Qk = 0.90 kN
Service Class 1 or 2
C24
Dead loads gk (kN/m²) excluding self-weight of rafter
Size of rafter
Breadth
Depth
(mm)
(mm)
Spacing of rafters (mm)
400
450
Maximum clear span (m)
gk not more than 0.5
gk not more than 0.75
gk not more than 1.00
600
400
450
600
400
450
600
38
38
38
38
100
125
150
195
2.12
2.82
3.53
4.83
2.09
2.77
3.46
4.72
2.00
2.63
3.28
4.45
2.00
2.63
3.28
4.45
1.96
2.58
3.20
4.34
1.86
2.43
3.01
4.06
1.90
2.49
3.09
4.17
1.86
2.43
3.01
4.06
1.75
2.28
2.81
3.77
44
44
44
44
100
125
150
195
2.26
3.00
3.75
5.10
2.22
2.94
3.67
4.99
2.13
2.80
3.48
4.69
2.13
2.80
3.48
4.70
2.08
2.74
3.39
4.58
1.98
2.58
3.19
4.28
2.02
2.64
3.27
4.41
1.98
2.58
3.19
4.28
1.86
2.42
2.98
3.98
100
125
150
195
2.33
3.08
3.85
5.23
2.29
3.02
3.77
5.11
2.19
2.87
3.57
4.79
2.19
2.87
3.57
4.82
2.14
2.81
3.48
4.69
2.03
2.65
3.27
4.39
2.08
2.72
3.36
4.51
2.03
2.65
3.27
4.39
1.91
2.48
3.05
4.08
114
140
184
2.51
3.25
4.51
2.47
3.18
4.41
2.35
3.02
4.16
2.35
3.02
4.16
2.30
2.95
4.06
2.18
2.78
3.80
2.23
2.85
3.91
2.18
2.78
3.80
2.05
2.60
3.54
47
47
47
47
ALS/CLS
38
38
38
70
Licensed copy: univulster, University of Ulster, 21/08/2017, Uncontrolled Copy, © TRADA Technology
6 Tables of sizes of pitched roof members
Table 6.19 Permissible clear spans for purlins supporting single-span rafters
This table uses
target (= sawn) depth
Slope of roof 30.0° or more but not more than 45.0° Imposed load qk = 0.60 kN/m² or Qk = 0.90 kN
Service Class 1 or 2
Strength Class C16
C16
Dead loads gk (kN/m²) excluding self-weight of purlin
gk not more than 0.5
gk not more than 0.75
gk not more than 1.00
Size of
Spacing of purlins (mm)
purlin
B'dth D'pth 1500 1800 2100 2400 2700 3000 1500 1800 2100 2400 2700 3000 1500 1800 2100 2400 2700 3000
(mm) (mm) Maximum clear span (m)
63
63
63
63
63
150
175
200
225
275
2.44
2.85
3.25
3.65
4.46
2.29
2.67
3.05
3.43
4.18
2.17
2.53
2.89
3.25
3.96
2.07
2.41
2.75
3.10
3.78
1.98
2.31
2.64
2.97
3.62
1.89
2.20
2.51
2.82
3.45
2.25
2.62
2.99
3.36
4.10
2.11
2.45
2.80
3.15
3.85
1.99
2.32
2.65
2.98
3.64
1.90
2.21
2.53
2.84
3.47
1.80
2.10
2.39
2.69
3.28
1.70
1.98
2.27
2.55
3.11
2.10
2.45
2.79
3.14
3.83
1.96
2.29
2.61
2.94
3.59
1.86
2.16
2.47
2.78
3.39
1.75
2.04
2.33
2.62
3.20
1.65
1.92
2.20
2.47
3.01
1.56
1.82
2.08
2.34
2.85
72
72
72
72
72
125
150
175
200
225
2.14
2.56
2.98
3.41
3.83
2.00
2.40
2.80
3.20
3.59
1.90
2.28
2.65
3.03
3.40
1.81
2.17
2.53
2.89
3.25
1.74
2.08
2.43
2.77
3.11
1.67
2.00
2.33
2.67
3.00
1.97
2.36
2.75
3.13
3.52
1.84
2.21
2.57
2.94
3.30
1.74
2.09
2.44
2.78
3.13
1.66
1.99
2.32
2.65
2.98
1.59
1.91
2.22
2.54
2.86
1.53
1.82
2.13
2.43
2.73
1.84
2.20
2.56
2.93
3.29
1.72
2.06
2.40
2.74
3.08
1.63
1.95
2.27
2.60
2.92
1.55
1.86
2.16
2.47
2.78
1.48
1.77
2.06
2.35
2.65
1.42
1.67
1.95
2.23
2.51
Nominal bearing increased to 80mm - See Section 6.1.11
Table 6.20 Permissible clear spans for purlins supporting single-span rafters
This table uses
target (= sawn) depth
Slope of roof 30.0° or more but not more than 45.0° Imposed load qk = 0.60 kN/m² or Qk = 0.90 kN
Strength Class C24
C24
Service Class 1 or 2
Dead loads gk (kN/m²) excluding self-weight of purlin
gk not more than 0.5
gk not more than 0.75
gk not more than 1.00
Size of
Spacing of purlins (mm)
purlin
B'dth D'pth 1500 1800 2100 2400 2700 3000 1500 1800 2100 2400 2700 3000 1500 1800 2100 2400 2700 3000
(mm) (mm) Maximum clear span (m)
63
63
63
63
63
150
175
200
225
275
2.72
3.17
3.62
4.07
4.96
2.55
2.98
3.40
3.82
4.66
2.42
2.82
3.22
3.62
4.42
2.31
2.69
3.07
3.45
4.21
2.21
2.58
2.95
3.31
4.04
2.13
2.48
2.84
3.19
3.89
2.51
2.92
3.33
3.75
4.57
2.35
2.74
3.13
3.52
4.29
2.22
2.59
2.96
3.33
4.06
2.12
2.47
2.82
3.17
3.87
2.03
2.37
2.70
3.04
3.71
1.95
2.28
2.60
2.92
3.57
2.34
2.73
3.12
3.50
4.27
2.19
2.56
2.92
3.28
4.01
2.08
2.42
2.76
3.11
3.79
1.98
2.30
2.63
2.96
3.61
1.89
2.21
2.52
2.83
3.46
1.82
2.12
2.42
2.72
3.33
72
72
72
72
72
125
150
175
200
225
2.38
2.85
3.32
3.79
4.25
2.23
2.68
3.12
3.56
4.00
2.12
2.54
2.96
3.37
3.79
2.02
2.42
2.82
3.22
3.62
1.94
2.32
2.71
3.09
3.47
1.86
2.23
2.61
2.98
3.34
2.19
2.62
3.06
3.49
3.92
2.05
2.46
2.87
3.28
3.68
1.95
2.33
2.72
3.10
3.49
1.85
2.22
2.59
2.96
3.33
1.78
2.13
2.48
2.84
3.19
1.71
2.05
2.39
2.73
3.07
2.05
2.45
2.86
3.27
3.67
1.92
2.30
2.68
3.06
3.44
1.82
2.18
2.54
2.90
3.26
1.73
2.08
2.42
2.76
3.11
1.66
1.99
2.32
2.65
2.98
1.59
1.91
2.23
2.55
2.86
Nominal bearing increased to 80mm - See Section 6.1.11
71
Licensed copy: univulster, University of Ulster, 21/08/2017, Uncontrolled Copy, © TRADA Technology
Eurocode 5 span tables for solid timber members
Table 6.21 Permissible clear spans for single-span common or jack rafters
Slope of roof 30.0° or more but less than 45.0°
Strength Class C16
Imposed load
This table uses
target (= sawn) depth
qk = 1.02 kN/m² or Qk = 0.90 kN
Service Class 1 or 2
C16
Dead loads gk (kN/m²) excluding self-weight of rafter
Size of rafter
Breadth
Depth
(mm)
(mm)
Spacing of rafters (mm)
400
450
Maximum clear span (m)
gk not more than 0.5
gk not more than 0.75
gk not more than 1.00
600
400
450
600
400
450
600
38
38
38
38
100
125
150
195
1.83
2.45
3.09
4.25
1.81
2.41
3.03
4.16
1.73
2.30
2.88
3.83
1.73
2.30
2.88
3.93
1.70
2.25
2.81
3.83
1.62
2.13
2.65
3.55
1.65
2.18
2.72
3.68
1.62
2.13
2.65
3.58
1.53
2.00
2.48
3.33
44
44
44
44
100
125
150
195
1.96
2.62
3.28
4.50
1.93
2.57
3.22
4.40
1.85
2.45
3.05
4.02
1.85
2.45
3.06
4.15
1.82
2.40
2.98
4.05
1.73
2.26
2.81
3.73
1.76
2.32
2.88
3.90
1.73
2.26
2.81
3.79
1.63
2.13
2.63
3.51
100
125
150
195
2.02
2.69
3.37
4.61
1.99
2.64
3.31
4.51
1.91
2.52
3.14
4.11
1.91
2.52
3.14
4.26
1.87
2.46
3.06
4.15
1.78
2.33
2.88
3.82
1.81
2.38
2.96
4.00
1.78
2.33
2.88
3.89
1.68
2.18
2.70
3.59
114
140
184
2.18
2.83
3.97
2.14
2.78
3.88
2.05
2.65
3.62
2.05
2.65
3.67
2.01
2.59
3.58
1.90
2.44
3.35
1.95
2.50
3.45
1.90
2.44
3.35
1.79
2.29
3.13
47
47
47
47
ALS/CLS
38
38
38
Table 6.22 Permissible clear spans for single-span common or jack rafters
Slope of roof 30.0° or more but less than 45.0°
Strength Class C24
Imposed load
This table uses
target (= sawn) depth
qk = 1.02 kN/m² or Qk = 0.90 kN
Service Class 1 or 2
C24
Dead loads gk (kN/m²) excluding self-weight of rafter
Size of rafter
Breadth
Depth
(mm)
(mm)
Spacing of rafters (mm)
400
450
Maximum clear span (m)
gk not more than 0.5
gk not more than 0.75
gk not more than 1.00
600
400
450
600
400
450
600
38
38
38
38
100
125
150
195
2.12
2.82
3.53
4.83
2.09
2.77
3.46
4.68
2.00
2.63
3.28
4.27
2.00
2.63
3.28
4.45
1.96
2.58
3.20
4.33
1.86
2.43
3.01
3.96
1.90
2.49
3.09
4.17
1.86
2.43
3.01
4.05
1.75
2.28
2.81
3.72
44
44
44
44
100
125
150
195
2.26
3.00
3.75
5.09
2.22
2.94
3.67
4.91
2.13
2.80
3.46
4.48
2.13
2.80
3.48
4.70
2.08
2.74
3.39
4.57
1.98
2.58
3.19
4.16
2.02
2.64
3.27
4.40
1.98
2.58
3.19
4.28
1.86
2.42
2.98
3.91
100
125
150
195
2.33
3.08
3.85
5.20
2.29
3.02
3.77
5.01
2.19
2.87
3.53
4.57
2.19
2.87
3.57
4.82
2.14
2.81
3.48
4.67
2.03
2.65
3.27
4.25
2.08
2.72
3.36
4.51
2.03
2.65
3.27
4.39
1.91
2.48
3.05
4.00
114
140
184
2.51
3.25
4.51
2.47
3.18
4.41
2.35
3.02
4.03
2.35
3.02
4.16
2.30
2.95
4.06
2.18
2.78
3.74
2.23
2.85
3.91
2.18
2.78
3.80
2.05
2.60
3.52
47
47
47
47
ALS/CLS
38
38
38
72
Licensed copy: univulster, University of Ulster, 21/08/2017, Uncontrolled Copy, © TRADA Technology
6 Tables of sizes of pitched roof members
Table 6.23 Permissible clear spans for purlins supporting single-span rafters
This table uses
target (= sawn) depth
Slope of roof 30.0° or more but not more than 45.0° Imposed load qk = 1.02 kN/m² or Qk = 0.90 kN
Strength Class C16
C16
Service Class 1 or 2
Dead loads gk (kN/m²) excluding self-weight of purlin
gk not more than 0.5
gk not more than 0.75
gk not more than 1.00
Size of
Spacing of purlins (mm)
purlin
B'dth D'pth 1500 1800 2100 2400 2700 3000 1500 1800 2100 2400 2700 3000 1500 1800 2100 2400 2700 3000
(mm) (mm) Maximum clear span (m)
63
63
63
63
63
150
175
200
225
275
2.30
2.68
3.06
3.44
4.20
2.10
2.44
2.79
3.14
3.83
1.94
2.26
2.58
2.90
3.54
1.81
2.11
2.41
2.71
3.31
1.70
1.98
2.27
2.55
3.11
1.61
1.88
2.14
2.41
2.94
2.13
2.49
2.84
3.19
3.89
1.94
2.26
2.59
2.91
3.55
1.79
2.09
2.39
2.68
3.28
1.67
1.95
2.23
2.51
3.06
1.57
1.83
2.09
2.36
2.88
1.49
1.73
1.98
2.23
2.72
1.99
2.32
2.65
2.98
3.64
1.82
2.12
2.42
2.72
3.32
1.68
1.95
2.23
2.51
3.06
1.56
1.82
2.08
2.34
2.86
1.47
1.71
1.96
2.20
2.69
1.39
1.62
1.85
2.08
2.54
72
72
72
72
72
125
150
175
200
225
2.03
2.44
2.84
3.24
3.65
1.91
2.25
2.62
2.99
3.36
1.76
2.08
2.42
2.76
3.11
1.65
1.94
2.26
2.58
2.90
1.55
1.82
2.13
2.43
2.73
1.47
1.73
2.01
2.30
2.59
1.89
2.26
2.64
3.01
3.39
1.77
2.08
2.42
2.77
3.11
1.63
1.92
2.24
2.56
2.88
1.52
1.79
2.09
2.39
2.68
1.43
1.69
1.97
2.25
2.53
1.36
1.60
1.86
2.13
2.39
1.77
2.13
2.48
2.83
3.18
1.65
1.94
2.27
2.59
2.91
1.53
1.8
2.09
2.39
2.69
1.42
1.68
1.95
2.23
2.51
1.34
1.58
1.84
2.10
2.36
1.27
1.49
1.74
1.98
2.23
Nominal bearing increased to 80mm - See Section 6.1.11
Table 6.24 Permissible clear spans for purlins supporting single-span rafters
This table uses
target (= sawn) depth
Slope of roof 30.0° or more but not more than 45.0° Imposed load qk = 1.02 kN/m² or Qk = 0.90 kN
Strength Class C24
C24
Service Class 1 or 2
Dead loads gk (kN/m²) excluding self-weight of purlin
gk not more than 0.5
gk not more than 0.75
gk not more than 1.00
Size of
Spacing of purlins (mm)
purlin
B'dth D'pth 1500 1800 2100 2400 2700 3000 1500 1800 2100 2400 2700 3000 1500 1800 2100 2400 2700 3000
(mm) (mm) Maximum clear span (m)
63
63
63
63
63
150
175
200
225
275
2.59
3.02
3.45
3.88
4.73
2.43
2.83
3.24
3.64
4.44
2.3
2.68
3.06
3.44
4.20
2.19
2.56
2.92
3.28
4.01
2.08
2.43
2.77
3.12
3.81
1.97
2.30
2.63
2.95
3.61
2.41
2.81
3.21
3.60
4.39
2.26
2.63
3.00
3.38
4.12
2.13
2.49
2.84
3.19
3.90
2.03
2.37
2.71
3.04
3.71
1.93
2.25
2.57
2.89
3.52
1.82
2.13
2.43
2.73
3.34
2.26
2.64
3.01
3.39
4.14
2.12
2.47
2.82
3.17
3.87
2.00
2.34
2.67
3.00
3.66
1.91
2.22
2.54
2.85
3.49
1.80
2.10
2.40
2.70
3.29
1.70
1.99
2.27
2.55
3.12
72
72
72
72
72
125
150
175
200
225
2.27
2.72
3.16
3.61
4.06
2.13
2.55
2.97
3.39
3.81
2.01
2.41
2.81
3.21
3.61
1.92
2.30
2.68
3.06
1.84
2.21
2.57
2.94
1.77
2.11
2.46
2.81
1.78
2.13
2.49
2.84
1.70
2.04
2.38
2.72
1.64
1.96
2.28
2.61
1.75
2.10
2.45
2.80
1.67
2.00
2.34
2.67
1.60
1.92
2.24
2.55
1.54
1.83
2.13
2.43
3.16
3.35
3.19
3.06
2.93
1.98
2.37
2.77
3.16
3.55
1.86
2.23
2.59
2.96
3.30
1.97
2.37
2.76
3.15
3.54
1.87
2.24
2.61
2.98
3.44
2.11
2.52
2.94
3.36
3.77
3.33
3.15
3.00
2.87
2.74
Nominal bearing increased to 80mm - See Section 6.1.11
73
Licensed copy: univulster, University of Ulster, 21/08/2017, Uncontrolled Copy, © TRADA Technology
Eurocode 5 span tables for solid timber members
6.2 Purlins supporting roof sheeting or decking
6.2.1
Tables 6.25 to 6.28 give permissible clear spans for 'canted' purlins supporting roof sheeting or decking
where the roof slope is from 10° to 30° inclusive.
6.2.2
Permissible clear spans have been calculated in accordance with EC5. Refer to Section 3.3.1 for
additional information on the method used.
6.2.3
The sizes, spacing and spans given will support the dead and imposed loads stated in the tables or a
concentrated load of 0.9 kN.
6.2.4
Lateral support should be provided. EC5 considers the stability of these members through the use of
a modification factor kcrit – assumed to be 1.0 throughout this book. In the absence of printed guidance
from the manufacturer, it should be assumed that expanded polyurethane and other low density
insulating materials will not provide such support. Therefore, with these materials, the depth to breadth
ratio of the purlins should not exceed 4:1.
6.2.5
Unless justified by specialist calculation, the minimum bearing length at supports for purlins should
be 60mm. It may sometimes be necessary to provide longer bearing for practical reasons. Where
longer bearing is required due to high bearing stresses in calculations, typically for larger sections, it is
indicated in the tables by shading where the bearing length should be increased to 80mm.
6.2.6
Notching or drilling of purlins should not be carried out unless justified by specialist calculation.
6.2.7
The section sizes of purlins given in Tables 6.25 to 6.28 should be sawn sections or be machined on
the width, ie reduce the depth of the binder to the tolerance classes specified in BS EN 336.
g
cin tres
a
sp en
n c
rli en
u
P twe
be
Cl
ea
rs
pa
Purlin
Sheeting
Support
Figure 6.2 Purlins supporting roof sheeting or decking
74
n
of
pu
rlin
Licensed copy: univulster, University of Ulster, 21/08/2017, Uncontrolled Copy, © TRADA Technology
6 Tables of sizes of pitched roof members
Table 6.25 P
ermissible clear spans for purlins supporting roof sheeting or
decking
qk = 0.60 kN/m² or Qk = 0.90 kN
Slope of roof 10° to 30°
Imposed load
Strength Class C16
Service Class 1 or 2
C16
This table uses
target (= sawn) depth
Dead loads gk (kN/m²) excluding self-weight of purlin
gk not more than 0.25
gk not more than 0.50
gk not more than 0.75
Size of
Spacing of purlins (mm)
purlin
B'dth D'pth 900 1200 1500 1800 2100 2400 900 1200 1500 1800 2100 2400 900 1200 1500 1800 2100 2400
(mm) (mm) Maximum clear span (m)
44
44
44
44
44
44
100
125
150
175
200
225
1.82
2.43
2.98
3.46
3.95
4.43
1.74
2.25
2.70
3.14
3.59
4.03
1.67
2.09
2.50
2.91
3.32
3.73
1.57
1.96
2.35
2.73
3.12
3.51
1.48
1.85
2.22
2.59
2.95
3.32
1.41
1.76
2.07
2.42
2.76
3.10
1.63
2.14
2.66
3.11
3.55
3.98
1.54
2.01
2.42
2.82
3.21
3.61
1.47
1.86
2.23
2.60
2.97
3.34
1.40
1.75
2.09
2.44
2.79
3.13
1.32
1.65
1.96
2.28
2.61
2.93
1.26
1.55
1.83
2.13
2.44
2.74
1.50
1.96
2.42
2.86
3.27
3.67
1.41
1.83
2.22
2.59
2.95
3.32
1.33
1.71
2.05
2.39
2.73
3.07
1.27
1.60
1.92
2.24
2.55
2.87
1.21
1.50
1.77
2.07
2.36
2.65
1.15
1.40
1.65
1.93
2.20
2.47
47
47
47
47
47
47
100
125
150
175
200
225
1.87
2.50
3.04
3.54
4.04
4.53
1.80
2.31
2.76
3.22
3.67
4.12
1.71
2.13
2.56
2.98
3.40
3.82
1.60
2.00
2.40
2.80
3.19
3.59
1.52
1.90
2.27
2.65
3.03
3.40
1.45
1.81
2.14
2.50
2.85
3.21
1.68
2.20
2.73
3.18
3.63
4.07
1.58
2.06
2.47
2.88
3.29
3.70
1.51
1.91
2.29
2.67
3.04
3.42
1.43
1.79
2.14
2.50
2.85
3.21
1.35
1.69
2.03
2.36
2.70
3.03
1.29
1.61
1.89
2.21
2.52
2.83
1.54
2.01
2.48
2.93
3.34
3.75
1.45
1.88
2.27
2.65
3.02
3.40
1.37
1.75
2.10
2.45
2.79
3.14
1.31
1.64
1.96
2.29
2.62
2.94
1.24
1.55
1.83
2.14
2.44
2.74
1.18
1.45
1.71
1.99
2.28
2.56
63
63
63
63
63
63
100
125
150
175
200
225
2.13
2.80
3.35
3.90
4.44
4.98
2.04
2.55
3.05
3.55
4.04
4.54
1.89
2.36
2.83
3.29
3.76
4.22
1.78
2.22
2.66
3.10
3.53
3.97
1.68
2.10
2.52
2.94
3.35
3.76
1.61
2.01
2.41
2.80
3.20
3.59
1.90
2.48
3.01
3.51
4.00
4.49
1.79
2.28
2.74
3.19
3.63
4.08
1.69
2.11
2.53
2.95
3.37
3.78
1.59
1.98
2.38
2.77
3.16
3.55
1.50
1.88
2.25
2.63
3.00
3.37
1.43
1.79
2.15
2.50
2.86
3.21
1.75
2.27
2.78
3.23
3.69
4.14
1.63
2.10
2.52
2.93
3.35
3.76
1.55
1.94
2.33
2.71
3.10
3.48
1.46
1.82
2.18
2.55
2.91
3.27
1.38
1.72
2.07
2.41
2.75
3.09
1.31
1.64
1.97
2.29
2.62
2.95
Nominal bearing increased to 80mm - See Section 6.2.5
75
Licensed copy: univulster, University of Ulster, 21/08/2017, Uncontrolled Copy, © TRADA Technology
Eurocode 5 span tables for solid timber members
Table 6.26 P
ermissible clear spans for purlins supporting roof sheeting or
decking
qk = 0.60 kN/m² or Qk = 0.90 kN
Slope of roof 10° to 30°
Imposed load
Strength Class C24
Service Class 1 or 2
C24
This table uses
target (= sawn) depth
Dead loads gk (kN/m²) excluding self-weight of purlin
gk not more than 0.25
gk not more than 0.50
gk not more than 0.75
Size of
Spacing of purlins (mm)
purlin
B'dth D'pth 900 1200 1500 1800 2100 2400 900 1200 1500 1800 2100 2400 900 1200 1500 1800 2100 2400
(mm) (mm) Maximum clear span (m)
44
44
44
44
44
44
100
125
150
175
200
225
2.10
2.77
3.31
3.86
4.40
4.93
2.01
2.51
3.01
3.50
4.00
4.49
1.87
2.33
2.79
3.25
3.71
4.17
1.75
2.19
2.62
3.05
3.48
3.91
1.66
2.07
2.48
2.89
3.30
3.71
1.58
1.98
2.37
2.76
3.15
3.54
1.87
2.44
2.98
3.47
3.95
4.44
1.76
2.25
2.70
3.14
3.59
4.03
1.67
2.08
2.50
2.91
3.32
3.73
1.56
1.95
2.34
2.73
3.12
3.50
1.48
1.85
2.22
2.58
2.95
3.32
1.41
1.76
2.11
2.46
2.81
3.16
1.72
2.23
2.74
3.19
3.64
4.09
1.61
2.07
2.48
2.89
3.30
3.71
1.52
1.91
2.29
2.67
3.05
3.43
1.43
1.79
2.15
2.50
2.86
3.21
1.36
1.69
2.03
2.37
2.70
3.04
1.29
1.61
1.93
2.25
2.57
2.89
47
47
47
47
47
47
100
125
150
175
200
225
2.16
2.83
3.39
3.94
4.49
5.04
2.06
2.57
3.08
3.58
4.09
4.59
1.91
2.38
2.85
3.32
3.79
4.26
1.79
2.24
2.68
3.12
3.56
4.00
1.70
2.12
2.54
2.96
3.38
3.80
1.62
2.02
2.42
2.83
3.23
3.63
1.92
2.51
3.04
3.54
4.04
4.54
1.81
2.30
2.76
3.22
3.67
4.12
1.71
2.13
2.56
2.98
3.40
3.82
1.60
2.00
2.40
2.79
3.19
3.58
1.52
1.89
2.27
2.65
3.02
3.40
1.44
1.80
2.16
2.52
2.88
3.24
1.77
2.29
2.80
3.27
3.73
4.19
1.65
2.12
2.54
2.96
3.38
3.79
1.56
1.96
2.35
2.74
3.12
3.51
1.47
1.83
2.20
2.56
2.93
3.29
1.39
1.74
2.08
2.43
2.77
3.11
1.32
1.65
1.98
2.31
2.64
2.97
63
63
63
63
63
63
100
125
150
175
200
225
2.45
3.12
3.73
4.33
4.93
5.53
2.27
2.83
3.39
3.95
4.50
5.05
2.11
2.63
3.15
3.67
4.18
4.70
1.98
2.47
2.96
3.45
3.94
4.42
1.88
2.35
2.81
3.28
3.74
4.20
1.80
2.24
2.69
3.13
3.57
4.01
2.17
2.80
3.36
3.90
4.45
4.99
2.04
2.55
3.05
3.55
4.05
4.55
1.89
2.36
2.83
3.29
3.76
4.22
1.78
2.22
2.66
3.09
3.53
3.97
1.68
2.10
2.52
2.93
3.35
3.76
1.60
2.00
2.40
2.80
3.20
3.59
1.99
2.57
3.10
3.60
4.11
4.61
1.86
2.34
2.81
3.27
3.73
4.19
1.74
2.17
2.60
3.03
3.46
3.89
1.63
2.04
2.44
2.84
3.25
3.65
1.54
1.93
2.31
2.69
3.08
3.46
1.47
1.84
2.20
2.57
2.93
3.30
Nominal bearing increased to 80mm - See Section 6.2.5
76
Licensed copy: univulster, University of Ulster, 21/08/2017, Uncontrolled Copy, © TRADA Technology
6 Tables of sizes of pitched roof members
Table 6.27 P
ermissible clear spans for purlins supporting roof sheeting or
decking
qk = 1.02 kN/m² or Qk = 0.90 kN
Slope of roof 10° to 30°
Imposed load
Strength Class C16
Service Class 1 or 2
C16
This table uses
target (= sawn) depth
Dead loads gk (kN/m²) excluding self-weight of purlin
gk not more than 0.25
gk not more than 0.50
gk not more than 0.75
Size of
Spacing of purlins (mm)
purlin
B'dth D'pth 900 1200 1500 1800 2100 2400 900 1200 1500 1800 2100 2400 900 1200 1500 1800 2100 2400
(mm) (mm) Maximum clear span (m)
44
44
44
44
44
44
100
125
150
175
200
225
1.82
2.31
2.77
3.22
3.68
4.13
1.67
2.03
2.39
2.79
3.18
3.58
1.49
1.82
2.14
2.49
2.85
3.20
1.35
1.65
1.95
2.27
2.59
2.91
1.25
1.53
1.80
2.10
2.39
2.69
1.17
1.43
1.68
1.96
2.23
2.51
1.63
2.11
2.53
2.94
3.36
3.78
1.53
1.87
2.20
2.56
2.93
3.29
1.36
1.67
1.96
2.29
2.61
2.94
1.24
1.52
1.79
2.08
2.38
2.67
1.15
1.40
1.65
1.92
2.19
2.47
1.07
1.30
1.54
1.79
2.05
2.30
1.50
1.96
2.35
2.74
3.12
3.51
1.40
1.74
2.04
2.38
2.72
3.06
1.27
1.55
1.82
2.12
2.43
2.73
1.15
1.41
1.66
1.93
2.21
2.48
1.06
1.30
1.53
1.78
2.04
2.29
0.99
1.21
1.42
1.66
1.90
2.13
47
47
47
47
47
47
100
125
150
175
200
225
1.87
2.37
2.83
3.30
3.76
4.23
1.72
2.10
2.48
2.88
3.29
3.70
1.54
1.88
2.21
2.58
2.94
3.31
1.40
1.71
2.01
2.35
2.68
3.01
1.29
1.58
1.86
2.17
2.48
2.79
1.21
1.47
1.74
2.02
2.31
2.60
1.68
2.16
2.59
3.01
3.44
3.86
1.56
1.93
2.27
2.65
3.02
3.40
1.41
1.72
2.03
2.37
2.70
3.04
1.28
1.57
1.85
2.15
2.46
2.77
1.19
1.45
1.71
1.99
2.27
2.55
1.11
1.35
1.59
1.86
2.12
2.38
1.54
2.01
2.40
2.80
3.20
3.59
1.44
1.80
2.11
2.46
2.81
3.16
1.31
1.60
1.88
2.20
2.51
2.82
1.19
1.46
1.72
2.00
2.28
2.57
1.10
1.34
1.58
1.85
2.11
2.37
1.02
1.25
1.47
1.72
1.96
2.21
63
63
63
63
63
63
100
125
150
175
200
225
2.10
2.61
3.13
3.64
4.15
4.65
1.90
2.37
2.84
3.31
3.77
4.23
1.76
2.18
2.56
2.99
3.41
3.83
1.63
1.99
2.34
2.73
3.11
3.50
1.50
1.84
2.16
2.52
2.88
3.23
1.40
1.72
2.02
2.35
2.69
3.02
1.90
2.39
2.86
3.33
3.80
4.26
1.73
2.16
2.59
3.02
3.44
3.87
1.60
2.00
2.36
2.74
3.13
3.52
1.49
1.82
2.15
2.50
2.86
3.21
1.38
1.69
1.98
2.31
2.64
2.97
1.29
1.57
1.85
2.16
2.47
2.77
1.75
2.22
2.66
3.10
3.54
3.97
1.61
2.01
2.41
2.81
3.20
3.60
1.49
1.86
2.19
2.55
2.91
3.27
1.39
1.69
2.00
2.33
2.66
2.98
1.28
1.57
1.84
2.15
2.45
2.76
1.20
1.46
1.72
2.01
2.29
2.57
Nominal bearing increased to 80mm - See Section 6.2.5
77
Licensed copy: univulster, University of Ulster, 21/08/2017, Uncontrolled Copy, © TRADA Technology
Eurocode 5 span tables for solid timber members
Table 6.28 P
ermissible clear spans for purlins supporting roof sheeting or
decking
qk = 1.02 kN/m² or Qk = 0.90 kN
Slope of roof 10° to 30°
Imposed load
Strength Class C24
Service Class 1 or 2
C24
This table uses
target (= sawn) depth
Dead loads gk (kN/m²) excluding self-weight of purlin
gk not more than 0.25
gk not more than 0.50
gk not more than 0.75
Size of
Spacing of purlins (mm)
purlin
B'dth D'pth 900 1200 1500 1800 2100 2400 900 1200 1500 1800 2100 2400 900 1200 1500 1800 2100 2400
(mm) (mm) Maximum clear span (m)
44
44
44
44
44
44
100
125
150
175
200
225
2.07
2.58
3.09
3.60
4.10
4.60
1.87
2.34
2.80
3.26
3.72
4.18
1.73
2.16
2.59
3.02
3.45
3.87
1.62
2.03
2.39
2.78
3.18
3.57
1.54
1.87
2.21
2.57
2.94
3.30
1.43
1.75
2.06
2.40
2.74
3.08
1.87
2.35
2.82
3.29
3.75
4.21
1.71
2.13
2.55
2.97
3.40
3.82
1.58
1.97
2.36
2.75
3.14
3.53
1.48
1.84
2.19
2.56
2.92
3.28
1.39
1.72
2.02
2.36
2.69
3.03
1.31
1.60
1.89
2.20
2.51
2.83
1.72
2.19
2.62
3.06
3.49
3.92
1.58
1.98
2.37
2.76
3.16
3.55
1.46
1.83
2.19
2.55
2.91
3.28
1.37
1.71
2.03
2.37
2.71
3.05
1.29
1.59
1.88
2.19
2.50
2.81
1.22
1.49
1.75
2.04
2.33
2.62
47
47
47
47
47
47
100
125
150
175
200
225
2.11
2.64
3.16
3.68
4.19
4.71
1.92
2.39
2.86
3.34
3.81
4.27
1.77
2.21
2.65
3.09
3.53
3.96
1.66
2.08
2.47
2.88
3.29
3.70
1.57
1.94
2.28
2.66
3.04
3.42
1.48
1.81
2.13
2.49
2.84
3.19
1.92
2.41
2.88
3.36
3.83
4.31
1.75
2.18
2.61
3.04
3.47
3.90
1.61
2.02
2.42
2.82
3.21
3.61
1.51
1.89
2.26
2.64
3.01
3.39
1.43
1.78
2.09
2.44
2.79
3.13
1.36
1.66
1.95
2.28
2.60
2.93
1.76
2.24
2.68
3.13
3.57
4.01
1.62
2.02
2.43
2.83
3.23
3.63
1.50
1.87
2.24
2.61
2.98
3.35
1.40
1.75
2.10
2.45
2.79
3.14
1.32
1.65
1.94
2.27
2.59
2.91
1.26
1.54
1.81
2.11
2.41
2.71
63
63
63
63
63
63
100
125
150
175
200
225
2.33
2.91
3.48
4.05
4.61
5.18
2.12
2.64
3.16
3.68
4.20
4.71
1.96
2.45
2.93
3.42
3.90
4.38
1.84
2.30
2.76
3.21
3.66
4.11
1.75
2.18
2.61
3.04
3.47
3.90
1.67
2.08
2.48
2.89
3.30
3.71
2.13
2.66
3.18
3.71
4.23
4.75
1.93
2.41
2.89
3.37
3.84
4.31
1.79
2.23
2.68
3.12
3.56
4.00
1.68
2.10
2.51
2.93
3.34
3.75
1.59
1.98
2.38
2.77
3.16
3.56
1.51
1.89
2.27
2.64
3.02
3.39
1.99
2.48
2.97
3.46
3.94
4.43
1.80
2.24
2.69
3.13
3.58
4.02
1.66
2.08
2.49
2.90
3.31
3.72
1.56
1.95
2.33
2.72
3.10
3.49
1.47
1.84
2.21
2.57
2.94
3.30
1.40
1.75
2.10
2.45
2.80
3.15
Nominal bearing increased to 80mm - See Section 6.2.5
78