SUPPLEMENT
Structural-Use
Panels
LRFD
LOAD AND RESISTANCE FACTOR DESIGN
MANUAL FOR ENGINEERED
WOOD CONSTRUCTION
SUPPLEMENT
Structural-Use
Panels
LRFD
LOAD AND RESISTANCE FACTOR DESIGN
MANUAL FOR ENGINEERED
WOOD CONSTRUCTION
Copyright © 1996
APA – The Engineered Wood Association
Preface
This supplement contains adjustment factors, dimensions, factored resistance, reference strengths and other
properties required to design structural-use panels in the
LRFD format. In this format, the term “resistance” is
used to refer to member capacities (i.e., moment resistance, compression resistance, etc.). This is distinct from
the term “strength” which refers to limit state material
properties — conceptually a “factored allowable stress.”
The member resistance values tabulated in this
s u p p l e m e n t are to be used in conjunction with the
design methodologies provided in AF&PA/ASCE 16-95, Standard for Load and Resistance Factor Design (LRFD)
for Engineered Wood Construction.
The reference strengths were derived according to
the principles of ASTM D5457-93, Standard Specification for Computing the Reference Resistance of
Wood-based Materials and Structural Connections for
Load and Resistance Factor Design.
The tabulated reference strength values are to be used
within the reference end-use conditions defined therein.
When the end-use conditions fall outside the range of the
reference conditions, the reference values shall be adjusted
by the product of applicable adjustment factors as defined
in AF&PA/ASCE 16-95 and also provided in this supplement. For unusual end-use conditions, the designer should
consult additional literature for possible further adjustments.
APA/EWS
TABLE OF CONTENTS
Chapter/Title
Page
1. Designer Flowchart
..................................................
1
...................................................................................
3
1.1 Flowchart
2. Introduction
Chapter/Title
5. Factored Reference
Resistance ................................................................................... 15
5.1 General
5.2 Capacity Selection Tables
5.3 Factored Reference Shear Resistances
for Shear Walls and Diaphragms
2.1 Products Description
2.2 Typical Applications
2.3 Availability
3. Reference Strength and
Stiffness ................................................................................................. 7
6. Other Considerations
6.1
6.2
6.3
6.4
3.1 Derivation of Reference Values
3.2 Example Derivation
4. Design Adjustment Factors
4.1
4.2
4.3
4.4
4.5
4.6
4.7
.......
11
General
Grade and Construction Factor, CG
Width Factor, Cw
Moisture Effect Factor, CM
Temperature Factor, Ct
Preservative Treatment Factor, Cpt
Fire Retardant Treatment Factor, Crt
Page
..................................
21
Fastening (Nailing) Schedules
Panel Spacing
Panel Edge Support
Panel Specification
7. Supplemental Design
Assistance ................................................................................... 25
7.1 General
7.2 Load-Span Tables
7.3 Design Example
8. Section Properties
..............................................
39
8.1 General
8.2 Section and Weight Properties
LIST OF TABLES
2.1 Typical Panel Constructions
4.1 Moisture Effect Factor, CM
...............................................................
.............................................................
4.2 Grade and Construction Factors, CG
...................................
6
12
14
5.1 Baseline Flexural Capacities .......................................................... 16
5.2 Baseline Shear Capacities
................................................................
17
5.3 Baseline Axial Capacities .................................................................. 17
5.4 Factored Shear Resistance (kip/ft) for
Structural-Use Panel Shear Walls with Framing
of Douglas-fir, Larch, or Southern Pine for
Wind or Seismic Loading .................................................................... 18
5.5 Factored Shear Resistance (kip/ft) for
Structural-Use Panel Horizontal Diaphragms
with Framing of Douglas-fir, Larch, or
Southern Pine for Wind or Seismic Loading .............. 19
6.1 Minimum Nailing Recommendations for StructuralUse Panel Applications ........................................................................ 22
6.2 Panel Edge Support ................................................................................... 23
7.1 Baseline Uniform Load Capacities (psf) ........................ 27
7.2 OSB Uniform Load Capacities (psf)
..................................
29
7.3 5-Ply Plywood Uniform Load Capacities (psf) ...... 32
7.4 4-Ply Plywood Uniform Load Capacities (psf) ...... 34
7.5 3-Ply Plywood Uniform Load Capacities (psf) ...... 35
7.6 COM-PLY Uniform Load Capacities (psf) ................ 36
8.1 Panel Section and Weight Properties .................................. 40
8.2 Relationship Between Span Rating and
Nominal Thickness ..................................................................................... 40
APA/EWS
APA/EWS
LRFD STRUCTURAL-USE PANELS SUPPLEMENT
1
1
DESIGNER
FLOWCHART
1.1
Flowchart
2
APA/EWS
2
DESIGNER FLOWCHART
1.1 Flowchart
Structural-Use Panel
Supplement
No
Select Trial Panel (b)
End-Use
Conditions
Consistent With
Reference
Conditions (a) ?
No
Yes
Load-Span
Criteria Satisfied ?
(Section 7.2)
Yes
Determine B a s eline
Capacities (Section 5.2)
Use Load-Span Tables
(Section 7.2)
Determine Design
Capacities (c)
Factored Strengths >
Factored Load Effects ?
No
No
Factored Strengths >
Factored Load Effects ?
Yes
Yes
No
Design Stiffness >
Unfactored Load Effects ?
Yes
(a)
(b)
(c)
Design Stiffness >
Unfactored Load Effects ?
Accept Trial Panel
Yes
See Section 4.
As a starting point, it is suggested to satisfy stiffness requirements first using load-span tables.
Apply end-use and grade-construction factors given in Section 4.
APA/EWS
No
LRFD STRUCTURAL-USE PANELS SUPPLEMENT
3
2
INTRODUCTION
2.1
Products Description
4
2.2
Typical Applications
5
2.3
Availability
5
Table 2.1 Typical Panel Constructions .................................. 6
APA/EWS
4
INTRODUCTION
2.1 Products Description
Structural-Use Panels
ber preceding the slash is the maximum recommended
support spacing for roof applications. The number following the slash is the maximum recommended support
spacing for subfloor applications. For example, a panel
rated as 24/16 may be applied as roof sheathing over
supports spaced 24 inches o.c. or as subfloor over supports spaced 16 inches o.c. Recommendations for use
of sheathing panels also include wall applications.
Structural-use panels are wood-based panel products that
have been rated for use in structural applications. Common applications for structural-use panels include roof
sheathing, wall sheathing, subflooring, and single-layer
flooring (combination subfloor-underlayment).
Structural-use panels are classified by span ratings.
Panel span ratings identify the maximum recommended
support spacings for specific end uses. Design capacities
are provided on the basis of span ratings.
Structural-use panel recommendations provided in this
supplement are applicable to panels manufactured in accordance with the provisions of PS1 and / or PS2.
Designer must specify structural-use panels by the
span ratings, nominal thickness, grade and construction
associated with tabulated design recommendations. Exposure durability classification must also be identified.
Certain of the roof sheathing spans are dependent upon
panel edge support (see Section 6.3).
Sheathing panels rated for use only as wall sheathing
are usually identified as either Wall-24 or Wall-16. The
numerical index (24 or 16) corresponds to the maximum wall stud spacing. Wall sheathing panels are
performance tested with the secondary axis spanning
across supports. For this reason, wall sheathing panels
may be applied with either the primary or secondary
axis across supports.
Panel Grades
Based on PS2 (see Section 6.4), structural-use panel
grade names include Sheathing, Single Floor, and Structural I Sheathing Corresponding grade names in PS1 are
C-D, Underlayment, and Structural I C-D.
• Single Floor: The Single Floor span rating is an index
number that provides the maximum recommended support spacing with the primary axis across two or more
supports. Typical Single Floor span ratings are 20 oc
and 24 oc, although 16 oc, 32 oc, and 48 oc Single Floor
panels are also available.
• Sheathing grade panels are rated for use in subfloor,
roof, and wall applications.
Single Floor panels may also carry a dual trademark,
for which the second span index covers applications
with the secondary axis across supports. Such panels
are typically used in flooring systems of manufactured
housing.
• Single Floor panels are rated for use as combination
subfloor-underlayment and are usually manufactured
with tongue and groove (T&G) edge profiles.
• Single Floor panels are typically sanded or touch-sanded
while Sheathing panels are usually unsanded.
• Structural I Sheathing panels meet the requirements of
the sheathing grade as well as additional requirements
associated with use in panelized roof systems, diaphragms, and shear walls.
Panel Constructions
• Plywood: Plywood is comprised of alternating layers
Span Ratings
Span ratings indicate the maximum recommended
support spacing, in inches, for specific applications. The
span rating system applies when the panel is applied with
the reference axis across two or more supports. The reference axis is usually the primary axis of the panel.
• Sheathing: Sheathing panels rated for use in roof or
subfloor applications are identified with a dual span
index — two numbers separated by a slash. The num-
APA/EWS
of veneer (plies). Each layer consists of one or more
plies. Structural-use plywood panels are assembled with
waterproof adhesive applied between plies. The adhesive cures upon application of heat and pressure.
Plywood has been manufactured since the early 1930’s
and was the original structural-use panel. Plywood panels were originally manufactured from Douglas-fir logs.
Presently a variety of domestic species are used in plywood manufacture. Due to continued strong demand
for forest products, along with artificial constraints on
wood supply, imported species are becoming a factor
in domestic plywood production.
LRFD STRUCTURAL-USE
PANELS SUPPLEMENT
GUIDELINE
TO LRFD FOR STRUCTURAL
COMPOSITE LUMBER
the two remaining core layers are comprised of wood
fiber sandwiched between the veneer layers. COM-PLY
panels are manufactured with waterproof adhesives.
COM-PLY was developed as a cooperative effort of
the U.S. Forest Service and APA to more efficiently
utilize the wood resource.
• Oriented Strand Board: Oriented strand board (OSB)
Exposure Durability
The following exposure durability classifications are
based on product composition and adhesive bond durability.
• Exterior: Exterior panels may be used in applications
Oriented strand board is manufactured from hardwood
species, softwood species, and mixed species. The hardwood species used are selectively harvested from forests
that naturally regenerate. The softwood resource is derived from fast-maturing species from managed forests.
Much of the softwood resource represents selective
harvesting from these managed forests.
• COM-PLY®: COM-PLY panels are composite panels
of wood veneer and other wood-based material. COM-PLY
panels are typically manufactured with five layers. The
outer layers and the center layer are wood veneer, and
that are permanently exposed to the weather or to moisture.
• Exposure 1: Exposure 1 panels may be used in applications that are not permanently exposed to weather or
moisture, but where resistance to moisture effects due
to high humidity, water leakage, exposure during construction delays, or similar exposure conditions, is
required.
• Exposure 2: Exposure 2 panels may be used for interior applications requiring resistance to effects of high
humidity and water leakage.
2.2 Typical Applications
Panel Applications
Shear Walls and Diaphragms
In addition to roof, subfloor, wall, and single-layer
floor applications, structural-use panels are used in other
applications. Such applications include structural-insulated
panels, I-joist webs, materials handling systems (pallets,
bins, crating), transportation equipment, and concrete
forming.
Structural-use panels are used as components of wall,
floor, and roof systems to resist and transfer in-plane forces
as may be imposed by wind or seismic loading. Shear walls
and diaphragms represent an important application for
structural-use panels.
2.3 Availability
Although other panel constructions may be available,
Table 2.1 shows constructions most typically manufactured. Check with suppliers concerning availability.
APA/EWS
2
INTRODUCTION
is comprised of thin rectangular wood strands arranged
in a minimum of three cross-aligned layers and bonded
under heat and pressure with a waterproof and boilproof adhesive. OSB’s predecessor product was
waferboard, a wood panel product that was first commercially produced in the mid-1960’s. Waferboard
manufacture involved a mat-formed panel product with
random distribution of rectangular wafers. Oriented
strand board, a significantly improved structural panel
compared to waferboard, was first produced in the early
1980’s.
5
5
6
INTRODUCTION
Table 2.1 Typical Panel Constructions(a)
Span Rating
3-ply
24/0
24/16
32/16
40/20
48/24
✔
16 oc
20 oc
24 oc
32 oc
48 oc
(a)
(b)
✔
✔
Plywood
4-ply
5-ply(b)
SHEATHING
COM-PLY
✔
✔
✔
✔
✔
✔
✔
✔
✔
✔
✔
SINGLE FLOOR
✔
✔
✔
✔
✔
✔
✔
✔
✔
✔
Constructions listed may not be available in every area. Check with suppliers concerning availability.
Applies to plywood with 5 or more layers.
APA/EWS
OSB
✔
✔
✔
✔
✔
LRFD STRUCTURAL-USE PANELS SUPPLEMENT
7
REFERENCE
STRENGTH AND
STIFFNESS
3
3.1
Derivation of Reference Values
8
3.2
Example Derivation
8
APA/EWS
8
REFERENCE STRENGTH AND STIFFNESS
3.1 Derivation of Reference Values
Reference resistance values (load capacities), such as
those provided in Tables 5.1, 5.2, and 5.3, will serve the
majority of panel design requirements. When necessary,
design strength and stiffness (elastic modulus) may be
derived from tabulated resistance on the basis of the sec-
tion properties provided in Table 8.1. For this purpose,
the appropriate section properties for each span rating are
identified in Table 8.1.
Note that tabulated reference resistance values given
in Tables 5.1 through 5.5 are factored.
3.2 Example Derivation
Example Statement
Reference Modulus of Elasticity, E
Derive reference strength and stiffness (elastic modulus) for 15/32-inch 5-ply Structural I Sheathing 32/16
applied with the primary axis across supports. Design
conditions correspond with reference end-use conditions
given in Section 2.5 of AF&PA/ASCE 16-95, Standard
for Load and Resistance Factor Design (LRFD) for Engineered Wood Construction.
E = (EI) ÷ I
As
EI = 115 kip-in.2/ft
4
I = 0.103 in. /ft
∴
(Table 5.1)
(Table 8.1)
E = 115 ÷ 0.103 = 1117 ksi
Design Strength and Stiffness
Reference Properties
The reference property is derived by dividing the
baseline capacity by the appropriate section property, and
applicable time effect and resistance factors.
In general, design strength and stiffness are determined
by adjusting reference properties with grade-construction
factors and end-use adjustment factors.
FN = F (CG) (C)
Reference Bending Strength, Fb
where:
FN = Design Strength
Fb = (λφbM) ÷ (λφbS)
As
F = Reference Strength
λφbM = 0.639 kip-in./ft
∴
(Table 5.1)
λ = 0.8, φb = 0.85
(Table 5.1)
S = 0.440 in.3/ft
(Table 8.1)
Fb = 0.639 ÷ [(0.8) (0.85) (0.440)] = 2.14 ksi
Reference Planar Shear Strength, Fs
Fs = (λφvVs) ÷ [λφv (Ib / Q)]
As
λφvVs = 0.363 kip/ft
(Table 5.2)
λ = 0.8, φv = 0.75
(Table 5.2)
2
Ib/Q = 3.75 in. /ft
∴
CG = Grade-Construction Factor (Table 4.2)
C = Product of End-Use Adjustment Factors
For this example, design conditions correspond with
reference end-use conditions, so that the product of enduse adjustment factors, C, is unity. The grade-construction
factors for 5-ply Structural I Sheathing 32/16 are taken
from Table 4.2. The capacity factor applies to the derived
strength. For example, CG for moment capacity (M) applies for reference bending strength (Fb).
Design Bending Strength, FbN
(Table 8.1)
Fs = 0.363 ÷ [(0.8) (0.75) (3.75)] = 0.161 ksi
FbN = (Fb) (CG) (C)
= (2.14) (1.2) (1.0)
= 2.57 ksi
APA/EWS
LRFD STRUCTURAL-USE
PANELS SUPPLEMENT
GUIDELINE
TO LRFD FOR STRUCTURAL
COMPOSITE LUMBER
Design Planar Shear Strength, FsN
9
9
Design Modulus of Elasticity, EN
FsN = (Fs) (CG) (C)
EN = (E) (CG) (C)
= (0.161) (1.6) (1.0)
= (1117) (1.1) (1.0)
= 0.258 ksi
= 1229 ksi
3
REFERENCE STRENGTH AND STIFFNESS
APA/EWS
10
REFERENCE STRENGTH AND STIFFNESS
APA/EWS
LRFD STRUCTURAL-USE PANELS SUPPLEMENT
11
DESIGN
ADJUSTMENT
FACTORS
4
4.1
General
12
4.2
Grade and Construction Factor, CG
12
4.3
Width Factor, Cw
12
4.4
Moisture Effect Factor, CM
12
4.5
Temperature Factor, Ct
13
4.6
Preservative Treatment Factor, Cpt
13
4.7
Fire Retardant Treatment Factor, Crt
13
Table 4.1 Moisture Effect Factor, CM .................................. 12
Table 4.2 Grade and Construction Factors, CG ................... 14
APA/EWS
12
DESIGN ADJUSTMENT FACTORS
4.1 General
Panel design capacities are determined by multiplying baseline capacities, as given in Tables 5.1, 5.2, and
5.3, by the grade-construction factor, CG, appropriate for
each specific product. Baseline capacities represent the
minimum of each capacity (moment, shear, stiffness,...)
for each grade and span rating. Grade-construction factors are provided in Section 4.2.
Tabulated capacities provided in this document are
suitable for reference end-use conditions (see Section 2.5
of AF&PA/ASCE 16-95). Reference end-use conditions
are consistent with conditions typically associated with
light-frame construction. For structural-use panels, these
typical conditions involve the use of full-size untreated
panels in moderate temperature and moisture exposures.
Appropriate adjustment factors are provided for applications in which the conditions of use are inconsistent
with reference conditions. In addition to temperature and
moisture, this includes consideration of panel treatment
and size effects. Reference conditions and adjustment
factors are provided in Sections 4.3 through 4.7.
The tabulated adjustment factors are based on data
from tests of panels bearing the APA trademark.
4.2 Grade and Construction Factor, CG
Reference capacities presented in Tables 5.1, 5.2, and
5.3 of this document represent minimum values for each
listed grade and construction. Table 4.2 provides adjustments to the minimum capacities as appropriate for specific
constructions and grades.
Note that the capacities given in Tables 5.4 and 5.5 of
this document for shear walls and diaphragms have taken
the effect of grade and construction into account. Thus,
the grade and construction factor shall be taken as unity
(CG = 1.0).
4.3 Width Factor, Cw
Reference capacities given in Tables 5.1, and 5.3 of
this document for bending and tension are applicable for
panels 24 inches or greater in width. For panel widths, b,
greater than or equal to 8 inches and less than 24 inches,
the following width effect factor, Cw, shall be applied to
reference capacities for bending and tension:
Note that this factor is not applicable to the capacities
given in Tables 5.4 and 5.5 of this document for shear
walls and diaphragms. Narrow-width shear walls require
special design considerations which are beyond the scope
of this document.
For 8 in. ≤ b < 24 in., Cw = (8 + b) / 32
4.4 Moisture Effect Factor, CM
When the equilibrium moisture content of structuraluse panels is expected to be 16% or greater in service, the
moisture effect factor, CM, shall be applied to reference
capacities given in Tables 5.1 through 5.5 of this document.
Table 4.1 Moisture Effect Factor, CM
Reference Capacity
Strength
Stiffness
CM
0.75
0.85
APA/EWS
LRFD STRUCTURAL-USE PANELS SUPPLEMENT
13
4.5 Temperature Factor, Ct
The temperature effect factor, Ct, shall be applied when
structural-use panels are exposed to in-service sustained
temperatures. In the range of 100 to 200ºF, the temperature effect factor is applicable only when moisture content
of structural-use panels at the elevated temperature can
be expected to remain at 16% or greater for wet-use (moisture content 16% or greater) conditions, or at 12% or above
for dry-use conditions (moisture content below 16%). The
temperature effect factor shall be computed according to
the following equation:
Ct = 1.0 - αt (T - 100)
where:
αt = Temperature effect coefficient = 0.005 for
structural-use panels
T = Temperature (°F)
This factor is applicable to the capacities given in
Tables 5.1 through 5.5 of this document.
Capacities given in Tables 5.1 through 5.5 apply without adjustment (C pt = 1.0) to plywood pressure
impregnated with preservative chemicals and redried in
accordance with American Wood Preservers Association
(AWPA) Specification C-9 or Specification C-22. How-
ever, due to the absence of applicable treating industry
standards, OSB and COM-PLY panels are not currently
recommended for applications requiring pressure-preservative treating.
4.7 Fire Retardant Treatment Factor, Crt
The information provided in this document does not
apply to fire-retardant-treated panels. All capacities and
end-use conditions for fire-retardant-treated panels shall
be in accordance with the recommendations of the company providing the treating and redrying service.
APA/EWS
DESIGN ADJUSTMENT FACTORS
4.6 Preservative Treatment Factor, Cpt
4
14
DESIGN ADJUSTMENT FACTORS
Table 4.2 Grade and Construction Factors(a), CG
Strength Axis
Grade
M
Primary
Structural I
Other(b)
Structural I
Other(b)
1.0
1.0
1.3
1.0
Structural I
Other(b)
Structural I
Other(b)
1.1
1.1
1.7
1.2
Structural I
Other(b)
Structural I
Other(b)
1.2
1.2
2.8
1.8
Structural I
Other(b)
Structural I
Other(b)
1.2
1.2
2.8
1.8
Structural I
Other(b)
Structural I
Other(b)
1.2
1.2
1.7
1.2
Secondary
Primary
Secondary
Primary
Secondary
Primary
Secondary
Primary
Secondary
(a)
(b)
(c)
(d)
EI
Vs
3-Ply Plywood
1.1
1.4
1.1
1.0
1.5
5.2
1.0
2.8
4-Ply Plywood(c)
1.1
1.4
1.1
1.0
3.3
7.9
2.2
3.9
5-Ply Plywood(d)
1.1
1.6
1.1
1.1
5.2
1.4
3.1
1.0
OSB
1.0
1.0
1.0
1.0
5.2
1.0
3.1
1.0
COM-PLY
1.1
1.0
1.1
1.0
3.3
1.0
2.2
1.0
Vv
Gvt
T
P
EA
1.3
1.0
1.3
1.0
1.3
1.0
1.3
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.7
1.3
1.7
1.3
1.7
1.3
1.7
1.3
1.0
1.0
1.0
1.0
1.5
1.5
1.5
1.5
1.0
1.0
1.0
1.0
2.0
1.5
2.0
1.5
1.7
1.5
1.7
1.5
1.3
1.3
1.3
1.3
1.5
1.5
1.5
1.5
1.0
1.0
1.0
1.0
2.9
2.9
2.9
2.9
3.1
3.1
3.1
3.1
1.0
1.0
1.3
1.3
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.7
1.3
1.7
1.3
1.7
1.3
1.7
1.3
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
M = Moment resistance, EI = Flexural stiffness, Vs = Planar (Rolling) shear resistance, Vv = Through-thickness shear resistance, Gvt = Shear rigidity, T = Tension
resistance, P = Compression resistance, and EA = Axial stiffness.
Sheathing and Single Floor.
Factors for 4-ply also apply to plywood with 5 plys/3 layers.
Factors apply to plywood with 5 or more layers.
APA/EWS
LRFD STRUCTURAL-USE PANELS SUPPLEMENT
15
FACTORED
REFERENCE
RESISTANCE
5
5.1
General
16
5.2
Capacity Selection Tables
16
5.3
Factored Reference Shear Resistances
for Shear Walls and Diaphragms
18
Table 5.1 Baseline Flexural Capacities ................................ 16
Table 5.2 Baseline Shear Capacities ..................................... 17
Table 5.3 Baseline Axial Capacities ..................................... 17
Table 5.4 Factored Shear Resistance (kip/ft) for
Structural-Use Panel Shear Wallswith
Framing of Douglas-fir, Larch, or Southern
Pine for Wind or Seismic Loading ...................... 18
Table 5.5 Factored Shear Resistance (kip/ft) for
Structural-Use Panel Horizontal Diaphragms
with Framing of Douglas-fir, Larch, or
Southern Pine for Wind or Seismic Loading ...... 19
APA/EWS
16
FACTORED REFERENCE RESISTANCE
5.1 General
The capacities provided in Tables 5.1 through 5.5 are
based on data from tests of panels bearing the APA trademark.
Factored baseline capacities are provided in Table 5.1
through Table 5.3. Factored reference shear resistances
for structural-use panel shear walls (vertical diaphragms)
and horizontal diaphragms are given in Tables 5.4 and
5.5, respectively, for wind and seismic loading.
5.2 Capacity Selection Tables
Factored capacities are provided in Table 5.1 through
Table 5.3. The tabulated capacities represent baseline
capacities. The minimum of each specific capacity (moment, shear, stiffness,...) from the various grades and span
ratings was used to establish the capacity baseline. All
structural-use panels referenced in this Supplement meet
or exceed the baseline. For design, factored baseline capacities shall be adjusted by appropriate grade-construction
factors and end-use adjustment factors (see Section 4 of
this Supplement) to provide factored design capacities.
Table 5.1 Baseline Flexural Capacities(a,b)
Span Rating
Axis
24/0
24/16
32/16
40/20
48/24
16 oc
20 oc
24 oc
32 oc
48 oc
(a)
(b)
Factored Moment Resistance
λφbM (kip-in./ft)
Primary
Secondary
SHEATHING
0.432
0.093
0.553
0.111
0.639
0.159
1.080
0.259
1.460
0.389
SINGLE FLOOR
0.717
0.173
0.829
0.242
1.106
0.372
1.503
0.657
2.765
1.175
Unfactored Flexural Stiffness
EI (kip-in.2/ft)
Primary
Secondary
60.00
78.00
115.0
225.0
400.0
150.0
210.0
300.0
650.0
1150
3.600
5.200
8.100
18.00
29.50
11.00
13.00
26.00
75.00
160.0
λ = 0.80 and φb = 0.85. For λ other than 0.80, the tabulated value should be divided by 0.80 and then multiplied by the appropriate λ.
For design purposes, the tabulated value shall be multiplied by a grade-construction factor (CG) given in Section 4.2 and other applicable adjustment factors given
in Section 4.
APA/EWS
LRFD STRUCTURAL-USE
PANELS SUPPLEMENT
GUIDELINE
TO LRFD FOR STRUCTURAL
COMPOSITE LUMBER
17
17
Table 5.2 Baseline Shear Capacities(a,b)
Span Rating
Axis
(b)
24/0
24/16
32/16
40/20
48/24
0.285
0.328
0.363
0.458
0.588
0.181
0.181
0.225
0.285
0.328
16 oc
20 oc
24 oc
32 oc
48 oc
0.389
0.458
0.588
0.691
1.037
0.251
0.294
0.337
0.484
0.778
Factored Through-Thickness
Shear Resistance
λφvVv (kip/ft)
Primary
Secondary
SHEATHING
0.092
0.098
0.107
0.118
0.130
SINGLE FLOOR
0.100
0.116
0.128
0.145
0.181
Unfactored Shear Rigidity
Gvtv (kip/in.)
Primary
Secondary
0.092
0.098
0.107
0.118
0.130
25.00
27.00
27.00
28.50
31.00
25.00
27.00
27.00
28.50
31.00
0.100
0.116
0.128
0.145
0.181
27.00
28.00
30.00
36.00
50.50
27.00
28.00
30.00
36.00
50.50
λ = 0.80 and φv = 0.75. For λ other than 0.80, the tabulated value should be divided by 0.80 and then multiplied by the appropriate λ.
For design purposes, the tabulated value shall be multiplied by a grade-construction factor (CG) given in Section 4.2 and other applicable adjustment factors given
in Section 4.
Table 5.3 Baseline Axial Capacities(a,b)
Span Rating
Axis
(a)
(b)
Factored Tension Resistance
λφtT (kip/ft)
Primary
Secondary
24/0
24/16
32/16
40/20
48/24
3.974
4.493
4.838
5.011
6.912
1.037
1.711
2.160
2.765
3.370
16 oc
20 oc
24 oc
32 oc
48 oc
4.493
5.011
5.789
6.912
9.677
2.506
2.765
3.370
4.320
8.640
Factored Compression
Resistance
λφcP (kip/ft)
Primary
Secondary
SHEATHING
4.925
5.616
6.134
7.258
8.640
SINGLE FLOOR
6.912
7.258
8.640
10.886
22.464
Unfactored Axial Stiffness
EA (kip/ft)
Primary
Secondary
4.320
4.320
5.357
6.912
8.294
3350
3800
4150
5000
5850
2900
2900
3600
4600
5000
6.221
6.912
8.294
10.714
21.600
4500
5000
5850
7500
15000
4200
4600
5000
7300
14600
λ = 0.80, φt = 0.80, and φc = 0.90. For λ other than 0.80, the tabulated value should be divided by 0.80 and then multiplied by the appropriate λ.
For design purposes, the tabulated value shall be multiplied by a grade-construction factor (CG) given in Section 4.2 and other applicable adjustment factors
given in Section 4.
APA/EWS
5
FACTORED REFERENCE RESISTANCE
(a)
Factored Planar (Rolling)
Shear Resistance
λφvVs (kip/ft)
Primary
Secondary
18
FACTORED REFERENCE RESISTANCE
5.3 Factored Reference Shear Resistances for Shear
Walls and Diaphragms
Tables 5.4 and 5.5 give factored reference shear resistances for structural-use panel shear walls (vertical
diaphragms) and horizontal diaphragms for wind and seismic loading. These resistances were developed through
format conversion from Allowable Stress Design (ASD)
to Load and Resistance Factor Design (LRFD).
A factor of 1.3 was used to convert the allowable shear
forces for shear walls and diaphragms to the LRFD factored reference shear resistances. This factor is the same
as the load factor specified for wind design cases in
AF&PA/ASCE 16-95. Note that the ASD shear capaciTable 5.4
Panel Grade
STRUCTURAL I
SHEATHING
SHEATHING
(a)
(b)
(c)
ties for shear walls and diaphragms were based on shortterm loading (i.e., no adjustments for load duration are
necessary when using the ASD tables for shear walls and
diaphragms), which is consistent with the referenced time
effect in the LRFD.
Given the fact that panel shear walls and diaphragms
have performed well under seismic loading in the past
when designed in accordance with ASCE 7-88, and the
difference in the load effect for seismic loading between
ASCE 7-88 and ASCE 7-93 is limited, Tables 5.4 and 5.5
are considered applicable to seismic loading as well.
Factored(a) Shear Resistance (kip/ft) for Structural-Use Panel Shear
Walls with Framing of Douglas-fir, Larch, or Southern Pine(b) for Wind
or Seismic Loading(c)
Minimum
Nominal Panel
Thickness
(in.)
5/16
3/8
7/16
15/32
15/32
5/16 or 1/4
3/8
3/8
7/16
15/32
15/32
19/32
Minimum Nail
Penetration in
Framing
(in.)
1-1/4
1-1/2
1-5/8
1-1/4
1-1/2
1-5/8
Panels Applied Direct to Framing
Nail Size
(Common or
Nail spacing at panel edges (in.)
Galv. Box)
6
4
3
2(e)
6d
0.26
0.39
0.51
0.66
0.30(d)
0.47(d)
0.60(d)
0.79(d)
8d
0.33(d)
0.51(d)
0.66(d)
0.87(d)
0.36
0.56
0.72
0.95
10d(f)
0.44
0.66
0.86
1.13
6d
0.23
0.35
0.46
0.59
0.26
0.39
0.51
0.66
0.29(d)
0.42(d)
0.53(d)
0.69(d)
8d
0.31(d)
0.46(d)
0.59(d)
0.76(d)
0.34
0.49
0.64
0.83
10d(d)
0.40
0.60
0.78
1.00
0.44
0.66
0.86
1.13
λ = 1.0, φz = 0.65
For framing of other species: (1) Find specific gravity for species of lumber
in the AF&PA National Design Specification, (2) for common or galvanized
box nails, find shear value from table for nail size for STRUCTURAL I
panels (regardless of actual grade); for galvanized casing nails, take shear
value directly from table, (3) multiply this value by 0.82 for species with
specific gravity greater than or equal to 0.42 but less than 0.49, or multiply
by 0.65 for species with specific gravity less than 0.42.
All panel edges backed with 2-in. nominal or wider framing. Install panels
either horizontally or vertically. Space nails 6 in. o.c. along intermediate
framing members for 3/8-in. and 7/16-in. panels installed on studs spaced
24 in. o.c. For other conditions and panel thicknesses, space nails 12 in.
o.c. on intermediate supports.
(d)
(e)
(f)
APA/EWS
Panels Applied Over 1/2" or 5/8" Gypsum Sheathing
Nail Size
(Common or
Nail spacing at panel edges (in.)
Galv. Box)
6
4
3
2(e)
8d
0.26
0.39
0.51
0.66
0.36
0.56
0.72
0.95
10d
0.36
0.56
0.72
0.95
0.36
0.56
0.72
0.95
-----8d
0.23
0.35
0.46
0.59
0.26
0.39
0.51
0.66
0.34
0.49
0.64
0.83
10d(f)
0.34
0.49
0.64
0.83
0.34
0.49
0.64
0.83
-----------
Shears are permitted to be increased to values shown for 15/32-in. sheathing with same nailing, provided (1) studs are spaced a maximum of 16 in.
o.c. or (2) if panels are applied with long dimension across studs.
Framing at adjoining panel edges shall be 3-in. nominal or wider, and nails
shall be staggered where nails are spaced 2 in. o.c.
Framing at adjoining panel edges shall be 3-in. nominal or wider, and nails
shall be staggered where 10d nails having penetration into framing of more
than 1-5/8 in. are spaced 3 in. o.c.
LRFD STRUCTURAL-USE
PANELS SUPPLEMENT
GUIDELINE
TO LRFD FOR STRUCTURAL
COMPOSITE LUMBER
Table 5.5
Panel Grade
STRUCTURAL I
SHEATHING
Factored(a) Shear Resistance (kip/ft) for Structural-Use Panel
Horizontal Diaphragms with Framing of Douglas-fir, Larch, or
Southern Pine(b) for Wind or Seismic Loading
Common
Nail
Size
6d(f)
Minimum
Nail
Penetration
in Framing
(in.)
1-1/4
Minimum
Nominal
Panel
Thickness
(in.)
5/16
8d
1-1/2
3/8
10d(e)
1-5/8
15/32
6d(f)
1-1/4
5/16
SHEATHING
AND
3/8
SINGLE FLOOR
8d
1-1/2
7/16
15/32
15/32
10d(e)
1-5/8
19/32
(b)
(c)
Minimum
Nominal
Width of
Framing
Member
(in.)
2
3
2
3
2
3
2
3
2
3
2
3
2
3
2
3
2
3
2
3
Blocked Diaphragms(c)
Nail Spacing (in.) at Diaphragm Boundaries (all
cases), at Continuous Panel Edges Parallel to Load
(Cases 3 & 4), and at All Panel Edges (Cases 5 & 6)
6
4
2-1/2(d)
2(d)
Nail spacing (in.) at other panel edges
(Cases 1, 2, 3 & 4)
6
6
4
3
0.24
0.33
0.49
0.55
0.27
0.36
0.55
0.62
0.35
0.47
0.69
0.78
0.39
0.52
0.78
0.88
0.42
0.55
0.83
0.95
0.47
0.62
0.94
1.07
0.22
0.29
0.44
0.49
0.25
0.33
0.49
0.56
0.24
0.33
0.49
0.55
0.27
0.36
0.55
0.62
0.31
0.42
0.62
0.71
0.35
0.47
0.70
0.79
0.33
0.44
0.66
0.75
0.37
0.49
0.74
0.84
0.35
0.47
0.69
0.78
0.39
0.52
0.78
0.88
0.38
0.50
0.75
0.85
0.42
0.56
0.85
0.96
0.42
0.55
0.83
0.95
0.47
0.62
0.94
1.07
λ = 1.0, φz = 0.65
For framing of other species: (1) Find specific gravity for species of lumber
in the AF&PA National Design Specification, (2) for common or galvanized
box nails, find shear value from table for nail size for STRUCTURAL I
panels (regardless of actual grade); for galvanized casing nails, take shear
value directly from table, (3) multiply this value by 0.82 for species with
specific gravity greater than or equal to 0.42 but less than 0.49, or multiply
by 0.65 for species with specific gravity less than 0.42.
Space nails maximum 12 in. o.c. along intermediate framing members (6
in. o.c. when supports are spaced 48 in. o.c.).
(d)
Unblocked Diaphragms
Nail Spaced 6 in. Maximum at Supported
Edges(c)
Case 1
All other
(No unblocked edges or
configurations
continuous joints parallel
(Cases 2, 3, 4,
to load)
5 & 6)
0.21
0.16
0.24
0.18
0.31
0.23
0.34
0.26
0.37
0.28
0.42
0.31
0.20
0.14
0.22
0.16
0.21
0.16
0.24
0.18
0.28
0.21
0.31
0.23
0.30
0.22
0.33
0.25
0.31
0.23
0.34
0.26
0.33
0.25
0.38
0.28
0.37
0.28
0.42
0.31
Framing at adjoining panel edges shall be 3-in. nominal or wider, and nails
shall be staggered where nails are spaced 2 or 2-1/2 in. o.c.
(e)
Framing at adjoining panel edges shall be 3-in. nominal or wider, and nails
shall be staggered where 10d nails having penetration into framing of more
than 1-5/8 in. are spaced 3 in. o.c.
(f)
8d is recommended minimum for roofs due to negative pressures of high
winds.
Notes: Design for diaphragm stresses depends on direction of continuous panel
joints with reference to load, not on direction of long dimension of sheet.
Continuous framing may be in either direction for blocked diaphragms.
APA/EWS
5
FACTORED REFERENCE RESISTANCE
3/8
a)
19
19
20
FACTORED REFERENCE RESISTANCE
APA/EWS
LRFD STRUCTURAL-USE PANELS SUPPLEMENT
21
OTHER
CONSIDERATIONS
6.1
Fastening (Nailing) Schedules
22
6.2
Panel Spacing
22
6.3
Panel Edge Support
22
6.4
Panel Specification
23
Table 6.1 Minimum Nailing Recommendations for
Structural-Use Panel Applications ....................... 22
Table 6.2 Panel Edge Support ............................................... 23
APA/EWS
6
22
OTHER CONSIDERATIONS
6.1 Fastening (Nailing) Schedules
Table 6.1
Minimum Nailing Recommendations for Structural-Use Panel
Applications
Application
SINGLE FLOOR--Glue-nailed installation
16, 20, 24 oc, 3/4-in. thick or less
24 oc, 7/8-in. or 1-in. thick
32, 48 oc, 32-in. span (c-c)
48 oc, 48-in. span (c-c)
SINGLE FLOOR--Nailed-only installation
16, 20, 24 oc, 3/4-in. thick or less
24 oc, 7/8-in. or 1-in. thick
32, 48 oc, 32-in. span
48 oc, 48-in. span
SHEATHING--Subflooring
7/16-in. to 1/2-in. thick
7/8-in. thick or less
Thicker panels
SHEATHING--Wall sheathing
1/2-in. thick or less
Over 1/2-in. thick
SHEATHING--Roof sheathing
5/16-in. to 1-in. thick
Thicker panels
(a)
(b)
(c)
(d)
Recommended
Nail Size & Type
Ring- or screw-shank
6d(a)
8d(a)
8d(a)
8d(b)
Ring- or screw-shank
6d
8d
8d(b)
8d(b)
Common smooth, ring- or screw-shank(c)
6d
8d
10d
Common smooth, ring- or screw-shank or
galvanized box(c)
6d
8d
Common smooth, ring- or screw-shank(c)
8d
8d ring- or screw-shank
or 10d common smooth
Nail Spacing (in.)
Panel
Intermediate
Edges
Supports
12
6
6
6
12
12
12
6
6
6
6
6
12
12
12
6
6
6
6
12
12
6
6
6
12
12
6
6
12(d)
12(d)
8d common nails may be substituted if ring- or screw-shank nails are not available.
10d ring-shank, screw-shank, or common nails may be substituted if supports are well seasoned.
Other code-approved fasteners may be used.
For spans 48 in. or greater, space nails 6 in. at all supports.
6.2 Panel Spacing
Wood-based panel products expand and contract
slightly as a natural response to changes in panel moisture content. To provide for in-plane dimensional changes,
panels should be installed with a 1/8-inch spacing at all
panel end and edge joints. A standard 10d box nail may
be used to check panel edge and panel end spacing.
6.3 Panel Edge Support
For certain span ratings, the maximum recommended
roof span for sheathing panels is dependent upon panel
edge support. Although edge support may be provided
by lumber blocking, panel clips are typically used when
edge support is required. Table 6.2 summarizes the relationship between panel edge support and maximum
recommended spans.
APA/EWS
LRFD STRUCTURAL-USE
PANELS SUPPLEMENT
GUIDELINE
TO LRFD FOR STRUCTURAL
COMPOSITE LUMBER
Table 6.2
23
23
Panel Edge Support
Sheathing
Span rating
24/0
24/16
32/16
40/20
48/24
(a)
Maximum Recommended Span (in.)
With Edge Support
Without Edge Support
24
20(a)
24
24
32
28
40
32
48
36
20 in. for 3/8-in., 24 in. for 15/32-in. and 1/2-in. panels.
6.4 Panel Specification
General
References — Structural-Use
Panels
A partial listing of references for further information
on structural-use panels and panel applications follows.
Additional information is available from organizations
providing trademarking and quality assurance services.
APA - The Engineered Wood Association
7011 South 19th Street
Tacoma, Washington 98466-5399
U.S.A.
Phone: (206) 565-6600
Fax: (206) 565-7265
Structural Board Association
45 Sheppard Avenue East, Suite 412,
Willowdale, Ontario M2N 5W9
CANADA
Phone: (416) 730-9090
Fax: (416) 730-9013
Publications
• U.S. Product Standard PS1 — Construction and Industrial Plywood
• U.S. Product Standard PS2 — Performance Standard
for Wood-Based Structural-Use Panels
• Grades & Specifications
• Panel Handbook & Grade Glossary
• Residential & Commercial Design/Construction Guide
• Diaphragms Design/Construction Guide
• Fire Rated Systems Design/Construction Guide
Publication
• OSB in Wood Frame Construction — U.S. Edition
• Design Rated OSB Design Manual — Canadian Codes
APA/EWS
6
OTHER CONSIDERATIONS
Structural-use panel recommendations provided in this
design supplement are applicable to PS1 and PS2 panels.
Design recommendations are based on structural capacities associated with specific panel classifications.
Structural-use panels are classified by span ratings.
Designers must specify structural-use panels by the
span ratings, nominal thicknesses, grades, and constructions associated with tabulated design recommendations.
Exposure durability classification must also be identified.
Single Floor panels may have tongue-and-groove or
square edges. If square edge Single Floor panels are speci-
fied, the specification shall require lumber blocking between supports.
Further information regarding specification of structural-use panels is provided in the following references.
24
OTHER CONSIDERATIONS
APA/EWS
LRFD STRUCTURAL-USE PANELS SUPPLEMENT
25
SUPPLEMENTAL
DESIGN
ASSISTANCE
7.1
General
26
7.2
Load-Span Tables
26
7.3
Design Example
38
Table 7.1 Baseline Uniform Load Capacities (psf) ............ 27
Table 7.2 OSB Uniform Load Capacities (psf) ................... 29
Table 7.3 5-Ply Plywood Uniform Load Capacities (psf) ... 32
Table 7.4 4-Ply Plywood Uniform Load Capacities (psf) ... 34
Table 7.5 3-Ply Plywood Uniform Load Capacities (psf) ... 35
Table 7.6 COM-PLY Uniform Load Capacities (psf) ......... 36
APA/EWS
7
26
SUPPLEMENTAL DESIGN ASSISTANCE
7.1 General
This section provides maximum load-span tables for
structural-use panels under uniform loading. Baseline
load-span tables are provided prior to the constructionspecific (OSB, plywood, COM-PLY) load-span tables.
The construction-specific load-span tables provide uniform load capacities for panel constructions that are
generally available.
The “baseline” load-span tables will allow designers
to quickly identify potential span rating(s) that may satisfy design requirements. The baseline load-span tables
were determined on the basis of baseline capacities (Section 5) which are based on testing of APA trademarked
structural-use panels.
When structural-use panels are applied with the primary axis across supports, three spans are assumed if
supports are spaced 32 inches o.c. or less. Two spans are
assumed when support spacing is greater than 32 inches
o.c.
When structural-use panels are applied with the secondary axis across supports, three spans are assumed for
support spacings of 16 inches o.c. or less. Two spans are
assumed if support spacings are greater than 16 inches
o.c. and less than or equal to 24 inches o.c.
One-span applications are not covered in the load-span
tables. Nominal 2-inch supports were assumed for spans
less than 48 inches, and nominal 4-inch supports were
assumed for 48-inch spans.
7.2 Load-Span Tables
Where:
Load-span tables provided in this section are suitable
for use when the design end-use conditions are consistent
with reference end-use conditions (see Section 4.1). The
following load-span tables were generated with an assumed dead load of 10 psf for shear and moment limit
states. Deflection-limited uniform loads apply in general,
as loads are not factored in deflection design.
Uniform loads limited by strength capacities (moment,
shear) satisfy the following expression:
λ = Time Effect Factor
φ = Resistance Factor
RN = Design Resistance
D = Dead Load Effect
L = Live Load Effect (roof live, floor live, or snow)
Design resistances, time effect factor, and resistance
factors were taken from Section 5.2 of this Supplement.
The tabulated uniform loads are not rounded.
λφRN ≥ 1.2D + 1.6L
APA/EWS
LRFD STRUCTURAL-USE
PANELS SUPPLEMENT
GUIDELINE
TO LRFD FOR STRUCTURAL
COMPOSITE LUMBER
Table 7.1
Baseline Uniform Load Capacities(a,b,c) (psf)
Limit
State
12
16
24/0
L/360
L/240
L/180
M
Vs
L/360
L/240
L/180
M
Vs
L/360
L/240
L/180
M
Vs
L/360
L/240
L/180
M
Vs
L/360
L/240
L/180
M
Vs
234
351
468
228
342
304
456
608
291
393
448
672
896
336
435
877
1315
1754
565
548
1559
2338
3118
763
702
91
136
181
129
248
118
177
235
165
286
174
260
347
190
315
339
509
679
319
397
604
905
1207
430
509
32/16
40/20
48/24
Primary Axis Across Supports
Span (in., center-to-center)
19.2
24
32
SHEATHING
50
25
10
75
37
15
100
49
20
90
59
34
204
161
119
65
32
13
98
48
19
131
64
26
115
75
43
234
185
137
96
47
19
144
71
29
193
95
38
133
86
49
259
204
151
188
93
37
283
139
56
377
185
75
222
143
82
326
257
190
335
164
67
502
247
100
670
329
133
300
193
109
417
329
243
APA/EWS
40
48
Secondary Axis Across Supports
Span (in., center-to-center)
12
16
19.2
24
12
15
19
100
15
23
30
31
126
27
40
54
41
161
14
21
28
51
219
20
30
41
60
219
32
47
63
85
270
70
105
140
138
342
115
172
230
205
393
10
13
19
91
12
17
23
105
12
18
24
26
116
24
36
48
43
145
42
64
85
57
186
12
16
35
159
12
18
24
49
196
27
41
54
78
248
45
67
89
116
286
13
17
28
155
19
29
38
45
196
31
47
63
66
225
14
19
30
155
15
23
31
43
178
7
SUPPLEMENTAL DESIGN ASSISTANCE
Span
Rating
24/16
27
27
28
SUPPLEMENTAL DESIGN ASSISTANCE
Table 7.1
Span
Rating
Limit
State
12
16
16 oc
L/360
L/240
L/180
M
Vs
L/360
L/240
L/180
M
Vs
L/360
L/240
L/180
M
Vs
L/360
L/240
L/180
M
Vs
L/360
L/240
L/180
M
Vs
585
877
1169
376
465
818
1228
1637
435
548
1169
1754
2338
579
702
2533
3800
5067
786
825
4482
6723
8964
1443
1237
226
339
453
213
338
317
475
634
246
397
453
679
905
327
509
981
1471
1961
443
598
1735
2603
3470
813
896
20 oc
24 oc
32 oc
48 oc
(a)
(b)
(c)
(Continued) Baseline Uniform Load Capacities(a,b,c) (psf)
Primary Axis Across Supports
Span (in., center-to-center)
19.2
24
32
SINGLE FLOOR
126
62
25
188
93
37
251
123
50
148
96
55
277
219
162
176
86
35
264
130
52
352
173
70
171
111
63
326
257
190
251
123
50
377
185
75
502
247
100
228
147
84
417
329
243
544
267
108
816
401
162
1088
535
216
308
198
113
491
387
286
963
473
191
1444
709
287
1925
946
383
565
363
205
735
579
427
40
48
16
24
32
29
124
22
33
45
34
145
32
48
64
44
186
69
103
138
59
218
122
183
244
106
326
10
15
20
21
107
14
21
28
24
126
20
30
40
31
161
44
65
87
42
189
77
116
154
75
282
Secondary Axis Across Supports
Span (in., center-to-center)
12
16
19.2
24
43
64
86
93
301
51
76
101
129
352
101
152
203
196
404
292
438
585
345
579
624
935
1247
615
928
17
25
33
53
219
20
29
39
73
256
39
59
78
111
293
113
170
226
195
420
241
362
483
347
673
12
18
23
31
172
14
21
28
42
202
28
42
55
63
231
80
120
160
109
331
171
256
341
194
530
10
14
28
159
14
20
27
41
182
39
59
79
71
261
84
126
168
125
417
Values represent unfactored total load (= D + L) and are applicable when λ = 0.8 and dead load (D) = 10 psf.
Applicable when nominal 2-in. framing members are used for supports less than 48 in. o.c., and nominal 4-in. framing members are used for supports at 48 in. o.c.
Tabulated values are based on the following loading configurations:
Primary Axis Across Supports
Support Spacing (s)
No. of Spans
3
s ≤ 32 in. o.c.
2
s > 32 in. o.c.
Secondary Axis Across Supports
Support Spacing (s)
No. of Spans
3
s ≤ 16 in. o.c.
2
24 in. ≥ s > 16 in.
APA/EWS
LRFD STRUCTURAL-USE
PANELS SUPPLEMENT
GUIDELINE
TO LRFD FOR STRUCTURAL
COMPOSITE LUMBER
Table 7.2
OSB Uniform Load Capacities(a,b,c) (psf)
Limit
State
12
16
24/0
L/360
L/240
L/180
M
Vs
L/360
L/240
L/180
M
Vs
L/360
L/240
L/180
M
Vs
L/360
L/240
L/180
M
Vs
L/360
L/240
L/180
M
Vs
234
351
468
273
342
304
456
608
348
393
448
672
896
402
435
877
1315
1754
678
548
1559
2338
3118
915
702
91
136
181
154
248
118
177
235
197
286
174
260
347
227
315
339
509
679
382
397
604
905
1207
516
509
32/16
40/20
48/24
Primary Axis Across Supports
Span (in., center-to-center)
19.2
24
32
SHEATHING
50
25
10
75
37
15
100
49
20
108
70
40
204
161
119
65
32
13
98
48
19
131
64
26
138
89
51
234
185
137
96
47
19
144
71
29
193
95
38
159
102
59
259
204
151
188
93
37
283
139
56
377
185
75
266
171
97
326
257
190
335
164
67
502
247
100
670
329
133
359
231
131
417
329
243
APA/EWS
40
48
Secondary Axis Across Supports
Span (in., center-to-center)
12
16
19.2
24
12
15
22
100
15
23
30
36
126
27
40
54
48
161
43
65
87
90
219
63
94
126
106
219
98
147
196
152
270
217
326
435
246
342
356
535
713
367
393
10
13
22
91
12
17
27
105
12
18
24
31
116
24
36
48
51
145
42
64
85
68
186
17
25
34
52
159
24
36
49
61
159
38
57
76
86
196
84
126
168
139
248
138
207
276
208
286
12
18
24
30
126
17
26
34
35
126
27
40
54
49
155
59
89
119
78
196
98
146
195
116
225
13
17
23
99
13
20
26
32
122
29
44
58
51
155
48
72
96
75
178
7
SUPPLEMENTAL DESIGN ASSISTANCE
Span
Rating
24/16
29
29
30
SUPPLEMENTAL DESIGN ASSISTANCE
Table 7.2
(Continued) OSB Uniform Load Capacities(a,b,c) (psf)
Span
Rating
Limit
State
12
16
24/0
L/360
L/240
L/180
M
Vs
L/360
L/240
L/180
M
Vs
L/360
L/240
L/180
M
Vs
L/360
L/240
L/180
M
Vs
L/360
L/240
L/180
M
Vs
234
351
468
273
342
304
456
608
348
393
448
672
896
402
435
877
1315
1754
678
548
1559
2338
3118
915
702
91
136
181
154
248
118
177
235
197
286
174
260
347
227
315
339
509
679
382
397
604
905
1207
516
509
24/16
32/16
40/20
48/24
Primary Axis Across Supports
Span (in., center-to-center)
19.2
24
32
40
STRUCTURAL I SHEATHING
50
25
10
75
37
15
10
100
49
20
13
108
70
40
22
204
161
119
91
65
32
13
98
48
19
12
131
64
26
17
138
89
51
27
234
185
137
105
96
47
19
12
144
71
29
18
193
95
38
24
159
102
59
31
259
204
151
116
188
93
37
24
283
139
56
36
377
185
75
48
266
171
97
51
326
257
190
145
335
164
67
42
502
247
100
64
670
329
133
85
359
231
131
68
417
329
243
186
APA/EWS
48
12
15
22
100
15
23
30
36
126
27
40
54
48
161
Secondary Axis Across Supports
Span (in., center-to-center)
12
16
19.2
24
73
109
146
139
219
105
158
211
164
219
164
246
328
234
270
365
547
730
381
342
598
897
1196
570
393
28
42
56
79
159
41
61
82
93
159
64
95
127
133
196
141
212
282
215
248
231
347
463
321
286
20
30
40
45
126
29
43
58
53
126
45
67
90
75
155
100
150
200
121
196
164
245
327
180
225
10
15
20
30
99
14
21
28
35
99
22
33
44
49
122
49
74
98
78
155
80
121
161
116
178
LRFD STRUCTURAL-USE
PANELS SUPPLEMENT
GUIDELINE
TO LRFD FOR STRUCTURAL
COMPOSITE LUMBER
Table 7.2
12
16
16 oc
L/360
L/240
L/180
M
Vs
L/360
L/240
L/180
M
Vs
L/360
L/240
L/180
M
Vs
L/360
L/240
L/180
M
Vs
L/360
L/240
L/180
M
Vs
585
877
1169
451
465
818
1228
1637
521
548
1169
1754
2338
694
702
2533
3800
5067
942
825
4482
6723
8964
1731
1237
226
339
453
255
338
317
475
634
294
397
453
679
905
391
509
981
1471
1961
531
598
1735
2603
3470
975
896
32 oc
48 oc
(b)
(c)
Primary Axis Across Supports
Span (in., center-to-center)
19.2
24
32
SINGLE FLOOR
126
62
25
188
93
37
251
123
50
178
115
66
277
219
162
176
86
35
264
130
52
352
173
70
205
132
75
326
257
190
251
123
50
377
185
75
502
247
100
273
175
100
417
329
243
544
267
108
816
401
162
1088
535
216
370
237
135
491
387
286
963
473
191
1444
709
287
1925
946
383
678
435
246
735
579
427
40
48
16
24
32
35
124
22
33
45
40
145
32
48
64
52
186
69
103
138
70
218
122
183
244
127
326
10
15
20
25
107
14
21
28
28
126
20
30
40
37
161
44
65
87
49
189
77
116
154
89
282
Secondary Axis Across Supports
Span (in., center-to-center)
12
16
19.2
24
133
199
266
165
301
157
236
314
229
352
314
471
628
351
404
906
1359
1812
618
579
1933
2900
3866
1104
928
51
77
103
94
219
61
91
122
130
256
122
182
243
198
293
351
526
702
349
420
748
1123
1497
622
673
36
55
73
53
172
43
64
86
73
202
86
129
172
111
231
248
372
496
195
331
529
793
1058
347
530
18
27
36
35
136
21
32
42
48
159
42
63
84
72
182
122
183
244
126
261
260
390
520
223
417
Values represent unfactored total load (= D + L) and are applicable when λ = 0.8 and dead load (D) = 10 psf.
Applicable when nominal 2-in. framing members are used for supports less than 48 in. o.c., and nominal 4-in. framing members are used for supports at 48 in. o.c.
Tabulated values are based on the following loading configurations:
Primary Axis Across Supports
Support Spacing (s)
No. of Spans
3
s ≤ 32 in. o.c.
2
s > 32 in. o.c.
Secondary Axis Across Supports
Support Spacing (s)
No. of Spans
3
s ≤ 16 in. o.c.
2
24 in. ≥ s > 16 in.
APA/EWS
7
SUPPLEMENTAL DESIGN ASSISTANCE
Limit
State
24 oc
(a)
(Continued) OSB Uniform Load Capacities(a,b,c) (psf)
Span
Rating
20 oc
31
31
32
SUPPLEMENTAL DESIGN ASSISTANCE
Table 7.3
5-Ply Plywood Uniform Load Capacities(a,b,c) (psf)
Span
Rating
Limit
State
12
16
32/16
L/360
L/240
L/180
M
Vs
L/360
L/240
L/180
M
Vs
L/360
L/240
L/180
M
Vs
493
740
986
402
478
965
1447
1929
678
602
1715
2572
3430
915
772
191
286
382
227
347
373
560
747
382
437
664
996
1328
516
560
L/360
L/240
L/180
M
Vs
L/360
L/240
L/180
M
Vs
L/360
L/240
L/180
M
Vs
493
740
986
402
694
965
1447
1929
678
875
1715
2572
3430
915
1122
191
286
382
227
503
373
560
747
382
634
664
996
1328
516
813
40/20
48/24
32/16
40/20
48/24
Primary Axis Across Supports
Span (in., center-to-center)
19.2
24
32
40
SHEATHING
106
52
21
13
159
78
32
20
212
104
42
27
159
102
59
31
284
224
166
127
207
102
41
26
311
153
62
39
414
204
82
52
266
171
97
51
358
282
209
160
368
181
73
47
553
271
110
70
737
362
147
93
359
231
131
68
459
362
267
204
STRUCTURAL I SHEATHING
106
52
21
13
159
78
32
20
212
104
42
27
159
102
59
31
413
325
240
183
207
102
41
26
311
153
62
39
414
204
82
52
266
171
97
51
520
410
303
231
368
181
73
47
553
271
110
70
737
362
147
93
359
231
131
68
666
525
388
295
APA/EWS
48
Secondary Axis Across Supports
Span (in., center-to-center)
12
16
19.2
24
13
17
22
110
17
25
33
36
138
30
44
59
48
177
98
147
196
152
270
217
326
435
246
342
356
535
713
367
393
38
57
76
86
196
84
126
168
139
248
138
207
276
208
286
27
40
54
49
155
59
89
119
78
196
98
146
195
116
225
13
20
26
32
122
29
44
58
51
155
48
72
96
75
178
13
17
22
159
17
25
33
36
200
30
44
59
48
256
164
246
328
234
377
365
547
730
381
478
598
897
1196
570
550
64
95
127
133
274
141
212
282
215
347
231
347
463
321
399
45
67
90
75
216
100
150
200
121
273
164
245
327
180
314
22
33
44
49
170
49
74
98
78
215
80
121
161
116
248
LRFD STRUCTURAL-USE
PANELS SUPPLEMENT
GUIDELINE
TO LRFD FOR STRUCTURAL
COMPOSITE LUMBER
Table 7.3
12
16
20 oc
L/360
L/240
L/180
M
Vs
L/360
L/240
L/180
M
Vs
L/360
L/240
L/180
M
Vs
L/360
L/240
L/180
M
Vs
900
1350
1801
521
602
1286
1929
2572
694
772
2787
4180
5573
942
908
4930
7395
9860
1731
1360
349
523
697
294
437
498
747
996
391
560
1079
1618
2158
531
658
1909
2863
3817
975
986
48 oc
(b)
(c)
Primary Axis Across Supports
Span (in., center-to-center)
19.2
24
32
SINGLE FLOOR
193
95
38
290
142
58
387
190
77
205
132
75
358
282
209
276
136
55
414
204
82
553
271
110
273
175
100
459
362
267
599
294
119
898
441
179
1197
588
238
370
237
135
539
425
314
1059
520
211
1588
780
316
2118
1040
421
678
435
246
808
636
470
40
48
24
37
49
40
160
35
52
70
52
204
76
114
152
70
239
134
201
268
127
358
16
23
31
28
138
22
33
44
37
177
48
72
96
49
208
85
127
170
89
310
Secondary Axis Across Supports
Span (in., center-to-center)
12
16
19.2
24
157
236
314
229
352
314
471
628
351
404
906
1359
1812
618
579
1933
2900
3866
1104
928
61
91
122
130
256
122
182
243
198
293
351
526
702
349
420
748
1123
1497
622
673
43
64
86
73
202
86
129
172
111
231
248
372
496
195
331
529
793
1058
347
530
21
32
42
48
159
42
63
84
72
182
122
183
244
126
261
260
390
520
223
417
Values represent unfactored total load (= D + L) and are applicable when λ = 0.8 and dead load (D) = 10 psf.
Applicable when nominal 2-in. framing members are used for supports less than 48 in. o.c., and nominal 4-in. framing members are used for supports at 48 in. o.c.
Tabulated values are based on the following loading configurations:
Primary Axis Across Supports
Support Spacing (s)
No. of Spans
3
s ≤ 32 in. o.c.
2
s > 32 in. o.c.
Secondary Axis Across Supports
Support Spacing (s)
No. of Spans
3
s ≤ 16 in. o.c.
2
24 in. ≥ s > 16 in.
APA/EWS
7
SUPPLEMENTAL DESIGN ASSISTANCE
Limit
State
32 oc
(a)
(Continued) 5-Ply Plywood Uniform Load Capacities(a,b,c) (psf)
Span
Rating
24 oc
33
33
34
SUPPLEMENTAL DESIGN ASSISTANCE
Table 7.4
Span
Rating
Limit
State
12
16
32/16
L/360
L/240
L/180
M
Vs
L/360
L/240
L/180
M
Vs
L/360
L/240
L/180
M
Vs
493
740
986
369
435
965
1447
1929
621
548
1715
2572
3430
839
702
191
286
382
209
315
373
560
747
351
397
664
996
1328
473
509
L/360
L/240
L/180
M
Vs
493
740
986
369
607
191
286
382
209
440
L/360
L/240
L/180
M
Vs
L/360
L/240
L/180
M
Vs
900
1350
1801
478
548
1286
1929
2572
636
702
349
523
697
270
397
498
747
996
359
509
40/20
48/24
32/16
20 oc
24 oc
(a)
(b)
(c)
4-Ply Plywood Uniform Load Capacities(a,b,c) (psf)
Primary Axis Across Supports
Span (in., center-to-center)
19.2
24
32
40
SHEATHING
106
52
21
13
159
78
32
20
212
104
42
27
146
94
54
29
259
204
151
116
207
102
41
26
311
153
62
39
414
204
82
52
244
157
90
47
326
257
190
145
368
181
73
47
553
271
110
70
737
362
147
93
329
212
120
63
417
329
243
186
STRUCTURAL I SHEATHING
106
52
21
13
159
78
32
20
212
104
42
27
146
94
54
29
361
285
211
161
SINGLE FLOOR
193
95
38
24
290
142
58
37
387
190
77
49
188
121
69
37
326
257
190
145
276
136
55
35
414
204
82
52
553
271
110
70
250
161
92
48
417
329
243
186
48
Secondary Axis Across Supports
Span (in., center-to-center)
12
16
19.2
24
13
17
21
100
17
25
33
33
126
30
44
59
44
161
69
104
139
102
1045
154
232
309
165
1326
253
379
506
246
1527
27
40
54
58
758
60
90
119
94
961
98
147
196
139
1106
19
29
38
34
596
42
63
84
53
756
69
104
138
78
871
14
19
22
470
21
31
41
35
596
34
51
68
51
685
13
17
21
139
104
156
208
143
2115
40
60
81
82
1532
29
43
57
46
1206
14
21
28
31
949
16
23
31
26
126
22
33
44
34
161
111
167
223
154
1366
223
334
446
235
1567
43
65
86
88
990
86
129
173
133
1135
30
46
61
50
779
61
91
122
75
893
15
22
30
33
614
30
45
60
49
703
Values represent unfactored total load (= D + L) and are applicable when λ = 0.8 and dead load (D) = 10 psf.
Applicable when nominal 2-in. framing members are used for supports less than 48 in. o.c., and nominal 4-in. framing members are used for supports at 48 in. o.c.
Tabulated values are based on the following loading configurations:
Primary Axis Across Supports
Support Spacing (s)
No. of Spans
3
s ≤ 32 in. o.c.
2
s > 32 in. o.c.
Secondary Axis Across Supports
Support Spacing (s)
No. of Spans
3
s ≤ 16 in. o.c.
2
24 in. ≥ s > 16 in.
APA/EWS
LRFD STRUCTURAL-USE
PANELS SUPPLEMENT
GUIDELINE
TO LRFD FOR STRUCTURAL
COMPOSITE LUMBER
Table 7.5
Limit
State
12
16
24/0
L/360
L/240
L/180
M
Vs
L/360
L/240
L/180
M
Vs
L/360
L/240
L/180
M
Vs
257
386
514
228
342
493
740
986
336
435
965
1447
1929
565
548
100
149
199
129
248
191
286
382
190
315
373
560
747
319
397
40/20
(a)
(b)
(c)
3-Ply Plywood Uniform Load Capacities(a,b,c) (psf)
Span
Rating
32/16
35
35
Primary Axis Across Supports
Span (in., center-to-center)
19.2
24
32
40
SHEATHING
55
27
11
83
41
16
10
111
54
22
14
90
59
34
19
204
161
119
91
106
52
21
13
159
78
32
20
212
104
42
27
133
86
49
26
259
204
151
116
207
102
41
26
311
153
62
39
414
204
82
52
222
143
82
43
326
257
190
145
48
Secondary Axis Across Supports
Span (in., center-to-center)
12
16
19.2
24
13
17
19
100
17
25
33
31
126
14
21
28
51
607
32
47
63
85
751
70
105
140
138
953
12
18
24
49
545
27
41
54
78
691
13
17
28
429
19
29
38
45
544
14
19
30
428
Values represent unfactored total load (= D + L) and are applicable when λ = 0.8 and dead load (D) = 10 psf.
Applicable when nominal 2-in. framing members are used for supports less than 48 in. o.c., and nominal 4-in. framing members are used for supports at 48 in. o.c.
Tabulated values are based on the following loading configurations:
Secondary Axis Across Supports
Support Spacing (s)
No. of Spans
3
s ≤ 16 in. o.c.
2
24 in. ≥ s > 16 in.
APA/EWS
SUPPLEMENTAL DESIGN ASSISTANCE
Primary Axis Across Supports
Support Spacing (s)
No. of Spans
3
s ≤ 32 in. o.c.
2
s > 32 in. o.c.
7
36
SUPPLEMENTAL DESIGN ASSISTANCE
Table 7.6
Span
Rating
Limit
State
12
16
32/16
L/360
L/240
L/180
M
Vs
L/360
L/240
L/180
M
Vs
L/360
L/240
L/180
M
Vs
493
740
986
402
435
965
1447
1929
678
548
1715
2572
3430
915
702
191
286
382
227
315
373
560
747
382
397
664
996
1328
516
509
L/360
L/240
L/180
M
Vs
L/360
L/240
L/180
M
Vs
L/360
L/240
L/180
M
Vs
L/360
L/240
L/180
M
Vs
900
1350
1801
521
548
1286
1929
2572
694
702
2787
4180
5573
942
825
4930
7395
9860
1731
1237
349
523
697
294
397
498
747
996
391
509
1079
1618
2158
531
598
1909
2863
3817
975
896
40/20
48/24
20 oc
24 oc
32 oc
48 oc
(a)
(b)
(c)
COM-PLY Uniform Load Capacities(a,b,c) (psf)
Primary Axis Across Supports
Span (in., center-to-center)
19.2
24
32
SHEATHING
106
52
21
159
78
32
212
104
42
159
102
59
259
204
151
207
102
41
311
153
62
414
204
82
266
171
97
326
257
190
368
181
73
553
271
110
737
362
147
359
231
131
417
329
243
SINGLE FLOOR
193
95
38
290
142
58
387
190
77
205
132
75
326
257
190
276
136
55
414
204
82
553
271
110
273
175
100
417
329
243
599
294
119
898
441
179
1197
588
238
370
237
135
491
387
286
1059
520
211
1588
780
316
2118
1040
421
678
435
246
735
579
427
40
48
Secondary Axis Across Supports
Span (in., center-to-center)
12
16
19.2
24
13
20
27
31
116
26
39
52
51
145
47
70
93
68
186
13
17
22
100
17
25
33
36
126
30
44
59
48
161
69
104
139
102
270
154
232
309
165
342
253
379
506
246
393
27
40
54
58
196
60
90
119
94
248
98
147
196
139
286
19
29
38
34
155
42
63
84
53
196
69
104
138
78
225
14
19
22
122
21
31
41
35
155
34
51
68
51
178
24
37
49
40
145
35
52
70
52
186
76
114
152
70
218
134
201
268
127
326
16
23
31
28
126
22
33
44
37
161
48
72
96
49
189
85
127
170
89
282
111
167
223
154
352
223
334
446
235
404
643
965
1286
413
579
1372
2058
2744
737
928
43
65
86
88
256
86
129
173
133
293
249
373
498
233
420
531
797
1062
416
673
30
46
61
50
202
61
91
122
75
231
176
264
352
131
331
375
563
751
232
530
15
22
30
33
159
30
45
60
49
182
86
130
173
85
261
184
277
369
149
417
Values represent unfactored total load (= D + L) and are applicable when λ = 0.8 and dead load (D) = 10 psf.
Applicable when nominal 2-in. framing members are used for supports less than 48 in. o.c., and nominal 4-in. framing members are used for supports at 48 in. o.c.
Tabulated values are based on the following loading configurations:
Primary Axis Across Supports
Support Spacing (s)
No. of Spans
3
s ≤ 32 in. o.c.
2
s > 32 in. o.c.
Secondary Axis Across Supports
Support Spacing (s)
No. of Spans
3
s ≤ 16 in. o.c.
2
24 in. ≥ s > 16 in.
APA/EWS
LRFD STRUCTURAL-USE
PANELS SUPPLEMENT
GUIDELINE
TO LRFD FOR STRUCTURAL
COMPOSITE LUMBER
37
37
7.3 Design Example
Solving for WL in our example:
The following example provides an overview of the
general procedure for structural-use panel design under
uniform loads. This example helps to clarify the modifications necessary to design for applications that are not
represented in the load-span tables.
WL = [767 (120/242) - 1.2 (10)] / 1.6 = 92.4 psf
WT = WD + WL = 102 psf
The calculated uniform load controlled by panel design moment capacity is 102 psf (see Table 7.2).
Example - Roof Application
Panel:
1/2-inch nominal OSB Sheathing with a 32/16
span rating.
Application: Roof - primary axis spanning across supports spaced 24 inches o.c.
Calculate uniform load capacity and check results
using load-span tables. Assume a 10 psf dead load and
that design end-use conditions are consistent with reference end-use conditions.
Load Capacity - Planar (Rolling)
Shear
From Table 5.2, the baseline factored planar shear
capacity for Sheathing 32/16 is 0.363 kip/ft. From Table
4.2, the grade-construction factor for OSB planar shear
capacity is 1.0. The end-use adjustment factor is also 1.0.
The design planar shear capacity for this application is:
Load Capacity - Moment
7
λφvVsN = 0.363 (1.0) (1.0)
= 0.363 kip/ft
The design equation is:
λφvVsN = 1.2 (WD L /K) + 1.6 (WL L /K)
Where
λφbMN = (0.639) (1.2) (1.0)
L = 22.5 inches (clear span)
= 0.767 kip-in./ft
WD = Dead load = 10 psf
The design equation is:
WL = Live load
K = 20 for three or more spans, 19.2 for two spans,
λφbMN = 1.2 (WD L /K) + 1.6 (WL L /K)
2
2
and 24 for single span applications
This design equation simplifies to:
Where
L = 24 inches (span between centerline of
WL = [λφvVsN (K/L) - 1.2 WD] / 1.6
supports)
WD = Dead load = 10 psf
Solving for WL in our example:
WL = Live load
K = 120 for three or more spans, 96 for single and
WL = [363 (20/22.5) - 1.2 (10)] / 1.6 = 194 psf
two-span applications
This design equation simplifies to:
WL = [λφbMN (K/L2) - 1.2 WD] / 1.6
WT = WD + WL = 204 psf
The calculated uniform load controlled by panel design planar shear capacity is 204 psf (see Table 7.2).
APA/EWS
SUPPLEMENTAL DESIGN ASSISTANCE
From Table 5.1, the baseline factored moment capacity for Sheathing 32/16 is 0.639 kip-in./ft. From Table
4.2, the grade-construction factor for OSB moment capacity is 1.2 when the primary axis is across supports.
The end-use adjustment factor is 1.0. Design moment
capacity for this application is:
38
SUPPLEMENTAL DESIGN ASSISTANCE
Load Capacity - Deflection
From Table 5.1, the baseline stiffness for Sheathing
32/16 is 115 kip-in.2/ft. From Table 4.2, the grade-construction factor for OSB sheathing stiffness is 1.0. The
end-use adjustment factor is also 1.0. The design stiffness is:
For the example application, K1 = 1743, K2 (live load)
= 240, K2 (total load) = 180, and L = 24 - 1.5 + 0.25 =
22.75 inches.
For uniform roof live load:
WL = [115000/(22.753)] (1743/240) = 71 psf
(EI)N = (115) (1.0) (1.0)
Total uniform load for roof applications:
2
= 115 kip-in. /ft
WT = [115000/(22.753)] (1743/180) = 95 psf
The design equation is:
The total uniform load limited by the L/180 deflection criterion is 95 psf. The uniform roof live load limited
by the L/240 deflection criterion is 71 psf (see Table 7.2).
δ = W L4 / [K1 (EΙ)N]
Where
Example Summary
δ = Deflection criterion
L = Clear span plus support-width factor that is
Panel:
1/2-inch nominal OSB Sheathing with a
32/16 span rating.
Application: Roof - primary axis spanning across supports spaced 24 inches o.c.
equal to 0.25 inch for two-inch-nominal lumber
framing and 0.625 inch for four-inch-nominal
lumber framing.
K1 = 1743 for three spans, 2220 for two spans, and
Limit State
Moment
Planar Shear
Stiffness, L/240
Stiffness, L/180
921.6 for single span applications
The deflection criterion term may be expressed as:
δ = L/K2
Where K2 is a constant (180, 240, or 360).
Substituting the deflection criterion term into the design equation and rearranging yields:
Uniform Load Capacity
102 psf
204 psf
71 psf (live)
95 psf (total)
These values check with capacities provided in the
table of OSB uniform load capacities (Table 7.2) for the
corresponding application. The uniform load capacity for
this design is 71 psf, as governed by the live load deflection.
W = [(EΙ)N/L3] (K1/K2)
APA/EWS
LRFD STRUCTURAL-USE PANELS SUPPLEMENT
39
SECTION
PROPERTIES
8.1
General
40
8.2
Section and Weight Properties
40
Table 8.1 Panel Section and Weight Properties................... 40
Table 8.2 Relationship Between Span Rating and
Nominal Thickness ................................................ 40
APA/EWS
8
40
SECTION PROPERTIES
8.1 General
Section and weight properties are provided in Section 8.2. Nominal panel thicknesses tabulated in Table
8.1 were used to calculate section properties. The tabulated section properties were calculated assuming
homogeneous rectangular cross sections of one-foot width.
Relationships between nominal thickness and span
rating are provided in Table 8.2. The predominant nominal thickness available for each span rating is designated
by the letter “P”. The predominant nominal thickness is
also the appropriate thickness for establishing section properties for design.
Reference strength and stiffness may be calculated
using applicable section properties from Table 8.1 and
design capacities given in Table 5.1, Table 5.2, or Table
5.3. An example derivation is provided in Section 3.2.
8.2 Section and Weight Properties
Table 8.1
Panel Section and Weight Properties
Nominal
Thickness
(in.)
3/8
7/16
15/32
1/2
19/32
5/8
23/32
3/4
7/8
1
1-1/8
(a)
(b)
Approximate
Weight(b)
(psf)
1.1
1.3
1.4
1.5
1.8
1.9
2.2
2.3
2.6
3.0
3.3
Thickness
t
(in.)
0.375
0.437
0.469
0.500
0.594
0.625
0.719
0.750
0.875
1.000
1.125
Moment of
Inertia
I
(in.4/ft)
0.053
0.084
0.103
0.125
0.209
0.244
0.371
0.422
0.670
1.000
1.424
Area
A
(in.2/ft)
4.500
5.250
5.625
6.000
7.125
7.500
8.625
9.000
10.500
12.000
13.500
(a)
Section
Modulus
S
(in.3 /ft)
0.281
0.383
0.440
0.500
0.705
0.781
1.033
1.125
1.531
2.000
2.531
Statical
Moment
Q
(in.3/ft)
0.211
0.287
0.330
0.375
0.529
0.586
0.775
0.844
1.148
1.500
1.898
Shear
Constant
Ib/Q
(in.2/ft)
3.00
3.50
3.75
4.00
4.75
5.00
5.75
6.00
7.00
8.00
9.00
Properties based on rectangular cross section of 1-foot width.
Approximate plywood weight for calculating actual dead loads. For OSB and COM-PLY panels, increase tabulated weights by 10%.
Table 8.2
Relationship Between Span Rating and Nominal Thickness
Span Rating
3/8
7/16
15/32
1/2
Nominal Thickness (in.)
19/32
5/8
23/32
3/4
7/8
A
P
A
A
A
P
A
1
1-1/8
SHEATHING
24/0
24/16
32/16
40/20
48/24
16 oc
20 oc
24 oc
32 oc
48 oc
P
A
P
A
A
P
A
A
A
A
P
A
A
SINGLE FLOOR
A
P
A
P
P
A
P
P = Predominant nominal thickness for each span rating.
A = Alternative nominal thickness that may be available for each span rating. Check with suppliers regarding availability.
APA/EWS
ADDITIONAL
INFORMATION
About APA – The Engineered
Wood Association and Engineered
Wood Systems
APA – The Engineered Wood Association is
a nonprofit trade association whose member
mills produce approximately 75 percent of
the structural wood panel products manufactured in North America.
The Association’s trademark appears only
on products manufactured by member mills
and is the manufacturer’s assurance that
the product conforms to the standard shown on
the trademark. That standard may be an APA
performance standard, the Voluntary Product
Standard PS 1-95 for Construction and Industrial Plywood or Voluntary
Product Standard PS 2-92, Performance
Standards for Wood-Based Structural-Use
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APA’s services go far beyond quality testing
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Always insist on panels bearing the mark
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investment in the many trade services that
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The APA EWS trademark appears only on
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and testing and that products are manufactured in conformance with an APA or national standard such as ANSI Standard
A190.1, American National Standard for
Structural Glued Laminated Timber.
For additional information on wood
construction systems, contact APA – The
Engineered Wood Association, P.O. Box
11700, Tacoma, Washington 98411-0700,
or the nearest APA regional field office
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EWS Publications Index, Form S400
The product use recommendations in this publication are based on the continuing programs of
laboratory testing, product research, and field
experience of APA – The Engineered Wood
Association and Engineered Wood Systems.
However, because APA and Engineered Wood
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workmanship or the conditions under which
structural panels and engineered wood products
are used, those organizations cannot accept
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12-96
5M