DESIGNING FOR NEW ASCE 7-16 WIND LOADS PER THE
2018 WFCM (STD355)
John “Buddy” Showalter, P.E.
Vice President, Technology Transfer
American Wood Council
Description
The Wood Frame Construction Manual (WFCM) for One- and Two-Family Dwellings (ANSI/AWC
WFCM-2018) is referenced in the 2018 International Building Code (IBC) and 2018 International
Residential Code (IRC). The 2018 WFCM uses gravity and lateral loads based on ASCE 7-16 Minimum
Design Loads and Associated Criteria for Buildings and Other Structures which includes increased
components and cladding roof wind loads. Design of Wood Frame Buildings for High Wind, Snow,
and Seismic Loads (2018 WFCM Workbook) includes a design example, helpful checklist, and
background information for design of a wood-frame structure in accordance with the 2018 WFCM.
Using plans from a 2-story residence, a structure is prescriptively designed to resist high wind,
seismic, and typical residential gravity loads. This webinar will deal specifically with design of roof
systems, and appropriate connections between roof, floor, wall, and foundations to maintain load
path for wind uplift. New shear wall aspect ratio limits for wind will also be examined. Participants
are strongly encouraged to view the free recorded webinar Significant Changes to the
2018 WFCM (STD350) prior to this webinar.
Learning Objectives
1.
2.
3.
4.
Describe changes to the 2018 WFCM and their impact
Evaluate new roof wind provisions based on ASCE 7-16
Recognize the addition of deformed-shank fasteners and other criteria to address new wind load provisions
Design with new 2018 WFCM shear wall aspect ratio limits for wind
1
This presentation is protected by US and International
Copyright laws. Reproduction, distribution, display and use
of the presentation without written permission of AWC is
prohibited.
© American Wood Council 2018
American Wood Council
# 50111237
Designing for New ASCE 7-16 Wind
Loads per the 2018 WFCM (STD355)
Course #: STD355L & STD355OD
John “Buddy” Showalter, P.E.
December 6, 2018
• Credit(s) earned on
completion of this course will
be reported to AIA CES for
AIA members. Certificates of
Completion for both AIA
members and non-AIA
members are available upon
request.
• This course is registered with AIA
CES for continuing professional
education. As such, it does not
include content that may be
deemed or construed to be an
approval or endorsement by the
AIA of any material of
construction or any method or
manner of handling, using,
distributing, or dealing in any
material or product.
• Questions related to specific
materials, methods, and services will
be addressed at the conclusion of this
presentation.
2
Polling Question
ϭ͘What is your profession?
a) Architect
b) Engineer
c) Code Official
d) Fire^ĞƌǀŝĐĞ
e) Builder/Manufacturer/Other
3
Course Outline
•
•
•
•
Code Acceptance of Standards Discussed
Background on Design Loads – ASCE/SEI 7-16 C&C Wind Loads
Design Example Parameters
Prescriptive Provisions – Wood Frame Solutions
Reference Material
4
Reference Codes and Standards
• 2012 WFCM
• 2015 WFCM
• 2018 WFCM
→ 2012 IRC/IBC
→ 2015 IRC/IBC
→ 2018 IRC/IBC
• 2018 WFCM References
o
o
o
ASCE/SEI 7-16
2018 NDS
2015 SDPWS
5
Polling Question
Ϯ͘Have you ever used the WFCM to design all or part of
a residential structure?
a) Yes
b) No
6
Polling Question
ϯ͘Have you used the WFCM to design non-res buildings
per IBC 2309?
a) Yes
b) No
7
ASCE/SEI 7-16 Wind Load Changes
C&C Loads
• Increase in hurricane regions
• Larger area edge roof zones
• Interior roof zone pressures increase most
8
ASCE/SEI 7-16 Wind Load Changes (cont’d)
C&C Roof Coefficients (suction)
C&C Roof Overhang Coefficients (suction)
9
2018
E D I T I O N
WFCM
®
®
WOOD
MANUAL
WOOD FRAME
FRAMECONSTRUCTION
CONSTRUCTION
MANUAL
for One- and Two-Family Dwellings
WORKBOOK
DESIGN OF WOOD FRAME BUILDINGS FOR
HIGH WIND, SNOW, AND SEISMIC LOADS
APPROVED
AUGUST 7, 2017
AMERICAN
WOOD
COUNCIL
10
WFCM WB
FOREWORD
This Wood Frame Construction Manual
Workbook (WFCM Workbook) provides a design
example and typical checklist related to design of a
wood-frame structure in accordance with the
American Wood Council’s (AWC) Wood Frame
Construction Manual (WFCM) for One- and TwoFamily Dwellings, 2018 Edition. The design
example uses plans from a 2-story residence
designed to resist high wind, seismic, and snow
loads. All three loading conditions are evaluated in
this example to show the broad range of the WFCM
applicability. The authority having jurisdiction
should be consulted for applicable load conditions.
The design example is based primarily on
prescriptive provisions found in Chapter 3 of the
WFCM. References to tables and section numbers
are for those found in the 2018 WFCM, unless noted
otherwise. Additional engineering provisions or
alternate solutions are provided where necessary.
All loads and resistances are based on allowable
stress design. See the AWC website (www.awc.org)
for an in-depth overview of the WFCM.
While building codes (and the WFCM) are
organized based on the construction sequence
(foundation to roof), this design example is
organized based on the typical design sequence
(roof to foundation).
Special effort has been made to assure that the
information presented in this document reflects the
state of the art. However, the American Wood
Council does not assume responsibility for
particular designs or calculations prepared from this
publication.
AWC invites and welcomes comments,
inquiries, and suggestions relative to the provisions
of this document.
American Wood Council
The design example is based in part on AWC’s Colonial Homes Idea House in Williamsburg, VA designed by nationally
acclaimed architect William E. Poole. The house was opened to the public in June 1995 and was featured in the October
1995 issue of Colonial Homes magazine.
The colonial style home featured both traditional and modern wood applications. The façade replicates an historic home in
Connecticut. Clad in southern pine siding, the house had glulam door headers, oak floors, and antiqued wood kitchen
cabinets. But what caught visitors’ attention most were the intricate wood moldings throughout the house and the inlaid
wood design bordering the foyer floor.
11
WFCM WB
EFFECTIVE USE OF THE WFCM WORKBOOK
The following key explains the color code and nomenclature used throughout the WFCM Workbook.
Value
Indicates “value” may be used for design – could include multiple options.
Value
Bold font indicates “value” controls design.
OK
Indicates “value” meets design criteria.
NG
Indicates “value” does not meet design criteria.
Indicates significant change to 2018 WFCM Workbook vs. 2015 WFCM Workbook.
For ease of reference, Tables created in the WFCM Workbook are numbered to correspond with the respective section in
which they are located. All table numbers are preceded by a capital “W” (e.g. Table W4.4) to distinguish them from Tables
which are referenced in the WFCM (e.g. Table 3.15).
Abbreviations used in the WFCM Workbook
• 1F – one floor (for calculating loads)
• 2F – two floors (for calculating loads)
• C – ceiling (for calculating loads)
• DFL – Douglas Fir-Larch
• FHS – full height stud
• HF – Hem-Fir
• L – lateral load or header span
• NFH – number of full height studs
• NP – not permitted
• OH – overhang
• PSW – perforated shear wall
• R – roof (for calculating loads)
• S – shear load
• SP – Southern Pine
• SPF – Spruce-Pine-Fir
• SDPWS – Special Design provisions for Wind and Seismic
• SSW – segmented shear wall
• U – uplift load (not overturning)
• w – unit lateral load per linear foot
• WSP – wood structural panel
• Z – connection lateral design value
12
WFCM WB
Table of Contents
Part
Title
Page
I
General Information .............................................. 1
II
Roof Story Design ................................................ 13
III
Second Story Design ............................................ 33
IV
First Story Design ................................................. 53
13
WFCM WB
GENERAL
INFORMATION
Building Description ..............................................2
Loads on the Building ............................................4
WFCM Applicability Limitations ........................5
Prescriptive Design Limitations............................6
Load Paths ..............................................................7
Checklist..................................................................8
14
WFCM WB
BUILDING DESCRIPTION
Figure 1: Isometric view (roof overhangs not shown).
15
WFCM WB
BUILDING DESCRIPTION
North
Wall Heights
Finished Grade to Foundation Top
Floor Assembly Height
Roof Pitch
House Mean Roof Height
Roof Overhangs
Building Length (L)
Building Width (W)
Top plate to ridge height
= 9'
= 1'
= 1'
= 7:12
= 24.7'
= 2'
= 40'
= 32'
= 9.3'
Windows
Typical 3'x4'-6"
Foyer 6'x4'-6"
Kitchen 4'x4'-6"
Bath 4'x6'
Doors
Typical 3'x7'-6"
Foyer 6'x7'-6"
Kitchen 9'x7'-6"
16
WFCM WB
LOADS ON THE BUILDING
Structural systems in the WFCM 2018 Edition have been sized using dead, live, snow, seismic and wind loads in accordance
with ASCE/SEI 7-16 Minimum Design Loads and Associated Criteria for Buildings and Other Structures. Provisions of the
2018 International Residential Code (IRC) are referenced as needed.
Lateral Loads:
Wind:
3-second gust wind speed in Exposure Category B (700 yr. return)
= 160 mph
Seismic:
Simplified Procedure (ASCE 7-16 Section 12.14)
Seismic Design Category (SDC) – (ASCE 7-16 Section 11.6 and IRC Subcategory)
= D1
Vertical force distribution factor (F) – (ASCE 7-16 Section 12.14.8.1)
= 1.2
Gravity Loads*:
Roof:
Roof Dead Load
Ground Snow Load, Pg
Roof Live Load
=
=
=
10 psf
30 psf
20 psf
Ceiling:
Roof Ceiling Load
=
10 psf
*Assumptions vary for wind and seismic dead loads
Floors:
First Floor Live Load
Second Floor Live Load
Attic Floor Live Load
Floor Dead Load
=
=
=
=
40 psf
30 psf
30 psf
10 psf
Walls:
Wall Dead Load
=
11 psf
Deflection limits per 2018 IRC
Roof Rafters with flexible Ceiling Attached
Roof Rafters with no Ceiling Attached
Raised Ceiling Joists with flexible finish
Floor Joists
Exterior Studs (gypsum interior)
L/Δ =
L/Δ =
L/Δ =
L/Δ =
H/Δ =
240
180
240
360
180
Note: See comparable deflection limits in 2018 IBC
section 2308 for joists and rafters.
2018 International Residential Code for One- and Two-Family
Dwellings, International Code Council, Inc., Washington, DC.
Reproduced with permission. All rights reserved. www.iccsafe.org
d. Deflection for exterior walls with interior gypsum board finish shall
be limited to an allowable deflection of H/180.
17
WFCM WB
WFCM APPLICABILITY LIMITATIONS
The following table is used to determine whether the building geometry is within the applicability limitations of the WFCM.
Conditions not complying with the limitations shall be designed in accordance with accepted engineer practice (see WFCM
1.1.3).
Table W1.1 Applicability Limitations
Attribute
Limitation
Design Case

BUILDING DIMENSIONS
Mean Roof Height (MRH)
maximum
33'
24.7'

Number of Stories
maximum
3
3

Building Dimension (L or W)
maximum
80'
40'

18
WFCM WB
PRESCRIPTIVE DESIGN LIMITATIONS
The following table is used to determine whether the building geometry is within the applicability limitations of the WFCM
Chapter 3 prescriptive provisions. Conditions not complying with the limitations shall be designed in accordance with
WFCM Chapter 2 (see WFCM 3.1.3).
Table W1.2 Prescriptive Design Limitations
Element
Limitation
Design
Case

Joist Span
26'
16'

Joist Spacing
24"
16"




Attribute
FLOOR SYSTEMS (3.1.3.2)
Lumber
Joists
Cantilevers/Setback - Supporting loadbearing walls d
N/A
Cantilevers - Supporting non-loadbearing walls
L/4
N/A
Vertical Floor Offset
df
N/A
Table 3.16B Lmin=12.5' and
Lmax=74' (interpolated); Table
3.16C1 Lmax=80'
Lesser of 12' or 50% of
Diaphragm Dimension
L=40'
L=25.5'
(attic)

12'

Loadbearing Wall Height
10'
9'
Non-Loadbearing Wall Height
20'
18.3'
Wall Stud Spacing
24"
16"
Shear Wall Line Offset
4'
0
No offset unless per Exception
0
3½:1 (WSP) 2:1 (Gypsum)
3:1






Rafter Span (Horizontal Projection)
26'
16'
Rafter Spacing
24"
16"
Eave Overhang Length
Lesser of 2' or rafter length/3
2'
Rake Overhang Length*
Lesser of 2' or outlooker length/2 2'
Roof Slope
1.5 - 12:12
Floor
Floor Diaphragm Aspect Ratio
Diaphragms
Floor Diaphragm Openings
WALL SYSTEMS (3.1.3.3)
Wall Studs
Shear Walls Shear Wall Story Offset
Shear Wall Segment Aspect Ratio
ROOF SYSTEMS (3.1.3.4)
Lumber
Rafters
Table 3.16A1 Lmin=12.7' and
Lmax=70.6' (interpolated); Table
3.16C1 Lmax=80'
*Rake overhangs using lookout blocks shall not exceed 9". (WFCM 3.1.3.4c)
Roof
Roof Diaphragm Aspect Ratio
Diaphragms
7:12





L=40

19
2
WFCM
GENERAL INFORMATION
Table 1
Applicability Limitations
Attribute
Limitation
Reference
Section
Figures
1.1.3.1a
1.1.3.1a
1.1.3.1b
1.2
-
BUILDING DIMENSIONS
Mean Roof Height (MRH)
Number of Stories
Building Length and Width
33'
3
80'
LOAD ASSUMPTIONS
(See Chapter 2 or Chapter 3 tables for load assumptions
applicable to the specific tabulated requirement)
Load Type
Load Assumption
Partition Dead Load
0-8 psf of floor area
Wall Assembly Dead Load
11-18 psf
Floor Dead Load
10-20 psf
Roof/Ceiling Assembly Dead Load
0-25 psf
Floor Live Load
30-40 psf
Roof Live Load
20 psf
Ceiling Live Load
10-20 psf
Ground Snow Load
0-70 psf
Wind Load
Seismic Load
90-195 mph wind speed
(3-second gust)
Exposure B, C, and D (See Figure 1.1)
Seismic Design Category (SDC)
SDC A, B, C, D0, D1, and D2
Copyright © American Wood Council. Downloaded/printed pursuant to License Agreement. No reproduction or transfer authorized.
AMERICAN WOOD COUNCIL
20
WFCM WB
ROOF STORY DESIGN
Roof and Ceiling Framing ...................................14
Roof and Ceiling Sheathing.................................20
Wall Framing .......................................................22
Connections ..........................................................24
Framing and Connection Summary ...................31
21
WFCM WB
Figure W4.1 Roof and Ceiling Framing - Finished Attic Details
FINISHED ATTIC
Cross Section (East Section)
Roof Framing Plan (East Section)
Ceiling Framing Plan (East Section)
22
WFCM WB
Figure W4.2 Roof and Ceiling Framing – Raised Ceiling Details
Cross Section (West Section)
Roof Framing Plan (West Section)
Ceiling Framing Plan (West Section)
23
WFCM WB
Roof Framing – Finished Attic
Lumber Rafters (WFCM 3.5.1.1)
Assuming flexible finish ceiling attached to rafters, choose rafters from Tables 3.26B (dead and live
load), 3.26E (dead and snow load), and 3.26M (wind uplift) and evaluate roof live, wind, and snow
load spans. The smaller span controls.
Ground Snow Load: ....................................................................................
Live Load: ...................................................................................................
Dead Load: ..................................................................................................
Three second gust wind speed (700 yr) and exposure category: ................
Rafter Vertical Displacement L/Δ: ............................................................
Required Span (Horizontal Projection):......................................................
Rafter Span Adjustment - Thrust (Tables 3.26A-L Footnote 1): ................
Sloped Roof Adjustment (Tables 3.26A-C Footnote 2): ............................
Pitch and deflection limit adjustment (Table 3.26M Footnote 1): ..............
30 psf
20 psf
10 psf
160 mph Exp. B
240
16 ft.
1.0 (Ctf)
1.05 (Csr)
1.09 (Cpd)
Table W4.1 Selection of Species, Grade, Size, and Spacing for Rafters: (Table 3.26B, E & M)
Species
Douglas FirHem-Fir
Southern Pine
Spruce-Pine-Fir
Larch
Spacing
16"
16"
16"
16"
Grade
#2
#2
#2
#2
Table 3.26B Span (Lt) 2x8
18'-5"
2x8
17'-3"
2x8
17'-1"
2x8
17'-9"
Live Load Span
18.4(1.0)(1.05) 17.3(1.0)(1.05) 17.1(1.0)(1.05) 17.75(1.0)(1.05)=
LLL=Lt(Ctf)(Csr)
= 19'-4" Ok
= 18'-2" Ok
= 18'-0" Ok
18'-6" Ok
Table 3.26E Span (Lt) 2x10 18'-9"
2x10 18'-2" 2x10 16'-10" 2x10
18'-5"
Snow Load Span
18.75(1.0) =
18.2(1.0) =
16.8(1.0) =
18.4(1.0) =
LSL=Lt(Ctf)
18'-9" Ok
18'-2" Ok
16'-10" Ok
18'-5" Ok
Table 3.26M Span (Lt) 2x10 17'-3" 2x10 16'-2" 2x10 14'-10" 2x10
16'-8"
Wind Load Span
17.25(1.09) =
16.2(1.09) =
14.8(1.09) =
16.7(1.09) =
LWL=Lt(Cpd)
18'-7" Ok
17'-7" Ok
16'-2" Ok
18'-2" Ok
Notes: as an energy consideration, 2x12 rafters might be a minimum requirement for batt insulation.
Trial
and
error
Trial
and
error
Trial
and
error
Ridge Beams (WFCM 3.5.1.4)
Since thrust is accounted for in rafter selection, per 3.5.1.4 exception use:
1x12
Ridge Board
* Alternatively, a Ridge Beam could be designed per Table 3.29. Additional columns at beam ends would
be required to establish load path to the foundation. Also, fasteners will need to be designed to resist
uplift from the rafters at each end of the ridge beam.
Ground Snow Load: ......................................................................
30
psf
Live Load: ......................................................................................
20
psf
Dead Load: .....................................................................................
10
psf
Required Span: ...............................................................................
25' - 6"
Building Width: .............................................................................
32' - 0" (interpolation req’d)
5-1/8" x 19-1/4" or 3-1/8" x 24-3/4" 20F-1.5E Glulam with Fvx=210psi OK
24
320
WFCM
PRESCRIPTIVE DESIGN
Table 3.26M
(Cont.)
Exposure B
Rafter Deflection Limit = L/180
Maximum Rafter Spans for Common Lumber Species Resisting Uplift
Loads due to Wind (12:12 Slope)
Wind Speed 3-second gust (mph)
(See Figure 1.1)
Rafter
Spacing
(in.)
12
16
19.2
24
150
2x4
Species
Grade
DFL
DFL
DFL
DFL
HF
HF
HF
HF
SP
SP
SP
SP
SPF
SPF
SPF
SPF
DFL
DFL
DFL
DFL
HF
HF
HF
HF
SP
SP
SP
SP
SPF
SPF
SPF
SPF
DFL
DFL
DFL
DFL
HF
HF
HF
HF
SP
SP
SP
SP
SPF
SPF
SPF
SPF
DFL
DFL
DFL
DFL
HF
HF
HF
HF
SP
SP
SP
SP
SPF
SPF
SPF
SPF
SS
No.1
No.2
No.3
SS
No.1
No.2
No.3
SS
No.1
No.2
No.3
SS
No.1
No.2
No.3
SS
No.1
No.2
No.3
SS
No.1
No.2
No.3
SS
No.1
No.2
No.3
SS
No.1
No.2
No.3
SS
No.1
No.2
No.3
SS
No.1
No.2
No.3
SS
No.1
No.2
No.3
SS
No.1
No.2
No.3
SS
No.1
No.2
No.3
SS
No.1
No.2
No.3
SS
No.1
No.2
No.3
SS
No.1
No.2
No.3
2x6
2x8
160
2x10
2x12
2x4
2x6
2x8
170
2x10
2x12
2x4
2x6
2x8
2x10
2x12
6-4
6-0
5 - 11
4-8
5 - 11
5-9
5-5
4-6
6-2
5 - 11
5-7
4-2
5-9
5-7
5-7
4-6
5-8
5-5
5-3
3 - 11
5-3
5-2
4 - 11
3 - 10
5-6
5-3
4-9
3-6
5-2
5-0
5-0
3 - 10
5-3
5-1
4 - 10
3-6
4 - 11
4 - 10
4-7
3-5
5-2
4 - 11
4-3
3-2
4 - 10
4-8
4-8
3-5
4 - 10
4-6
4-3
3-1
4-6
4-5
4-1
3-0
4-9
4-6
3-9
2-9
4-5
4-2
4-2
3-0
10 - 8
10 - 3
10 - 0
7-5
10 - 0
9-9
9-2
7-3
10 - 6
10 - 0
9-6
6-8
9-9
9-6
9-6
7-3
9-6
9-2
8-9
6-3
8 - 11
8-8
8-3
6-0
9-4
8 - 11
7 - 11
5-7
8-8
8-6
8-6
6-0
8 - 11
8-4
7-9
5-7
8-4
8-1
7-6
5-5
8-8
8-4
7-1
5-0
8-1
7-8
7-8
5-5
8-2
7-3
6-9
4 - 10
7-7
7-1
6-6
4-9
8-0
7-5
6-2
4-4
7-5
6-8
6-8
4-9
15 - 0
14 - 4
13 - 11
10 - 1
13 - 11
13 - 7
12 - 10
9-9
14 - 8
13 - 11
13 - 1
9-0
13 - 7
13 - 2
13 - 2
9-9
13 - 4
12 - 9
11 - 11
8-5
12 - 5
12 - 1
11 - 5
8-1
13 - 0
12 - 5
10 - 9
7-6
12 - 1
11 - 9
11 - 9
8-1
12 - 4
11 - 4
10 - 7
7-6
11 - 6
11 - 2
10 - 2
7-3
12 - 1
11 - 6
9-7
6-8
11 - 3
10 - 5
10 - 5
7-3
11 - 3
9-9
9-2
6-6
10 - 6
9-7
8 - 10
6-4
11 - 1
10 - 1
8-3
5 - 10
10 - 3
9-0
9-0
6-4
20 - 5
19 - 6
19 - 0
13 - 3
19 - 0
18 - 5
17 - 4
12 - 9
20 - 0
19 - 0
16 - 9
11 - 7
18 - 5
17 - 11
17 - 11
12 - 9
18 - 1
17 - 0
15 - 9
10 - 11
16 - 9
16 - 4
15 - 2
10 - 6
17 - 8
16 - 9
13 - 8
9-7
16 - 4
15 - 6
15 - 6
10 - 6
16 - 8
14 - 11
13 - 10
9-8
15 - 6
14 - 8
13 - 4
9-4
16 - 4
14 - 11
12 - 1
8-6
15 - 1
13 - 7
13 - 7
9-4
15 - 2
12 - 9
11 - 11
8-4
14 - 2
12 - 7
11 - 5
8-1
14 - 10
12 - 9
10 - 5
7-5
13 - 9
11 - 8
11 - 8
8-1
25 - 1
24 - 2
23 - 4
16 - 4
23 - 8
23 - 2
22 - 1
15 - 9
24 - 8
23 - 8
21 - 7
14 - 5
23 - 2
22 - 8
22 - 8
15 - 9
22 - 10
21 - 4
19 - 8
13 - 4
21 - 6
20 - 11
18 - 10
12 - 10
22 - 5
21 - 6
17 - 6
11 - 10
21 - 0
19 - 3
19 - 3
12 - 10
21 - 5
18 - 7
17 - 2
11 - 9
20 - 0
18 - 2
16 - 5
11 - 4
21 - 0
19 - 1
15 - 4
10 - 6
19 - 5
16 - 10
16 - 10
11 - 4
19 - 6
15 - 9
14 - 7
10 - 1
18 - 1
15 - 5
14 - 0
9 - 10
19 - 1
16 - 2
13 - 1
9-1
17 - 8
14 - 4
14 - 4
9 - 10
1
Maximum Allowable Rafter Span (ft-in.)
6 - 11
6-8
6-6
5-5
6-6
6-4
6-0
5-3
6-9
6-6
6-2
4 - 10
6-4
6-2
6-2
5-3
6-2
5 - 11
5 - 10
4-7
5 - 10
5-8
5-4
4-5
6-1
5 - 10
5-6
4-1
5-8
5-6
5-6
4-5
5-9
5-7
5-5
4-1
5-5
5-3
5-0
4-0
5-8
5-5
5-0
3-8
5-3
5-2
5-2
4-0
5-4
5-1
4 - 11
3-7
5-0
4 - 10
4-7
3-6
5-3
5-0
4-4
3-2
4 - 10
4-9
4-9
3-6
11 - 10
11 - 4
11 - 0
8-9
11 - 0
10 - 9
10 - 2
8-6
11 - 7
11 - 0
10 - 5
7 - 10
10 - 9
10 - 5
10 - 5
8-6
10 - 6
10 - 1
9 - 10
7-3
9 - 10
9-7
9-1
7-1
10 - 4
9 - 10
9-4
6-6
9-7
9-4
9-4
7-1
9 - 10
9-5
9-2
6-6
9-2
8 - 11
8-5
6-4
9-7
9-2
8-3
5 - 10
8 - 11
8-8
8-8
6-4
9-0
8-6
7 - 11
5-8
8-5
8-2
7-8
5-6
8-9
8-5
7-2
5-1
8-2
7-9
7-9
5-6
16 - 7
15 - 10
15 - 6
11 - 11
15 - 6
15 - 1
14 - 2
11 - 7
16 - 3
15 - 6
14 - 8
10 - 7
15 - 1
14 - 8
14 - 8
11 - 7
14 - 9
14 - 1
13 - 9
9 - 10
13 - 9
13 - 4
12 - 7
9-7
14 - 5
13 - 9
12 - 9
8-9
13 - 4
13 - 0
13 - 0
9-7
13 - 8
13 - 1
12 - 6
8-9
12 - 9
12 - 5
11 - 9
8-6
13 - 4
12 - 9
11 - 3
7-9
12 - 5
12 - 1
12 - 1
8-6
12 - 6
11 - 7
10 - 9
7-7
11 - 8
11 - 4
10 - 4
7-4
12 - 3
11 - 8
9-9
6-9
11 - 4
10 - 7
10 - 7
7-4
22 - 5
21 - 7
21 - 2
15 - 9
21 - 2
20 - 7
19 - 4
15 - 3
22 - 0
21 - 2
20 - 0
13 - 9
20 - 7
20 - 0
20 - 0
15 - 3
20 - 1
19 - 2
18 - 8
12 - 11
18 - 8
18 - 2
17 - 1
12 - 6
19 - 8
18 - 8
16 - 4
11 - 4
18 - 2
17 - 7
17 - 7
12 - 6
18 - 7
17 - 9
16 - 7
11 - 5
17 - 3
16 - 10
15 - 10
11 - 0
18 - 2
17 - 3
14 - 4
10 - 0
16 - 10
16 - 3
16 - 3
11 - 0
16 - 11
15 - 3
14 - 2
9 - 10
15 - 9
15 - 0
13 - 7
9-6
16 - 6
15 - 3
12 - 3
8-8
15 - 4
13 - 10
13 - 10
9-6
26-0†
26-0†
25 - 9
19 - 8
25 - 9
25 - 2
24 - 0
18 - 11
26-0†
25 - 9
24 - 5
17 - 3
25 - 2
24 - 8
24 - 8
18 - 11
24 - 9
23 - 10
22 - 11
15 - 10
23 - 5
22 - 11
21 - 10
15 - 4
24 - 4
23 - 5
21 - 2
14 - 1
22 - 11
22 - 5
22 - 5
15 - 4
23 - 4
22 - 1
20 - 9
13 - 11
22 - 0
21 - 7
19 - 10
13 - 6
22 - 11
22 - 0
18 - 5
12 - 5
21 - 7
20 - 3
20 - 3
13 - 6
21 - 8
18 - 11
17 - 6
12 - 0
20 - 2
18 - 7
16 - 9
11 - 7
21 - 3
19 - 6
15 - 7
10 - 8
19 - 8
17 - 2
17 - 2
11 - 7
6-7
6-4
6-2
5-0
6-2
6-0
5-8
4 - 10
6-6
6-2
5 - 10
4-6
6-0
5 - 10
5 - 10
4 - 10
5 - 11
5-8
5-6
4-3
5-6
5-5
5-1
4-1
5-9
5-6
5-2
3-9
5-5
5-3
5-3
4-1
5-6
5-3
5-2
3-9
5-2
5-0
4-9
3-8
5-5
5-2
4-7
3-4
5-0
4 - 11
4 - 11
3-8
5-1
4 - 10
4-7
3-4
4-9
4-8
4-5
3-3
5-0
4-9
4-0
3-0
4-8
4-6
4-6
3-3
11 - 3
10 - 9
10 - 6
8-1
10 - 6
10 - 3
9-8
7 - 10
11 - 0
10 - 6
9 - 11
7-3
10 - 3
9 - 11
9 - 11
7 - 10
10 - 0
9-7
9-4
6-9
9-4
9-1
8-7
6-6
9 - 10
9-4
8-7
6-0
9-1
8 - 10
8 - 10
6-6
9-4
8 - 11
8-5
6-0
8-8
8-6
8-0
5 - 10
9-1
8-8
7-7
5-5
8-6
8-3
8-3
5 - 10
8-6
7 - 10
7-4
5-3
8-0
7-8
7-0
5-1
8-4
8-0
6-7
4-8
7-9
7-2
7-2
5-1
15 - 9
15 - 0
14 - 8
10 - 11
14 - 8
14 - 3
13 - 5
10 - 7
15 - 5
14 - 8
13 - 10
9-8
14 - 3
13 - 10
13 - 10
10 - 7
14 - 0
13 - 4
13 - 0
9-1
13 - 0
12 - 8
12 - 0
8-9
13 - 8
13 - 0
11 - 8
8-1
12 - 8
12 - 4
12 - 4
8-9
13 - 0
12 - 4
11 - 6
8-1
12 - 1
11 - 9
11 - 0
7 - 10
12 - 8
12 - 1
10 - 4
7-2
11 - 9
11 - 3
11 - 3
7 - 10
11 - 10
10 - 7
9 - 11
7-0
11 - 1
10 - 5
9-6
6-9
11 - 7
10 - 11
8 - 11
6-3
10 - 9
9-8
9-8
6-9
21 - 6
20 - 6
20 - 0
14 - 5
20 - 0
19 - 5
18 - 3
13 - 11
21 - 1
20 - 0
18 - 4
12 - 7
19 - 5
18 - 10
18 - 10
13 - 11
19 - 0
18 - 1
17 - 3
11 - 10
17 - 8
17 - 2
16 - 2
11 - 5
18 - 7
17 - 8
14 - 10
10 - 5
17 - 2
16 - 8
16 - 8
11 - 5
17 - 7
16 - 4
15 - 1
10 - 5
16 - 4
15 - 11
14 - 6
10 - 1
17 - 2
16 - 4
13 - 1
9-3
15 - 11
14 - 10
14 - 10
10 - 1
16 - 0
13 - 11
12 - 11
9-0
14 - 11
13 - 8
12 - 5
8-9
15 - 8
13 - 11
11 - 3
8-0
14 - 6
12 - 8
12 - 8
8-9
26-0†
25 - 2
24 - 8
17 - 10
24 - 8
24 - 2
23 - 0
17 - 2
25 - 8
24 - 8
22 - 11
15 - 9
24 - 2
23 - 7
23 - 7
17 - 2
23 - 9
22 - 8
21 - 6
14 - 6
22 - 5
21 - 11
20 - 8
14 - 0
23 - 4
22 - 5
19 - 2
12 - 10
21 - 11
21 - 2
21 - 2
14 - 0
22 - 4
20 - 4
18 - 9
12 - 9
21 - 1
20 - 0
18 - 0
12 - 4
21 - 11
21 - 0
16 - 8
11 - 4
20 - 5
18 - 4
18 - 4
12 - 4
20 - 7
17 - 2
15 - 11
11 - 0
19 - 1
16 - 10
15 - 3
10 - 7
20 - 1
17 - 8
14 - 3
9 - 10
18 - 7
15 - 7
15 - 7
10 - 7
See Table 3.26M footnotes.
† Spans are limited to 26 feet in length.
1
Copyright © American Wood Council. Downloaded/printed pursuant to License Agreement. No reproduction or transfer authorized.
AMERICAN WOOD COUNCIL
25
WOOD FRAME CONSTRUCTION MANUAL
WFCM
327
Footnotes to Table 3.26M
1
Tabulated rafter spans (horizontal projection) in Table 3.26M are based on a 12:12 roof pitch and L/180 deflection limit. For other roof
pitches and deflection criteria, multiply tabulated values by the following adjustments.
3
†
Spans are limited to 26 feet in length.
PRESCRIPTIVE DESIGN
Copyright © American Wood Council. Downloaded/printed pursuant to License Agreement. No reproduction or transfer authorized.
AMERICAN WOOD COUNCIL
26
Polling Question
4. Roof rafters designed for wind loads are based on
which of the following?
a) Deflection limit
b) Roof pitch
c) Lumber grade
d) All of the above
e) a) and b) only
27
WFCM WB
Connections (cont’d)
Table W4.9 Alternative proprietary connectors every rafter/stud with the following minimum
capacities from Tables 3.4 and 3.4C. Design for 16" o.c. rafter spacing which will be conservative
for 12" o.c. rafter spacing for the vaulted ceiling.
Loadbearing Non-Loadbearing
Building Wall Elevation
Wall Height
Loadbearing Walls - Tabulated minimum uplift connection
capacity (Table 3.4)
Interior framing adjustment (Table 3.4 Footnote 1)
Roof dead load reduction (Table 3.4 Footnote 3)
W Non-Loadbearing Walls - Tabulated minimum uplift
i connection capacity (Table 3.4C and figure below)
n Connector location (Table 3.4C, Footnote 1)
d
WSP minimum (Table 3.4C, Footnotes 2-4)
Required Minimum Uplift Capacity of proprietary connector
= Tabulated minimum capacity with Adjustments
Required Minimum Lateral Capacity – rafter/truss to wall
(Table 3.4)
Tabulated Lateral Capacity – top and bottom plate to stud
(Table 3.5)
Spacing multiplier (Table 3.5 Footnote 2)
Required Minimum Lateral Capacity = tabulated capacity x
Adjustments
Tabulated Minimum Shear Parallel to Ridge Capacity
(R=W/L=0.8) (Table 3.4)
Tabulated Minimum Shear Perpendicular to Ridge Capacity
(R=L/W=1.25)
Shear connection adjustment (Table 3.4 Footnote 4)
Required Minimum Shear Capacity
2-2
2-1
3-B
3-A
9'
9'
9.3'
6.2'
486 lbs
n/a
1.0
n/a
0
n/a
n/a
671 lbs
n/a
Outside wall face
n/a
40/20 (19/32"
nominal)*
486 lbs
537 lbs*
224 lbs
n/a
n/a
159 plf** 141 plf
n/a
1.33
1.33
n/a
211 lbs
188 lbs
94 lbs
n/a
n/a
148 lbs
0.92
0.92
87 lbs
136 lbs
* To use 7/16" roof sheathing thickness, reduce outlooker overhang span to 19.2". Uplift = 537 lbs.
** For 3-B, maximum load based on stud length at the ridge. Loads will decrease as stud length decreases.
28
WOOD FRAME CONSTRUCTION MANUAL
Table 3.4C
Exposure B
Rake Overhang Outlooker Uplift Connection
Requirements
Wind Speed
3-second gust (mph)
(See Figure 1.1)
Overhang
Span
(in.)
12
181
WFCM
90
95
100
105
110
115
120
130
140
150
160
170
180
195
16
Outlooker
Spacing
(in.)
12
16
24
12
86
115
172
108
96
128
192
121
104
139
208
131
117
156
234
147
129
172
257
162
140
187
281
177
153
204
306
192
180
240
359
226
208
278
416
262
239
319
478
300
272
363
544
342
308
411
616
387
344
459
688
432
404
539
508
19.2
16
24
12
144
216
128
161
241
142
175
262
155
196
295
174
216
323
191
235
353
208
256
385
227
301
452
266
349
523
309
401
601
354
456
683
403
516
774
4562
576
5102
6772
5993
16
170
190
207
231
254
278
302
355
411
472
537
2
6802
-
7983
7484
-
24
255
284
310
347
381
416
453
533
617
708
806
6082
-
12
159
178
194
217
238
260
283
333
3862
4433
5034
5704
6374
2
3
4
4
4
16
213
237
259
289
318
347
378
444
24
319
355
389
434
476
520
567
2
665
514
771
2
590
-
671
-
760
-
849
-
-
1
Uplift connection load based on connector located on inside face of 2x4 end wall and is not applicable for connector located
on inside face of walls with framing members larger than 2x4. It shall be permitted to locate the connector on the outside
face of walls with 2x4 and larger framing.
2
Wood structural panel sheathing with minimum 24/16 span rating required (minimum 7/16" nominal thickness).
3
Wood structural panel sheathing with minimum 32/16 span rating required (minimum 15/32" nominal thickness).
4
Wood structural panel sheathing with minimum 40/20 span rating required (minimum 19/32" nominal thickness).
Minimum 2x4 blocking between outlookers
with same depth as outlooker depth,
Sheathing nailing to outlooker,
(2) 8d Common toe-nails each
blocking between outlookers, and end of blocking to outlooker
outlooker rim in accordance with
Table 3.10 for Rake Overhang
Wood strucural panel sheathing with minimum 24/0 span rang
and minimum 3/8" nominal thickness in accordance with Table 3.12A
Strength Axis Applied Perpendicular to Supports (i.e. strength axis
perpendiular to endwall, roof trusses or raers) except as otherwise
noted in Table 3.4C footnotes 2, 3 and 4
Perimeter Edge Zone nailing in
accordance with Table 3.10
L
Overhang
span not
to exceed
lesser of
L/2 or 2'
Minimum 2x4 outlooker
rim (fly raer) with depth not less than
outlooker depth, (3) 16d Common,
end nailed
(3) 16d Common,
end nailed
Upli connector
Minimum 2x4 outlooker
with depth not greater than
roof truss chord depth or raer depth
1
Gable endwall 2x4 framing
Copyright © American Wood Council. Downloaded/printed pursuant to License Agreement. No reproduction or transfer authorized.
AMERICAN WOOD COUNCIL
29
PRESCRIPTIVE DESIGN
24
3
Uplift Connection Load (lbs)1
174
WFCM
PRESCRIPTIVE DESIGN
Table 3.4
Exposure B
Rafter/Truss Framing to Wall Connection
Requirements for Wind Loads (Cont.)
(Dead Load Assumptions: Roof/Ceiling Assembly DL = 15 psf)
Wind Speed
3-second gust
(mph)
(See Figure 1.1)
Rafter/
Truss
Spacing
(in.)
Roof
Span
(ft)
150
160
170
180
195
1
Required Capacity of Connection (lbs.)
U2,3,5
L
S4
U2,3,5
L
S4
U2,3,5
L
S4
U2,3,5
L
S4
U2,3,5
L
S4
148
78R
168
88R
190
100R
212
112R
12
147
177
209
243
297
249
131R
16
176
213
252
293
360
20
206
249
295
344
423
12
24
236
286
339
395
486
28
266
323
383
447
549
32
296
359
427
498
612
36
326
396
470
549
676
197
103R
224
118R
253
133R
283
149R
333
175R
12
195
236
278
324
397
16
235
284
336
391
480
20
275
332
394
459
563
16
24
315
381
452
527
648
28
355
430
510
595
732
32
395
479
569
664
817
36
435
528
627
732
901
236
124R
269
141R
303
159R
340
179R
399
210R
12
235
283
334
388
476
16
282
340
403
469
576
20
330
399
472
551
676
19.2
24
378
457
542
632
777
28
426
516
612
714
878
474
575
683
797
980
32
36
522
634
753
879
1081
295
155R
336
177R
379
199R
425
223R
499
262R
12
293
353
418
486
595
16
352
426
504
586
719
20
412
498
591
688
845
24
24
472
572
678
790
971
28
532
645
765
893
1098
32
592
719
853
996
1225
36
653
792
941
1098
1352
= Connector uplift load.
U
= Connector lateral load (Perpendicular to the wall).
L
= Connector shear load (Parallel to the wall).
S
R
= L/W for wind perpendicular to the ridge and W/L for wind parallel to the ridge, where W is the building width and L is the building length.
1
Tabulated uplift and lateral loads shall be permitted to be multiplied by 0.75 and 0.92, respectively, for framing not located within 8 feet of
building corners.
2
Tabulated uplift loads assume a reduced roof and ceiling assembly dead load of 9 psf (0.6 x 15 psf = 9 psf).
Tabulated uplift loads are specified for roof-to-wall connections. When calculating uplift loads for wall-to-wall or wall-to-foundation
connections, tabulated uplift values shall be permitted to be reduced by 73 plf (0.60 x 121 plf) for each full wall above.
Shear connection values shall be multiplied by the following adjustments:
4
Wall Height
8'
10'
Top Plate to
Adjustment
Roof
Ridge Height
Factor
Pitch
0' (flat)
0.40
0.50
≤6:12
5'
0.65
0.75
10'
0.90
1.00
5'
0.65
0.75
10'
0.90
1.00
>6:12
15'
1.15
1.25
20'
1.40
1.50
For jack rafter uplift connections, use a roof span equal to twice the jack rafter length. The jack rafter length includes the overhang length
5
and the jack span.
Copyright © American Wood Council. Downloaded/printed pursuant to License Agreement. No reproduction or transfer authorized.
3
AMERICAN WOOD COUNCIL
30
WFCM WB
Connections (cont’d)
Sheathing and Cladding Attachment (WFCM 3.2.5)
Roof Sheathing (WFCM 3.2.4.1)
Choose Roof Sheathing Nail Spacing from Table 3.10A
Three second gust wind speed (700 yr) and exposure category: ................ 160 mph Exp. B
Rafter/Truss Spacing:..................................................................................
16 in.
Sheathing Type: .......................................................................................... 7/16" WSP G=0.5
Table W4.10 Roof Sheathing
Nail Spacing to Resist
Suction Loads
Nail Spacing
8d Common Nails
DF/SP
G=0.49
HF/SPF
G=0.42
E/F
E/F
4' Perimeter Edge Zone
6"/6"*
6"/6"
Interior Zones
6"/12"
6"/6"
Rafter/Truss Framing
Location – Edge (E) / Field (F)
Outlooker Detail (WFCM Fig. 2.1g)
Lookout Block Overhang
NP**
NP**
* Nail spacing can be 6"/12" over vaulted ceiling with
rafters at 12" o.c.
** Not permitted since overhang span exceeds 9".
Outlooker detail per WFCM Figure 2.1g required.
Lookout Block Detail (WFCM Fig. 2.1h)
Table W4.11 Roof Sheathing
Ring Shank Nail Spacing to
Resist Suction Loads
Nail Spacing
RSRS-03
DF/SP
G=0.49
HF/SPF
G=0.42
E/F
E/F
4' Perimeter Edge Zone*
6"/6"**
6"/6"
Interior Zones
6"/12"
6"/12"
Rafter/Truss Framing
Location – Edge (E) / Field (F)
NP***
NP***
Lookout Block Overhang
* Nail spacing can be 6"/12" over vaulted ceiling with
rafters at 12" o.c.
** Sheathing thickness of 19/32" would allow 6"/12"
nail spacing and 24" outlooker span.
*** Not permitted since overhang span exceeds 9".
Outlooker detail per WFCM Figure 2.1g required.
31
WOOD FRAME CONSTRUCTION MANUAL
Table 3.10A
WFCM
197
Exposure B
Roof Sheathing Attachment Requirements for Wind
Loads (7/16", PANEL G=0.50)
(Prescriptive Alternative to Table 3.10)
Wind Speed 3-second gust (mph)
(See Figure 1.1)
90
95
100
105
110
115
120
130
140
150
160
170
180
195
STRUCTURAL SHEATHING
E
Sheathing Location1
0.49
Interior Zone
0.42
0.49
Perimeter Edge Zone
0.42
Gable Endwall Rake or
Rake Truss with up to
9" Rake Overhang
E
F
E
Rafter/Truss
Spacing (in.)
12
16
19.2
24
12
16
19.2
24
12
16
19.2
24
12
16
19.2
24
F
E
F
E
F
E
F
E
F
E
F
E
F
E
F
E
F
E
F
E
F
E
F
12
12
12
6
12
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
12
12
6
6
12
6
6
6
6
6
6
6
6
6
6
6
6
6
4
6
6
12
6
6
6
6
6
6
4
6
6
Maximum Nail Spacing for 8d Common Nails, or 10d Box Nails (inches, o.c.) 2 , 4
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
12
12
12
12
12
12
12
12
12
12
12
6
12
12
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
12
12
12
12
12
12
12
12
12
12
12
6
12
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
12
12
12
12
12
12
12
6
12
12
6
6
12
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
4
12
12
12
12
12
12
12
6
12
6
6
6
6
6
6
4
6
6
6
6
6
6
6
6
6
6
6
12
12
12
12
12
12
6
6
12
6
6
6
6
4
6
6
4
6
6
6
6
6
6
6
6
6
6
6
12
12
12
6
12
6
6
6
12
6
6
6
6
6
6
6
6
6
6
6
6
6
Exceeds capacity of 7/16" sheathing
6
6
4
6
6
4
6
4
4
6
4
4
6
4
4
6
4
4
Exceeds capacity of 7/16" sheathing
3
4
4
4
4
3
0.49
-
6
6
6
6
6
6
6
6
6
6
6
6
4
4
0.42
-
6
6
6
6
6
6
6
6
6
4
4
4
3
3
2
3
2
3
2
3
2
3
BOARD SHEATHING
Sheathing Size
1x6 or 1x8 Sheathing
1x10 or Larger Sheathing
Rafter/Truss
Spacing (in.)
12-19.2
12-19.2
Minimum Number of 8d Common Nails Per Support4
2
3
2
3
2
3
2
3
2
3
2
3
2
3
2
3
2
3
2
3
E
F
-
1
For roof sheathing within 4 feet of the perimeter edge of the roof, including 4 feet on each side of the roof peak, the 4 foot perimeter edge zone attachment requirements
shall be used.
For wind speeds greater than 130 mph, blocking is required which transfers lateral load to two additional joists (3 joists total).
See Table 3.10 for other fastener and sheathing combinations.
Tabulated values for 8d common and 10d box nails are applicable to carbon steel nails (bright or galvanized).
2
3
4
3
Nail spacing at panel edges (in.)
Nail spacing at intermediate supports in the panel field (in.)
Copyright © American Wood Council. Downloaded/printed pursuant to License Agreement. No reproduction or transfer authorized.
AMERICAN WOOD COUNCIL
32
PRESCRIPTIVE DESIGN
Rafter/Truss
Framing
Specific
Gravity, G
F
WOOD FRAME CONSTRUCTION MANUAL
Table 3.10
Sheathing Location1
Rafter
/Truss
Spacing
(in.)
12
Interior Zone
19.2
24
12
16
Perimeter Edge Zone
19.2
24
Gable Endwall Rake or
Rake Truss with up to 9"
Rake Overhang
95
90
100
105
110
115
120
130
140
150
160
170
180
195
47
24
16
12
62
31
21
16
74
37
25
19
93
47
31
24
87
44
29
22
116
58
39
29
139
70
47
35
174
87
58
44
53
27
18
14
70
35
24
18
84
42
28
21
105
53
35
27
99
50
33
25
132
66
44
33
158
79
53
40
198
99
66
50
60
30
20
15
79
40
27
20
95
48
32
24
119
60
40
30
112
56
38
28
149
75
50
38
179
90
60
45
223
112
75
56
67
34
23
17
89
45
30
23
107
54
36
27
133
67
45
34
125
63
42
32
167
84
56
42
200
100
67
50
250
125
84
63
78
39
26
20
104
52
35
26
125
63
42
32
156
78
52
39
147
74
49
37
196
98
66
49
235
118
79
59
294
147
98
74
131
Fastener Spacing
Panel
Edges
(in.)
Interm.
Supports
(in.)
6
6
4
3
6
6
4
3
6
6
4
3
6
6
4
3
6
6
4
3
6
6
4
3
6
6
4
3
6
6
4
3
12
6
4
3
12
6
4
3
12
6
4
3
12
6
4
3
12
6
4
3
12
6
4
3
12
6
4
3
12
6
4
3
Fastener Spacing
(in.)
6
4
3
Uplift Load per Nail (lbs)
17
9
6
5
23
12
8
6
27
14
9
7
34
17
12
9
32
16
11
8
42
21
14
11
50
25
17
13
63
32
21
16
4
8d common
10d box4
RSRS-035
21
11
7
6
28
14
10
7
33
17
11
9
41
21
14
11
39
20
13
10
52
26
18
13
62
31
21
16
78
39
26
20
23
12
8
6
31
16
10
8
37
19
12
9
46
23
16
12
43
22
15
11
57
29
19
15
68
34
23
17
85
43
29
22
25
13
9
7
34
17
11
9
40
20
14
10
50
25
17
13
47
24
16
12
63
32
21
16
75
38
25
19
94
47
32
24
28
14
9
7
37
19
12
9
44
22
15
11
55
28
19
14
51
26
17
13
68
34
23
17
82
41
28
21
102
51
34
26
30
15
10
8
40
20
14
10
48
24
16
12
59
30
20
15
56
28
19
14
74
37
25
19
89
45
30
23
111
56
37
28
35
18
12
9
47
24
16
12
56
28
19
14
70
35
24
18
66
33
22
17
87
44
29
22
105
53
35
27
131
66
44
33
41
21
14
10
54
27
18
14
65
33
22
17
81
41
27
21
76
38
26
19
101
51
34
26
121
61
41
31
152
76
51
38
Uplift Load per Nail (lbs)
28
31
35
38
42
46
50
59
68
78
88
100
112
19
21
23
26
28
31
33
39
45
52
59
67
75
88
14
16
18
19
21
23
25
30
34
39
44
50
56
66
2, 3
Fastener Uplift Capacity (lbs)
7/16
15/32
19/32
3/8
Sheathing Thickness (in.)
Framing Member G
19
10
7
5
25
13
9
7
30
15
10
8
37
19
13
10
35
18
12
9
47
24
16
12
56
28
19
14
70
35
24
18
23/32
0.42 0.49 0.42 0.49 0.42 0.49 0.42 0.49 0.42 0.49
70
91
68
100
67
98
63
92
58
86
84
91
101
91
82
99
118
106
81
99
120
114
77
99
114
135
73
99
108
135
For roof sheathing within 4 feet of the perimeter edge of the roof, including 4 feet on each side of the roof peak, the 4-foot perimeter edge
zone attachment requirements shall be used.
Minimum capacity of withdrawal and fastener head pull-through is tabulated.
Tabulated values include a load duration factor adjustment, CD=1.6.
Tabulated values for 8d common nails and 10d box nails are applicable to carbon steel nails (bright or galvanized).
Tabulated values for RSRS-03 nails are applicable to carbon steel (bright or galvanized) or stainless steel nails.
Copyright © American Wood Council. Downloaded/printed pursuant to License Agreement. No reproduction or transfer authorized.
AMERICAN WOOD COUNCIL
33
3
PRESCRIPTIVE DESIGN
16
2
3
4
5
Exposure B
Roof Sheathing Attachment Requirements for Wind
Loads
Wind Speed 3-second gust (mph)
(See Figure 1.1)
1
WFCM
195
WFCM WB
Framing and Connection Summary
Table W4.12 Gable Wall and Roof Framing and Connection Summary
Wall
2-2
2-1
3-B
3-A
No. 3/Stud
No. 3/Stud
Stud Grade and Size
2x6
2x6
Stud Length
9.3'
6.2'
Stud Spacing
16"
16"
Roof to Wall Lateral/Shear
3-8d comm.
3-8d comm.
211 lbs
188 lbs
Roof to Wall Uplift
4-8d comm.
4-8d comm.
537 lbs*
537 lbs*
Plate to Stud Lateral
2-16d comm. 2-16d comm. 2-16d comm. 2-16d comm.
* 19/32" WSP sheathing and 24" outlooker requires 671 lbs uplift connector.
Table W4.13 Roof and Ceiling Framing and Connection Summary
Vaulted
Attic Space
Ceiling
Rafter Grade and Size
No. 2 2x10
SS 2x10*
Rafter Spacing
16"
12"
Floor/Ceiling Joist Grade & Size No. 2 2x10**
No. 2 2x8
Floor/Ceiling Joist Spacing
16"
12"
Floor/Ceiling Joist Length
16'
21'
Rafter to Ceiling Joist Nailing
5-16d comm. 6-16d comm.
Collar Tie/Ridge Strap Nailing
4-8d comm.
3-8d comm.
* Southern Pine requires DSS grade. Hem-Fir and SPF require 2x12 No. 2.
** Southern Pine requires 2x12 No. 2.
Table W4.14 Roof Sheathing Nail
Spacing to Resist Suction Loads
Panel Thickness and
Nail Spacing
7/16" & 8d 19/32" &
WSP with G=0.50
Commons RSRS-03
Location – Edge (E) / Field (F)
E/F
E/F
4' Perimeter Edge Zone
6"/6"
6"/12"*
Interior Zones
6"/6"
6"/12"
Gable Endwall Outlooker Span
19.2"
24"
* HF and SPF framing require 6"/6" nail spacing.
34
Polling Question
ϱ͘Per WFCM prescriptive requirements, gable-end rake
overhangs with lookout blocks are limited to what
span?
a) 6 inches
b) 9 inches
c) 12 inches
d) 24 inches
35
WFCM WB
SECOND STORY DESIGN
Wall Framing .......................................................34
Wall Sheathing .....................................................39
Floor Framing ......................................................43
Floor Sheathing ....................................................43
Connections ..........................................................44
Wall Detailing Summary .....................................50
36
WFCM WB
Wall Sheathing
Sheathing and Cladding (WFCM 3.4.4.1)
Choose Exterior Wall Sheathing OR Cladding from Tables 3.13A and 3.13B, respectively
Three second gust wind speed (700 yr) and Exposure category: ................
160
mph Exp. B
Sheathing Type (wood structural panels, fiberboard, board, hardboard): ... WSP
Strength Axis to Support (Parallel or Perpendicular): ................................ Parallel
Stud Spacing: ..............................................................................................
16 in.
Minimum Panel Thickness to resist suction loads: ..................................... 15/32 in.
LFH = 24 ft
2-2 (North) Elevation
LFH = 22 ft
2-1 (South) Elevation
LFH = 32 ft
2-B (East) Elevation
LFH = 29 ft
2-A (West) Elevation
37
WFCM WB
Wall Sheathing (cont’d)
Exterior Segmented Shear Walls (WFCM 3.4.4.2)
Choose Exterior Segmented Shear Wall Length from Table 3.17A-D
Wall Height: ................................................................................................
Number of Stories Braced (per 3.1.3.1 and table footnotes):......................
9
1
Three second gust wind speed (700 yr) and Exposure category: ................
Maximum shear wall aspect ratio for wind (Table 3.17D Footnote 4): ......
Minimum shear wall segment length (Wall height/aspect ratio) (9 ft/3.5):
160 mph Exp. B
3.5:1
2.6 ft
Seismic Design Category: ...........................................................................
Roof and Attic Dead Load ..........................................................................
NOTE: Dead load has been increase to account for partial attic.
Maximum shear wall aspect ratio for seismic (Table 3.17D Footnote 4): ..
Minimum shear wall segment length (Wall height/aspect ratio) (9 ft/3.5):
D1
25 psf
3.5:1
2.6 ft
Minimum WSP sheathing thickness (per WFCM 3.4.4.2): ........................ 3/8
NOTE: Minimum WSP thickness for suction controls
Minimum gypsum thickness (per WFCM 3.4.4.2): .................................... 1/2
NOTE: Aspect ratio limit of 1.5:1 unblocked: 2:1 blocked
Maximum stud spacing (per WFCM 3.4.4.2): ........................................... 16
8d common nails
@ 6” OC on
panel perimeter
8d common
nails @ 12” OC
in field
ft
in.
in.
in.
5d cooler nails
@ 7” OC on
panel perimeter
5d cooler nails
@ 10” OC in
field
3/8” wood
structural panel
continuous
height over wall
plates
Panel exterior
1/2” gypsum
wallboard on
interior
Panel interior
exterior
WFCM 3.4.4.2 “Standard” Shear Wall
WFCM Table 3.17D Footnote 4. The aspect ratio is permitted to be increased to a maximum value
of 3.5:1 provided the unit shear capacity and sheathing type adjustment factor are adjusted in
accordance with SDPWS Section 4.3.3.4.1 Exception 1 for wood structural panel shear walls...
2015 SDPWS 4.3.3.4.1 Exception 1. Where nominal shear capacities of all wood
structural panel shear walls with aspect ratios (h/bs) greater than 2:1 are multiplied
by 2bs/h for design, shear distribution to individual full-height wall segments shall
be permitted to be taken as proportional to the shear capacities of individual full
height wall segments used in design.
38
WFCM WB
Wall Sheathing (cont’d)
Exterior Segmented Shear Walls (WFCM 3.4.4.2)
Table W5.5 Calculation of Exterior Segmented Shear Wall Lengths and Nailing Requirements
Building Wall Elevation
2-2
2-1
2-B
2-A
Wall Height
Length (L) or Width (W) of Building being Designed
Actual Length of Full Height Sheathing (LFH)
Effective Length of Full Height Sheathing for Seismic (LFH-Eff)
Tabulated Min. Length Full Height Sheathing for Seismic Loads
per Table 3.17C1 (R&C)* L/W = 1.25 (interpolated) (Ls)
Vertical distribution factor adjustment per Table 3.17C
S
e Footnote 2 (Cvd)
i Adjustment for other dead load case per Table 3.17C Footnote 4
s (R&C)** (Cdl)
m WSP Perimeter Edge Nail Spacing – Seismic
i (WFCM 3.4.4.2b + 3.4.4.2.1)
c Sheathing Type Adjustment per Table 3.17D (Csw)
Min. Length Full Ht. Sheathing – Segmented Seismic
LSSW-S = Ls(Csw) (Cdl) (Cvd)
LSSW-S < LFH-Eff
Tabulated Min. Length Full Ht. Sheathing for Wind per
Table 3.17A (R&C) (Lw)
WSP Perimeter Edge Nail Spacing – Wind (WFCM 3.4.4.2a)
W Sheathing Type Adjustment per Table 3.17D (Csw)
i Wall and Roof Height Adjustment (Table 3.17A Footnote 4)
n (CWRH)
d
Min. Length Full Ht. Sheathing–Segmented Wind
LSSW-W = Lw(CWRH)(Csw)
LSSW-W < LFH-Eff
*
**
9'
9'
9'
L=40' L=40' W=32'
9'
W=32'
24'
20'*
22'
18'*
32'
32'
29'
29'
8.8'
8.8'
8.8'
8.8'
0.92
0.92
0.92
0.92
1.42
1.42
1.42
1.42
6"
6"
6"
6"
1.0
1.0
1.0
1.0
11.5'
11.5'
11.5'
11.5'
Ok
Ok
Ok
Ok
10.3'
6"
1.0
10.3'
6"
1.0
12.8'
6"
1.0
12.8'
6"
1.0
0.92
0.92
0.92
0.92
9.5'
9.5'
11.8'
11.8'
Ok
Ok
Ok
Ok
For seismic loads, pPer Table 3.17D Footnote 4, the aspect ratio can exceed 2:1 per SDPWS 4.3.3.4.1
Exception 1 which requires the unit shear capacity to be multiplied by 2bs/h. There are four 3' (b=3) segments
in Walls 2-1 and 2-2, so the aspect ratio adjustment factor is 2bs/h = 2(3)/9 = 0.67. This adjustment only
applies to the 3' segments:
Wall 2-1: 10' + 3'(0.67)(4) = 18'
Wall 2-2: 12' + 3'(0.67)(4) = 20'
Since only 11.5' is required, the two six foot segments work in Wall 2-2. Wall 2-1 will require the two five
foot segments along with at least one more three foot segment.
Since the attic only partially covers the structure and there are no additional walls or partitions, from Table
3.17C3 use Shear Wall Line Beneath category “roof and ceiling” to design the shear walls, then use the
Footnote 4 adjustment to compensate for additional dead load due to attic floor framing. In this case, use
roof/ceiling assembly = 25 psf.
See p.51 and beyond for Tables 3.17A, 3.17D, etc.
39
WFCM WB
Wall Sheathing (cont’d)
Exterior Perforated Shear Walls (WFCM 3.4.4.2)
Using Segmented Shear Wall results from Table W5.5, determine Perforated Shear Wall Lengths using
Table 3.17E
Table W5.6 Calculation of Exterior Perforated Shear Wall Lengths and Nailing Requirements
Building Wall Elevation
2-2
2-1
2-B
2-A
Wall Height
Max. Unrestrained Opening Height
Max. Unrestrained Opening Heights as functions of wall height
Actual Length of Full Height Sheathing (LFH)
Effective Length of Full Height Sheathing (LFH-Eff)
S Length of Wall (LWall)
e Min. Length Full Ht. Sheathing - Segmented Seismic (LSSW-S)
i
Percent Full Height Sheathing (LSSW-S / LWall)
s
m Perforated Length Increase Factor from Table 3.17E (CL)
i Min. Length Full Ht. Sheathing - Perforated Seismic
c LPSW-S = LSSW-S (CL)
LPSW-S < LFH-Eff
Actual Length of Full Height Sheathing (LFH)
Length of Wall (LWall)
W Min. Length Full Height Sheathing - Segmented Wind (LSSW-W)
i Percent Full Height Sheathing (LSSW-W / LWall)
n Perforated Length Increase Factor from Table 3.17E (C )
L
d
Min. Length Full Ht. Sheathing - Perforated Wind
LPSW-W = LSSW-W (CL)
LPSW-W < LFH-Eff
9'
6'-0"
2H/3
24'
20'*
40'
11.5'
29%
1.55
9'
4'-6"
H/2
22'
18'*
40'
11.5'
29%
1.31
9'
0
0
32'
32'
32'
11.5'
36%
1.00
9'
4'-6"
H/2
29'
29'
32'
11.5'
36%
1.27
17.8'
15.1'
11.5'
14.6'
Ok
24'
40'
9.5'
24%
1.62
Ok
22'
40'
9.5'
24%
1.34
Ok
32'
32'
11.8'
37%
1.00
Ok
29'
32'
11.8'
37%
1.27
15.4'
12.7'
11.8'
15.0'
Ok
Ok
Ok
Ok
* Includes a 2b/h reduction for exceeding 2:1 aspect ratio. See Table W5.5 footnote for explanation.
Table W5.7 Top Story Shear Wall Edge Nail Spacing and Wall Length Summary
Building Elevation
2-2
2-1
2-B
2-A
Segmented 6" 11.5' 6" 11.5' 6" 11.5' 6" 11.5'
Seismic
Perforated 6" 17.8' 6" 15.1' 6" 11.5' 6" 14.6'
Wind
Segmented
6"
9.5'
6"
9.5'
6" 11.8' 6" 11.8'
Perforated 6" 15.4' 6" 12.7' 6" 11.8' 6" 15.0'
See shear wall detailing summary tables at the end of this section for a final
comparison of wind vs. seismic results.
40
WFCM WB
Connections (cont’d)
Uplift Connections (WFCM 3.2.2)
Wall Assembly to Wall Assembly (WFCM 3.2.2.2)
Table W5.9 Wall to Wall Uplift Strap Connection from Table A-3.4
Building Wall Elevation
Three second gust wind speed (700 yr) and Exposure category:
2-1
2-2
160 mph Exp. B
Framing Spacing
16 in.
W
32 ft
i Roof Span
n Minimum tabulated number of 8d Common Nails required in each
4
d end of 1-1/4" x 20 gage strap every stud
No Ceiling Assembly nail increase Table A-3.4 Footnote 2
0
Minimum required number of 8d Common Nails in each end of strap
4*
every stud = Tabulated number of nails - Reductions + Increases
*Non-loadbearing wall assemblies (2-A and 2-B) in accordance with Table W5.10 below (3.2.6.3)
Table W5.10 Alternative proprietary connectors every stud with the following minimum capacities
Building Wall Elevation
2-1
2-2
2-A
2-B
Loadbearing Walls - Tabulated minimum uplift connection capacity
486 lbs
n/a
(Table 3.4)
Interior framing adjustment (The 75% uplift factor reduction allowed
n/a
1.0
by Table 3.4 Footnote 1 was not applied)
W
Roof dead load reduction (Table 3.4 Footnote 2) = 0 since the attic
n/a
i
-0 lbs
floor does not cover the entire second floor
n
Wall-to-Wall and Wall-to-Foundation reduction
d
-97 lbs
-97 lbs
(Table 3.4 Footnote 3) = [73 plf x (16" / 12"/ ft ) = 97 lbs]
Non-Loadbearing Walls - Tabulated minimum uplift connection
n/a
671 lbs
capacity (Table 3.4C)
Connector location (Table 3.4C, Footnote 1)
n/a
n/a
WSP minimum (Table 3.4C, Footnotes 2-4)
Required minimum capacity of proprietary connector
= Tabulated minimum capacity with Adjustments
Required number of 8d common nails (Z' = 104 lbs) in each end of
straps on every stud = Required capacity ÷ Z'
n/a
40/20 (19/32"
nominal)*
389 lbs
440 lbs*
4
5 or 6**
* To use 7/16" roof sheathing thickness, reduce outlooker overhang span to 19.2". Tabulated uplift = 537 lbs. Wall
dead load can be deducted from uplift: 537-97=440 or 671-97=574.
** Five nails to resist 440 lbs uplift and 6 nails to resist 574 lbs uplift.
Check Perforated Shear Wall plate anchorage between wall ends
The assumption is that wall plate nailing to floor framing (WFCM 3.2.1.6 and Table 3.1) in addition to the
wind uplift straps (determined above), are sufficient to resist uplift requirements on the plate using the
Perforated Shear Wall Method. See 2015 SDPWS section 4.3.6.4.2.1.
41
WFCM WB
Connections (cont’d)
Uplift Connections (WFCM 3.2.3)
Wall Assembly to Wall Assembly (WFCM 3.2.2.2 and 3.2.3)
Table W5.11 Alternative to metal straps on every stud - wood structural panels to resist wall plate
to wall stud uplift and shear from Table 3.4B
Building Wall Elevation
2-1
2-2
2-A
2-B
Three second gust wind speed (700 yr) and Exposure category
160 mph Exp. B
160 mph Exp. B
32 ft
n/a *
Roof Span
W
i Shear Wall Sheathing Thickness (see shear wall design above)
n
Shear Wall Nailing: size and spacing (panel edges and field)
d
15/32 in.
15/32 in.
8d common @
6"/12"
8d common @
6"/12"
Number of Rows Required at top and bottom of panel edges
2
2
4" **
3" **
Top and Bottom Panel Edge Nail spacing (WFCM Figure 3.2f)
* An engineered approach using 2015 SDPWS to design gable end wall (2-A & 2-B) WSPs to resist
combined uplift and shear is as follows:
1. Uplift calculated in Table W5.10 for outlooker with 19.2" overhang gives 440 lbs and 24"
overhang gives 574 lbs.
2. Use SDPWS Table 4.4.1 to determine the appropriate ASD uplift capacity for the specified shear
wall nailing of 8d common 6" panel edge spacing, 12" field spacing as follows:
• For 2 rows of nails at top and bottom of panel edges spaced at 4":
o ASD Uplift Capacity = 432 lbs (864 lbs/2) < 440 lbs (19.2" outlooker overhang span) NG
• For 2 rows of nails at top and bottom of panel edges spaced at 3":
o ASD Uplift Capacity = 648 lbs (1,296 lbs/2) > 574 lbs (24" outlooker overhang span) OK
• Therefore 2 rows of 8d common nails spaced at 3" at top and bottom panel edges can be used
for both a 19.2" or a 24" outlooker overhang span.
See Figure 3.2f (shown below and right) for appropriate panel edge
nail spacing (3.2.3.5).
See Special Connections for connections around openings (3.2.3.4).
**WFCM 3.2.3.7a requires that nail spacing not be less than 6"
o.c. for a double row of fasteners to avoid tension perpendicular
to grain stresses in common framing members such as band
joists. An alternative to splicing panels at the band joist is to
splice panels at mid-stud height. Detailing shall be in accordance
with WFCM 3.2.3.7b.
42
WOOD FRAME CONSTRUCTION MANUAL
Table 3.4B
Shear Walls Resisting Uplift and Shear1
(Prescriptive Alternative to Table 3.4)
179
WFCM
Exposure B
2
3
Where framing has a specific gravity of 0.49 or greater, tabulated maximum roof spans shall be permitted to be multiplied by 1.08,
but in no case shall they exceed a span of 36 ft.
Tabulated values for plywood assume plywood with a species of plies having a specific gravity of 0.49 or greater. For plywood with
other species, multiply the tabulated maximum roof spans by 0.90.
4
Wood structural panels shall overlap the top member of the double top plate and bottom plate by 1½" and a single row of fasteners
shall be placed ¾" from the panel edge.
5
Wood structural panels shall overlap the top member of the double top plate and bottom plate by 1½". Rows of fasteners shall be ½"
apart with a minimum edge distance of ½". Each row shall have nails at the specified spacing.
Copyright © American Wood Council. Downloaded/printed pursuant to License Agreement. No reproduction or transfer authorized.
AMERICAN WOOD COUNCIL
43
3
PRESCRIPTIVE DESIGN
Wind Speed 3-second gust (mph)
90
95 100 105 110 115 120 130 140 150 160 170 180 195
(See Figure 1.1)
Top & Bottom of
Wood Structural Panel Shear Wall
Panel Nailing
Requirements
Requirements
2, 3
Maximum Roof Span (ft)
Nail
Sheathing
Shear Wall
Rows of
Spacing
Thickness
Nailing
Nails
(in)
7/16" OSB or
8d Common
4
4
1
15/32" plywood Nails @ 4" panel
36
36
36
36
36
32
24
12
3
with species of edge spacing and
6
36
36
36
36
36
32
24
12
4
36
36
36
36
36
36
36
36
36
32
28
20
16
12
12" field edge
plies having
25
3
36
36
36
36
36
36
36
36
36
36
36
36
32
24
G≥0.49
spacing
6
7/16" OSB or
8d Common
4
36
36
36
36
36
32
24
12
4
1
15/32" plywood Nails @ 6" panel
36
36
36
36
36
36
36
36
28
20
16
12
3
with species of edge spacing and
6
36
36
36
36
36
36
36
36
28
20
16
12
12" field edge
plies having
4
36
36
36
36
36
36
36
36
36
36
36
32
24
20
25
spacing
G≥0.49
3
36
36
36
36
36
36
36
36
36
36
36
36
36
32
6
10d Common
15/32" OSB or
36
36
36
36
36
36
28
20
12
4
14
Nails @ 6" panel
plywood with
36
36
36
36
36
36
36
36
36
24
20
16
12
3
edge spacing and
species of plies
6
36
36
36
36
36
36
36
36
36
24
20
16
12
12" field edge
4
36
36
36
36
36
36
36
36
36
36
36
36
32
24
25
having G≥0.49
spacing
3
36
36
36
36
36
36
36
36
36
36
36
36
36
36
1
See AWC/ANSI Special Design Provisions for Wind and Seismic (SDPWS) for proper design and detailing of wood structural panels
used to resist combined shear and uplift from wind.
SPECIAL DESIGN PROVISIONS FOR WIND AND SEISMIC
Table 4.4.1
43
SDPWS
Nominal Uplift Capacity of 7/16" (Nominal) Minimum Wood Structural Panel
Sheathing or Siding When Used for Both Shear Walls and Wind Uplift Simultaneously
over Framing with a Specific Gravity of 0.42 or Greater 1
Nail Spacing Required for Shear Wall Design
8d Common Nail
8d Common Nail
10d Common Nail
6" panel edge spacing
4" panel edge spacing
6" panel edge spacing
12" field spacing
12" field spacing
12" field spacing
Alternate Nail Spacing at Top and Bottom Plate Edges
3"
6"
4"
3"
6"
4"
3"
6"
4"
3"
Uplift Capacity (plf) of Wood Structural Panel Sheathing or Siding 2,3
6d Common Nail
6" panel edge spacing
12" field spacing
4"
0
168
336
0
216
432
NA
0
216
0
262
524
336
672
1008
432
864
1296
216
648
1080
524
1048
1572
4
1. Nominal unit uplift capacities shall be adjusted in accordance with 4.4.1 to determine ASD allowable unit uplift capacity and LRFD factored unit resistance.
Anchors shall be installed in accordance with this section. See Appendix A for common nail dimensions.
2. Where framing has a specific gravity of 0.49 or greater, uplift values in table 4.4.1 shall be permitted to be multiplied by 1.08.
3. Where nail size is 6d common or 8d common, the tabulated uplift values are applicable to 7/16" (nominal) minimum OSB panels or 15/32" (nominal) minimum plywood with species of plies having a specific gravity of 0.49 or greater. Where nail size is 10d common, the tabulated uplift values are applicable to
15/32" (nominal) minimum OSB or plywood with a species of plies having a specific gravity of 0.49 or greater. For plywood with other species, multiply the
tabulated uplift values by 0.90.
4. Wood structural panels shall overlap the top member of the double top plate and bottom plate by 1-1/2" and a single row of fasteners shall be placed ¾" from
the panel edge.
5. Wood structural panels shall overlap the top member of the double top plate and bottom plate by 1-1/2". Rows of fasteners shall be ½" apart with a minimum
edge distance of ½". Each row shall have nails at the specified spacing.
Table 4.4.1.6
Nail
Size
8d
common
(0.131" x
2-1/2")
10d
common
(0.148" x
3")
Maximum Anchor Bolt Spacing (inches) for Combined Shear and Wind Uplift1,2
Nominal Unit
Shear Capacity
(plf)
G=0.50
0
400
670
980
0
400
870
G=0.42
0
368
616
902
0
368
800
Nominal Uplift Capacity (plf)
0
0
483
48
36
24
483
48
24
216
200
42
42
32
24
42
42
24
432
400
36
36
24
19.2
36
36
24
648
600
36
36
24
19.2
36
36
19.2
864
800
32
32
24
19.2
32
32
19.2
1080
1000
24
24
24
16
24
24
19.2
1296
1200
24
24
19.2
16
24
24
16
1458
1350
19.2
19.2
19.2
19.2
19.2
16
1728
1600
16
16
16
1944
1800
2160
2000
-
-
-
-
-
-
-
-
-
16
16
16
16
-
-
-
-
-
G = Specific Gravity of framing members
Not Permitted
1. The minimum nominal panel thickness of wall sheathing shall be in accordance with Section 4.4.1.2.
2. Tabulated anchor bolt spacings are for minimum ½" diameter “full-body diameter” bolts (see NDS Appendix Table L1)
3. This anchor bolt spacing is provided for interpolation purposes.
Copyright © American Wood Council. Downloaded/printed pursuant to License Agreement. No reproduction or transfer authorized.
AMERICAN WOOD COUNCIL
44
LATERAL FORCE-RESISTING SYSTEMS
NailsSingle
Row 4
NailsDouble
Row 5
6"
WFCM WB
Wall Detailing Summary
Table W5.15 Wall Detailing Requirements for Seismic Loads
Wall
2-2
2-1
2-B
2-A
Stud Size
2x4
2x4
2x4
2x4
Stud Spacing
16"
16"
16"
16"
Interior Sheathing Type
Gyp
Gyp
Gyp
Gyp
Thickness
1/2"
1/2"
1/2"
1/2"
Nail Type
5d cooler
5d cooler
5d cooler
5d cooler
Edge/Field Nailing
7"/10"
7"/10"
7"/10"
7"/10"
Exterior Sheathing Type
WSP
WSP
WSP
WSP
Thickness
15/32"
15/32"
15/32"
15/32"
Nail Type
8d comm.
8d comm.
8d comm.
8d comm.
Edge/Field Nailing
12"
12"
12"
12"
Shear Wall Type
SSW PSW SSW PSW SSW PSW SSW PSW
Edge Nailing
6"
6"
6"
6"
6"
6"
6"
6"
Segment Length
11.5' Full 11.5' Full 11.5' Full 11.5'
Full
Hold-downs, lbs
2151 2151 2151 2151 2151 2151 2151 2151
Shear nailing (per foot)
2-16d
2-16d
2-16d
2-16d
Table W5.16 Wall Detailing Requirements for Wind Loads
Wall
2-2
2-1
2-B
No. 3/Stud
Stud Grade and Size
No. 3/Stud 2x6
No. 3/Stud 2x6
2x6
Stud Length
9'
9'
9'
Stud Spacing
16"
16"
16"
Interior Sheathing Type
Gyp (blocked)* Gyp (blocked)* Gyp (blocked)*
Thickness
1/2"
1/2"
1/2"
Nail Type
5d cooler
5d cooler
5d cooler
Edge/Field Nailing
7"/10"
7"/10"
7"/10"
Exterior Sheathing Type
WSP
WSP
WSP
Thickness
15/32"
15/32"
15/32"
Nail Type
8d comm.
8d comm.
8d comm.
Field Nailing
12"
12"
12"
Shear Wall Type
SSW
PSW
SSW PSW SSW
PSW
Edge Nailing**
4"
4"
4"
4"
3"
3"
No. 8d comm. each strap/stud
4
4
4
4
5***
5***
Segment Length
9.5'
Full
9.5'
Full
11.8'
Full
Hold-downs, lbs
3924
3924
3924 3924 3924
3924
Shear nailing (per foot)
2-16d
2-16d
2-16d
2-A
No. 3/Stud 2x6
13'
16"
Gyp (blocked)*
1/2"
5d cooler
7"/10"
WSP
15/32"
8d comm.
12"
SSW
PSW
3"
3"
5***
5***
11.8'
Full
3924
3924
2-16d
* Blocking required for gypsum segments resisting wind loads with aspect ratios greater than 1.5:1.
** Alternatively, 6" edge nailing requires wall-to-wall steel straps on every stud.
*** Six 8d commons required if 19/32" roof sheathing is used.
45
WFCM WB
Wall Detailing Summary
Perforated Shear Wall
3924 lb hold-downs
4/12 nailing
Blocking for Gypsum resisting
wind with aspect ratio > 1.5:1
Segmented Shear Wall
11.5' required (seismic)
3924 lb hold-downs
4/12 nailing
2-2 (North) Elevation
Perforated Shear Wall
3924 lb hold-downs
4/12 nailing
Blocking for Gypsum resisting
wind with aspect ratio > 1.5:1
Segmented Shear Wall
11.5' required (seismic)
3924 lb hold-downs
4/12 nailing
2-1 (South) Elevation
Segmented Shear Wall
11.8' required
3924 lb hold-downs
3/12 nailing
2-B (East) Elevation
Perforated Shear Wall
3924 lb hold-downs
3/12 nailing
Segmented Shear Wall
11.8' required
3924 lb hold-downs
3/12 nailing
2-A (West) Elevation
46
WFCM WB
FIRST STORY
DESIGN
Wall Framing .......................................................54
Wall Sheathing .....................................................58
Floor Framing ......................................................65
Floor Sheathing ....................................................65
Connections ..........................................................66
Wall Detailing Summary .....................................74
47
WFCM WB
Wall Sheathing
Sheathing and Cladding (WFCM 3.4.4.1)
Choose Exterior Wall Sheathing OR Cladding from Tables 3.13A and 3.13B respectively
Three second gust wind speed (700 yr) and Exposure category: ................
160
mph Exp. B
Sheathing Type (wood structural panels, fiberboard, board, hardboard):... WSP
Strength Axis to Support (Parallel or Perpendicular): ................................ Parallel
Stud Spacing: .............................................................................................. 16
in.
Minimum Panel Thickness to resist suction loads: ..................................... 15/32 in.
LFH = 25 ft
1-2 North Elevation
LFH = 22 ft
1-1 South Elevation
LFH = 25 ft
1-B East Elevation
LFH = 29 ft
1-A West Elevation
48
WFCM WB
Wall Sheathing (cont’d)
Exterior Segmented Shear Walls (WFCM 3.4.4.2)
Choose Exterior Segmented Shear Wall Length from Table 3.17A-D
Wall Height: ................................................................................................
Number of Stories Braced (per 3.1.3.1 and table footnotes):......................
9
2
ft
Three second gust wind speed (700 yr) and Exposure category: ................ 160 mph Exp. B
Maximum shear wall aspect ratio for wind (Table 3.17D Footnote 4): ...... 3.5:1
Minimum shear wall segment length (Wall height/aspect ratio) (9 ft/3.5): 2.6 ft
Seismic Design Category: ........................................................................... D1
Maximum shear wall aspect ratio for seismic (Table 3.17D Footnote 4): .. 3.5:1
Minimum shear wall segment length (Wall height/aspect ratio) (9 ft/3.5): 2.6
NOTE: Aspect ratio can be up to 3.5:1 with adjustments
Minimum WSP sheathing thickness (per WFCM 3.4.4.2): ........................ 3/8
NOTE: Minimum WSP thickness for suction controls
Minimum gypsum thickness (per WFCM 3.4.4.2): .................................... 1/2
NOTE: Aspect ratio limit of 1.5:1 unblocked: 2:1 blocked
Maximum stud spacing (per WFCM 3.4.4.2): ........................................... 16
8d common nails
@ 6” OC on
panel perimeter
8d common
nails @ 12” OC
in field
3/8” wood
structural panel
continuous
height over wall
plates
Panel exterior
ft
in.
in.
in.
5d cooler nails
@ 7” OC on
panel perimeter
5d cooler nails
@ 10” OC in
field
1/2” gypsum
wallboard on
interior
Panel interior
exterior
WFCM 3.4.4.2 “Standard” Shear Wall
WFCM Table 3.17D Footnote 4. The aspect ratio is permitted to be increased to a maximum value
of 3.5:1 provided the unit shear capacity and sheathing type adjustment factor are adjusted in
accordance with SDPWS Section 4.3.3.4.1 Exception 1 for wood structural panel shear walls...
2015 SDPWS 4.3.3.4.1 Exception 1. Where nominal shear capacities of all wood
structural panel shear walls with aspect ratios (h/bs) greater than 2:1 are multiplied
by 2bs/h for design, shear distribution to individual full-height wall segments shall
be permitted to be taken as proportional to the shear capacities of individual full
height wall segments used in design.
49
WFCM WB
Wall Sheathing (cont’d)
Exterior Segmented Shear Walls (WFCM 3.4.4.2)
Table W6.3 Calculation of Exterior Segmented Shear Wall Lengths and Nailing Requirements
Building Wall Elevation
1-2
1-1
1-B
Wall Height
9'
9'
9'
Length (L) or Width (W) of Building being Designed
L=40' L=40' W=32'
Actual Length of Full Height Sheathing (LFH)
25'
22'
25'
Effective Length of Full Height Sheathing for Seismic (LFH-Eff)
22'*
18'*
25'
Tabulated Minimum Length Full Height Sheathing for Seismic
18.1'
18.1'
18.1'
Loads per Table 3.17C1 (R + C + 1F)** L/W = 1.25 (Ls)
S Vertical distribution adjustment per Table 3.17C Footnote 2 (Cvd)
0.92
0.92
0.92
e WSP Perimeter Edge Nail Spacing – Seismic
i (WFCM 3.4.4.2 + 3.4.4.2.1) Note: nail spacing for elevation 1-1
6"
4"
6"
s reduced to provide increased unit shear capacity for seismic.
m
1.0
0.68
1.0
i Sheathing Type Adjustment per Table 3.17D (Csw)
Adjustment
for
other
dead
load
case
Table
3.17C
Footnote
4
(C
)**
1.2
1.2
1.2
dl
c
Min. Length Full Ht. Sheathing – Segmented Seismic
20.0'
13.6'
20.0'
LSSW-S = Ls(Cvd) (Csw) (Cdl)
LSSW-S < LFH-Eff
Ok
Ok
Ok
Tabulated Min. Length Full Ht. Sheathing for Wind per Table
20.7'
20.7'
25.9'
3.17A (Lw) (R + C + 1F)
WSP Perimeter Edge Nail Spacing - Wind (WFCM 3.4.4.2)
W Note: nail spacing for elevation 1-B reduced to provide increased
6"
4"
4"
i unit shear capacity for wind.
n .
Wall and Roof Ht. Adjustment (Table 3.17A Footnote 4) (CWRH)
0.91
0.91
0.91
d
Sheathing Type Adjustment per Table 3.17D (Cswa)
1.0
0.74
0.74
Min. Length Full Ht. Sheathing - Segmented Wind
18.8'
13.9'
17.4'
LSSW-W = Lw (CWRH) (Cswa)
LSSW-W < LFH-Eff
*
**
Ok
Ok
1-A
9'
W=32'
29'
29'
18.1
0.92
6"
1.0
1.2
20.0'
Ok
25.9'
6"
0.91
1.0
23.6'
Ok
Ok
Per Table 3.17D Footnote 4, includes a 2bs/h reduction for exceeding 2:1 aspect ratio for seismic. Effective
lengths can be recalculated as follows to minimize the number of hold-downs:
1-1: 2(5) + 2(0.67)(3) = 14 ft > 13.9 thus eliminating two 3 ft segments and related hold-downs
1-2: 16 + 2(0.67)(3) = 20 ft > 20 ft thus eliminating one 3 ft segment and related hold-downs.
See Table W5.5 footnotes for explanation.
50
WOOD FRAME CONSTRUCTION MANUAL
Table 3.17A
221
WFCM
Exposure B
Segmented Shear Wall Sheathing Requirements for
Wind
Wind Speed
3-second gust (mph)
(See Figure 1.1)
Shear Wall Line Beneath
Roof & Ceiling
Roof, Ceiling, & 2 Floors
Building
Dimension,
L or W (ft)
95
100
105
110
115
120
130
140
150
160
170
180
195
Minimum Length of Full Height Sheathing on Exterior Shear Walls Perpendicular to Building Dimension, L or
W (ft)1,2,3,4,5
12
1.3
1.4
1.5
1.7
1.8
2.0
2.2
2.5
2.9
3.4
3.8
4.3
4.9
5.7
16
1.8
1.8
2.0
2.2
2.4
2.6
2.9
3.4
3.9
4.5
5.1
5.8
6.5
7.6
20
2.2
2.3
2.5
2.8
3.0
3.3
3.6
4.2
4.9
5.6
6.4
7.2
8.1
9.5
24
2.6
2.7
3.0
3.3
3.6
4.0
4.3
5.1
5.9
6.8
7.7
8.7
9.7
11.4
28
3.1
3.2
3.5
3.9
4.2
4.6
5.0
5.9
6.9
7.9
9.0
10.1
11.4
13.3
32
3.5
3.6
4.0
4.4
4.8
5.3
5.8
6.8
7.8
9.0
10.3
11.6
13.0
15.2
36
4.0
4.1
4.5
5.0
5.5
6.0
6.5
7.6
8.8
10.1
11.5
13.0
14.6
17.1
40
4.4
4.5
5.0
5.5
6.1
6.6
7.2
8.5
9.8
11.3
12.8
14.5
16.2
19.0
50
5.5
5.6
6.3
6.9
7.6
8.3
9.0
10.6
12.3
14.1
16.0
18.1
20.3
23.8
60
6.6
6.8
7.5
8.3
9.1
9.9
10.8
12.7
14.7
16.9
19.2
21.7
24.3
28.6
70
7.7
7.9
8.8
9.7
10.6
11.6
12.6
14.8
17.2
19.7
22.4
25.3
28.4
33.3
80
8.8
9.0
10.0
11.0
12.1
13.2
14.4
16.9
19.6
22.5
25.6
28.9
32.4
38.1
20
4.6
4.7
5.1
5.6
6.1
6.7
7.3
8.6
9.9
11.4
13.0
14.6
16.4
19.3
24
5.6
5.6
6.1
6.7
7.4
8.0
8.8
10.3
11.9
13.7
15.6
17.6
19.7
23.1
28
6.5
6.6
7.1
7.8
8.6
9.4
10.2
12.0
13.9
16.0
18.2
20.5
23.0
27.0
32
7.4
7.5
8.1
8.9
9.8
10.7
11.7
13.7
15.9
18.2
20.7
23.4
26.3
30.8
36
8.3
8.4
9.1
10.1
11.0
12.1
13.1
15.4
17.9
20.5
23.3
26.3
29.5
34.7
38.5
40
9.3
9.4
10.1
11.2
12.3
13.4
14.6
17.1
19.9
22.8
25.9
29.3
32.8
50
11.6
11.7
12.7
14.0
15.3
16.7
18.2
21.4
24.8
28.5
32.4
36.6
41.0
48.1
60
13.9
14.1
15.2
16.8
18.4
20.1
21.9
25.7
29.8
34.2
38.9
43.9
49.2
57.8
70
16.2
16.4
17.7
19.5
21.4
23.4
25.5
30.0
34.7
39.9
45.4
51.2
57.4
67.4
80
18.5
18.8
20.3
22.3
24.5
26.8
29.2
34.2
39.7
45.6
51.9
58.5
65.6
77.0
28
9.9
10.0
10.7
11.8
12.9
14.1
15.4
18.0
20.9
24.0
27.3
30.9
34.6
40.6
32
11.3
11.4
12.2
13.5
14.8
16.1
17.6
20.6
23.9
27.5
31.2
35.3
39.5
46.4
36
12.7
12.8
13.7
15.1
16.6
18.2
19.8
23.2
26.9
30.9
35.1
39.7
44.5
52.2
40
14.1
14.2
15.3
16.8
18.5
20.2
22.0
25.8
29.9
34.3
39.0
44.1
49.4
58.0
50
17.7
17.8
19.1
21.0
23.1
25.2
27.5
32.2
37.4
42.9
48.8
55.1
61.8
72.5
60
21.2
21.4
22.9
25.2
27.7
30.3
32.9
38.7
44.8
51.5
58.6
66.1
74.1
87.0
70
24.7
24.9
26.7
29.4
32.3
35.3
38.4
45.1
52.3
60.1
68.3
77.1
86.5
101.5
80
28.3
28.5
30.5
33.6
36.9
40.3
43.9
51.6
59.8
68.6
78.1
88.2
98.8
116.0
See footnotes 1-5.
Copyright © American Wood Council. Downloaded/printed pursuant to License Agreement. No reproduction or transfer authorized.
AMERICAN WOOD COUNCIL
51
3
PRESCRIPTIVE DESIGN
Roof, Ceiling, & 1 Floor
90
WOOD FRAME CONSTRUCTION MANUAL
WFCM
223
Footnotes to Table 3.17A
4 Tabulated sheathing lengths are based on 10 foot walls and 10 foot top plate‐to‐ridge height. For other configurations, the
value may be multiplied by the adjustment factor below:
Roof Pitch
≤6:12
>6:12
Wall Height
Top Plate to
Ridge Height
(ft)
0' (flat)
5'
10'
5'
10'
15'
20'
Roof Only
8'
10'
Roof + 1 Floor
8'
10'
Roof + 2 Floors
8'
10'
Adjustment Factor
0.35
0.50
0.65
0.63
0.92
1.21
1.49
0.43
0.59
0.74
0.71
1.00
1.29
1.58
0.58
0.66
0.74
0.72
0.87
1.01
1.15
0.72
0.79
0.87
0.86
1.00
1.14
1.29
0.66
0.71
0.76
0.75
0.85
0.95
1.04
0.81
0.86
0.91
0.90
1.00
1.10
NP
NP = not permitted
5 10d box nails or equivalent pneumatic nails with a nail diameter of at least 0.131 inch can be substituted for 8d common nails.
Copyright © American Wood Council. Downloaded/printed pursuant to License Agreement. No reproduction or transfer authorized.
AMERICAN WOOD COUNCIL
52
3
PRESCRIPTIVE DESIGN
1 Tabulated sheathing lengths assume studs are spaced a maximum of 16 inches o.c. or exterior wood structural panels are
applied with the long dimension across the studs, walls are sheathed with 3/8 inch wood structural panels on the exterior
attached with 8d common nails at 6 inches o.c. at panel edges and 12 inches o.c. in the field, and 1/2 inch gypsum wallboard
on the interior attached with 5d cooler nails at 7 inches o.c. at panel edges and 10 inches o.c. as specified in section 3.4.4.2.
For other sheathing materials or sheathing configurations the tabulated lengths shall be multiplied by the appropriate
sheathing type adjustment factor in Table 3.17D.
2 Minimum length of full height sheathing shall not be less than the minimum required to satisfy the maximum shear wall
segment aspect ratio limitation in Table 3.17D.
3 Total roof span shall not exceed 36 feet based on 3.1.3.4a. Building dimensions up to 80 feet are shown in the second column
for use with the inscribed building provisions of 3.1.3.3c.
WOOD FRAME CONSTRUCTION MANUAL
229
WFCM
TABLE
3.17DShear
SHEAR
WALL
ASSEMBLY
ALLOWABLE
UNIT
SHEAR CAPACITIES,
MAXIMUM
Table
3.17D
Wall
Assembly
Allowable
Unit Shear
Capacities,
Maximum Shear
Wall
SHEAR WALL
ASPECT
RATIOS,
AND
SHEATHING
TYPE
Segment
AspectSEGMENT
Ratios, and
Sheathing
Type
Adjustments
(Cont.)
ADJUSTMENTS (Cont.)
Exterior Wall Sheathing
Nails and Spacing
Requirements
Interior Wall Sheathing
Wind
Seismic
Wind
400
285
2:1
5d cooler nails 7" edge spacing
475
285
2:1
10d common nails6" edge spacing
800
570
2:1
451
322
2:1
2
15/32" or Thicker Wood Structural Panels
(Blocked)
7/16" Wood Structural Panels (Blocked),
maximum stud spacing 24" on center
5d cooler nails 7" edge spacing
526
322
2:1
8d common nails 4" edge spacing
902
644
2:1
490
350
2:1
2
7/16" Wood Structural Panels (Blocked)
15/32" Wood Structural Panels (Blocked),
maximum stud spacing 24" on center
5d cooler nails 7" edge spacing
565
350
2:1
8d common nails 4" edge spacing
980
700
2:1
490
350
2:1
2
7/16" Wood Structural Panels (Blocked)
3/8", 7/16", and 15/32" Wood Structural Panels
(Blocked), maximum stud spacing 16" on center
5d cooler nails 7" edge spacing
590
350
2:1
8d common nails 4" edge spacing
980
700
2:1
593
423
2:1
2
3/8", 7/16", and 15/32" Wood Structural
Panels (Blocked)
15/32" Wood Structural Panels (Blocked),
maximum stud spacing 24" on center
5d cooler nails 7" edge spacing
668
423
2:1
10d common nails4" edge spacing
1186
846
2:1
0.84
4
0.92
0.84
4
0.55
0.42
4
0.97
0.74
4
0.83
0.74
4
0.48
0.37
4
0.89
0.68
4
0.77
0.68
4
0.44
0.34
4
0.89
0.68
4
0.74
0.68
4
0.44
0.34
4
0.74
0.57
4
0.65
0.57
4
0.37
0.28
4
2:1
4
2:1
4
2:1
4
2:1
4
2:1
4
2:1
4
2:1
4
2:1
4
2:1
4
2:1
4
2:1
4
2:1
4
2:1
4
2:1
10d common nails 4" Edge spacing
No Sheathing or Non-Rated Sheathing
1/2" Gypsum Wallboard (Unblocked)
1.09
2:1
8d common nails 4" edge spacing
No Sheathing or Non-Rated Sheathing
1/2" Gypsum Wallboard (Unblocked)
4
4
8d common nails 4" edge spacing
No Sheathing or Non-Rated Sheathing
1/2" Gypsum Wallboard (Unblocked)
Seismic
8d common nails 4" edge spacing
No Sheathing or Non-Rated Sheathing
1/2" Gypsum Wallboard (Unblocked)
Wind
10d common nails 6" edge spacing
No Sheathing or Non-Rated Sheathing
1/2" Gypsum Wallboard (Unblocked)
Seismic
Sheathing Type
Adjustment Factor
2
15/32" Wood Structural Panels (Blocked)
See footnotes 1-4.
Copyright © American Wood Council. Downloaded/printed pursuant to License Agreement. No reproduction or transfer authorized.
AMERICAN WOOD COUNCIL
53
3
PRESCRIPTIVE DESIGN
15/32" Wood Structural Panels (Blocked),
maximum stud spacing 24" on center
ASD Unit Shear Maximum Shear
Capacity of Wall
Wall Segment
Assembly (plf)
Aspect Ratio
WFCM WB
Wall Sheathing (cont’d)
Exterior Perforated Shear Walls (WFCM 3.4.4.2)
Using Segmented Shear Wall results from Table W6.3, determine Perforated Shear Wall Lengths using
Table 3.17E
Table W6.4 Calculation of Exterior Perforated Shear Wall Lengths and Nailing Requirements
Building Wall Elevation
1-2
1-1
1-B
1-A
Wall Height
9'
9'
9'
9'
Max. Unrestrained Opening Height
7'-6" 7'-6"
4'-6"
7'-6"
Actual Length of Full Height Sheathing (LFH)
25'
22'
25'
29'
Effective Length of Full Height Sheathing for Seismic (LFH-Eff)
22'*
18'*
25'
29'
S Length of Wall (LWall)
40'
40'
32'
32'
e Min. Length Full Ht. Sheathing - Segmented Seismic (LSSW-S)
20.0' 13.6'
20.0'
20.0'
i Percent Full Height Sheathing (L
50% 34%
63%
63%
SSW-S / LWall)
s
1.43
1.66
1.14
1.29
m Perforated Length Increase Factor from Table 3.17E (CL)
i Min. Length Full Ht. Sheathing - Perforated Seismic
28.6' 22.6'
22.8'
25.8'
c LPSW-S = LSSW-S (CL)
LPSW-S < LFH-Eff
NG** NG**
OK
OK
Length of Wall (LWall)
40'
40'
32'
32'
W Min. Length Full Height Sheathing - Segmented Wind (LSSW-W)
18.8' 13.9'
17.4'
23.6'
i Percent Full Height Sheathing (LSSW-W / LWall)
47% 35%
54%
74%
n Perforated Length Increase Factor from Table 3.17E (CL)
1.47
1.64
1.18
1.19
d Min. Length Full Ht. Sheathing - Perforated Wind
27.6' 22.8'
20.5'
28.1'
(LPSW-W = LSSW-W (CL))
LPSW-W < LFH-Eff
NG** NG**
OK
OK
* Includes a 2bs/h adjustment for exceeding 2:1 aspect ratio for seismic. See Table W5.5 for
explanation.
** See Table W6.5 and W6.6 for modifications to nailing patterns and sheathing lengths to allow the
perforated shear wall method to work.
WFCM
54
WFCM WB
Wall Sheathing (cont’d)
Table W6.6 Calculation of Modified Edge Nailing and Sheathing Length Requirements for Wind
Design of Perforated Shear Walls 1-1, 1-2, and 1-A.
Modified Shear Wall Calculations from Tables W6.3 and W6.4
1-2
1-1
Wall Height
9'
9'
Max. Unrestrained Opening Height
7'-6" 7'-6"
Max. Unrestrained Opening Heights as functions of wall height
5H/6 5H/6
Actual Length of Full Height Sheathing (LFH)
Effective Length of Full Height Sheathing (LFH-Eff)
25'
22'*
22'
18'*
Tabulated Min. Length Full Ht. Sheathing for Wind per Table 3.17A (Lw)
WSP Perimeter Edge Nail Spacing - Wind (WFCM 3.4.4.2)
Note: nail spacing for elevations 1-2, 1-1, and 1-A reduced to provide
increased unit shear capacity for wind.
Wall and Roof Ht. Adjustment (Table 3.17A Footnote 4) (CWRH)
Sheathing Type Adjustment per Table 3.17D (Cswa)
Min. Length Full Ht. Sheathing - Segmented Wind
20.7'
20.7'
3"
3"
0.91
0.60
0.91
0.60
11.3'
11.3'
LSSW-W = Lw (CWRH) (Cswa)
Length of Wall (LWall)
40'
40'
Min. Length Full Height Sheathing - Segmented Wind (LSSW-W)
11.3' 11.3'
Percent Full Height Sheathing (LSSW-W / LWall)
28% 28%
Perforated Length Increase Factor from Table 3.17E (CL)
1.76
1.76
Min. Length Full Ht. Sheathing - Perforated Wind
19.9' 19.9'
LPSW-W = LSSW-W (CL)
LPSW-W < LFH-Eff
OK NG**
* Includes a 2bs/h adjustment for exceeding 2:1 aspect ratio. See Table W5.5 for explanation.
55
230
WFCM
PRESCRIPTIVE DESIGN
Table
3.17D
Wall
Assembly
Allowable
Unit Shear
Capacities,
Maximum Shear
Wall
TABLE
3.17D Shear
SHEAR
WALL
ASSEMBLY
ALLOWABLE
UNIT
SHEAR CAPACITIES,
MAXIMUM
Segment
Aspect
Ratios, and
Sheathing
TypeAND
Adjustments
(Cont.)
SHEAR WALL
SEGMENT
ASPECT
RATIOS,
SHEATHING
TYPE
ADJUSTMENTS (Cont.)
Exterior Wall Sheathing
Nails and Spacing
Requirements
Interior Wall Sheathing
7/16" Wood Structural Panels (Blocked),
maximum stud spacing 24" on center
Wind
Seismic
Wind
580
414
2:1
5d cooler nails 7" edge spacing
655
414
2:1
8d common nails 3" Edge spacing
1160
828
2:1
630
451
2:1
2
7/16" or Thicker Wood Structural Panels
(Blocked)
15/32" Wood Structural Panels (Blocked),
maximum stud spacing 24" on center
5d cooler nails 7" edge spacing
705
451
2:1
8d common nails 3" Edge spacing
1260
902
2:1
630
451
2:1
2
7/16" or Thicker Wood Structural Panels
(Blocked)
3/8", 7/16", and 15/32" Wood Structural Panels
(Blocked), maximum stud spacing 16" on center
5d cooler nails 7" edge spacing
730
451
2:1
8d common nails 3" edge spacing
1260
902
170
2
3/8", 7/16", and 15/32" Wood Structural
Panels (Blocked)
3/8" Wood Structural Panels (Unblocked),
maximum stud spacing 16" on center
5d cooler nails 7" edge spacing
8d common nails 6" Edge spacing
4
0.75
0.58
4
0.67
0.58
4
0.38
0.29
4
0.69
0.53
4
0.62
0.53
4
0.35
0.26
4
0.69
0.53
4
0.60
0.53
4
2:1
4
2:1
4
2:1
4
2:1
4
2:1
4
2:1
4
2:1
4
2:1
2:1
4
2:1
4
0.35
0.26
121
2:1
2:1
2.56
1.98
270
121
2:1
2:1
1.61
1.98
340
242
2:1
2:1
1.28
0.99
8d common nails 6" Edge spacing
No Sheathing or Non-Rated Sheathing
1/2" Gypsum Wallboard (Unblocked)
Seismic
8d common nails 3" edge spacing
No Sheathing or Non-Rated Sheathing
1/2" Gypsum Wallboard (Unblocked)
Wind
8d common nails 3" Edge spacing
No Sheathing or Non-Rated Sheathing
1/2" Gypsum Wallboard (Unblocked)
Seismic
Sheathing Type
Adjustment Factor
8d common nails 3" Edge spacing
No Sheathing or Non-Rated Sheathing
1/2" Gypsum Wallboard (Unblocked)
ASD Unit Shear Maximum Shear
Capacity of Wall
Wall Segment
Assembly (plf)
Aspect Ratio
2
3/8" Wood Structural Panels (Unblocked)
See footnotes 1-4.
Copyright © American Wood Council. Downloaded/printed pursuant to License Agreement. No reproduction or transfer authorized.
AMERICAN WOOD COUNCIL
56
Polling Question
6. Which of the following is false regarding shear walls
designed for wind loads?
a) Maximum aspect ratio is 3.5:1
b) Gypsum capacity is additive with WSP capacity
c) Capacity increases as edge nail spacing decreases
d) Cannot be used for perforated shear walls
57
WFCM WB
Wall Sheathing (cont’d)
Since wall 1-1 does not have enough capacity for wind using the Perforated Shear Wall (PSW) method, it
will be designed per 2015 Special Design Provisions for Wind and Seismic (SDPWS) and 2018 WFCM
Chapter 2 Engineered Design provisions. Another option is to use WFCM Table 3.17D adjustments to
design a 2-sided WSP shear wall.
To calculate the wind shear load on wall 1-1, use WFCM Table 2.5B to determine unit lateral loads for
the roof and floor diaphragms. Roof diaphragm load = 169 plf (interpolated) and floor diaphragm load =
194 plf. The floor diaphragm load can be modified by Table 2.5B footnote 2 for a 9' wall height = 0.91.
Per Table 2.5B Footnote 3, Table 2.1.3.1 can be used to reduce the MWFRS load by 0.97 based on a
mean roof height less than 33'. Per Table 2.5B footnote 5, the shear load on wall 1-1 = 32' [194(0.91) +
169](0.97)/2 = 5,370 lbs. Modified results are as follows:
Table W6.7 Calculation of Sheathing Length Requirements for Wind Design of Wall 1-1 using the
Perforated Shear Wall Method from 2015 SDPWS Section 4.3.3.5.
Modified Perforated Shear Wall Calculations from Table W6.6
1-1
Wall Height
9'
Total length of wall (LWall)
40'
Total area of openings (Ao = 6(7.5)+4(3)(4.5)) (ft2)
99
Aspect ratio adjustment per SDPWS 4.3.4.3 (2bs/h)
0.67
18'
Length of full-height sheathing (Li): 2(5') + 4(0.67)(3') = 18 ft
Sheathing area ratio (r) per SDPWS Equation 4.3-6
0.62
Shear capacity adjustment factor (Co) per SDPWS Equation 4.3-5
0.78
Nominal unit shear capacity (v) per SDPWS Table 4.3A and 4.3C assuming 3"
WSP edge nailing, SPF framing, and blocked gypsum with 7" edge nailing:
755
(0.92)1370/2+250/2 = 755 plf
PSW capacity per SDPWS 4.3.3.5 = (v)(Li)(Co) (lbs)
10,600
Load (lbs)
5,370
Load < Capacity
OK
Table W6.8 Bottom Story Shear Wall Edge Nail Spacing and Wall Length Summary
Building Elevation
1-2
1-1
1-B
1-A
Segmented 6"
20.0'
4"
13.6'
6" 20.0'
6" 20.0'
Seismic
Perforated 3"
16.5'
16.5'
3"
6" 22.8'
6" 25.8'
Wind
Segmented
6"
18.8'
4"
13.9'
4"
17.4'
6"
23.6'
Perforated 3" 19.9' 3"
22'
4" 20.5'
6" 28.0'
See shear wall detailing summary tables at the end of this section for a final
comparison of wind vs. seismic results.
58
WOOD FRAME CONSTRUCTION MANUAL
Table 2.5B
69
WFCM
Lateral Diaphragm Loads from Wind - Parallel to Ridge
(For Calculating In-Plane Shear in Roof and Floor Diaphragm)
w floor
Floor
Di aphrag m
2
ENGINEERED DESIGN
w roof
Roof / Ce iling
Di aphrag m
S he ar Wall
w floor
w floor
L
B
Wind Speed
3-second gust (mph)
(See Figure 1.1)
Roof Pitch
1.5:12 - 3:12
4:12
5:12
6:12
7:12
8:12
9:12
10:12
11:12
12:12
*
Roof Span (ft)
24
36
48
60
24
36
48
60
24
36
48
60
24
36
48
60
24
36
48
60
24
36
48
60
24
36
48
60
24
36
48
60
24
36
48
60
24
36
48
60
90
95
100
65
73
80
88
70
80
90
100
75
88
100
113
80
95
110
125
85
103
120
138
90
110
130
150
95
118
140
163
100
125
150
175
105
133
160
188
110
140
170
200
65
73
80
88
70
80
90
100
75
88
100
113
80
95
110
125
85
103
120
138
90
110
130
150
95
118
140
163
100
125
150
175
105
133
160
188
110
140
170
200
65
73
80
88
70
80
90
100
75
88
100
113
80
95
110
125
85
103
120
138
90
110
130
150
95
118
140
163
100
125
150
175
105
133
160
188
110
140
170
200
110
110
110
105
110
115
120
130
140
150
Unit Lateral Loads for Roof Diaphragm, wroofll, (plf)1,3,4,5
65
65
65
65
76
88
101
73
73
73
73
84
97
111
80
80
80
80
92
107
123
88
88
88
88
101
117
134
70
70
70
70
82
95
109
80
80
80
80
92
107
123
90
90
90
90
104
120
138
100
100
100
100
115
134
153
75
75
75
75
87
101
116
88
88
88
88
101
117
134
100
100
100
100
115
134
153
113
113
113
113
130
150
173
80
80
80
80
93
108
124
95
95
95
95
109
127
146
110
110
110
110
127
147
169
125
125
125
125
144
167
192
85
85
85
85
99
115
132
103
103
103
103
118
137
157
120
120
120
120
138
160
184
138
138
138
138
158
184
211
90
90
90
90
105
122
140
110
110
110
110
127
147
169
130
130
130
130
150
174
199
150
150
150
150
173
200
230
95
95
95
95
111
128
147
118
118
118
118
135
157
180
140
140
140
140
161
187
215
163
163
163
163
187
217
249
100
100
100
100
117
135
155
125
125
125
125
144
167
192
150
150
150
150
173
200
230
175
175
175
175
202
234
268
105
105
105
105
122
142
163
133
133
133
133
153
177
203
160
160
160
160
184
214
245
188
188
188
188
216
250
288
110
110
110
110
128
149
171
140
140
140
140
161
187
215
170
170
170
170
196
227
261
200
200
200
200
230
267
307
Unit Lateral Loads for Floor Diaphragm, wfloorII, (plf)1,2,3,5
110
110
110
110
128
149
171
160
170
180
195
115
126
140
153
124
140
157
174
132
153
174
196
141
166
192
218
150
179
209
240
159
192
227
262
168
205
244
284
177
218
262
305
185
231
279
327
194
244
297
349
130
143
158
172
140
158
177
197
150
172
197
222
159
187
217
246
169
202
236
271
179
217
256
295
189
231
276
320
199
246
295
345
209
261
315
369
219
276
335
394
145
160
177
193
156
177
199
221
168
193
221
248
179
210
243
276
190
226
265
304
201
243
287
331
212
259
309
359
223
276
331
386
235
293
353
414
246
309
375
442
170
188
207
227
184
207
233
259
197
227
259
292
210
246
285
324
223
266
311
356
236
285
337
389
249
305
363
421
262
324
389
454
275
343
415
486
289
363
441
518
194
219
246
289
See Footnotes 1 -5.
2 Tabulated unit lateral loads are based on 10 foot wall heights and a 1 foot floor depth. For other wall heights, H, tabulated values for floor diaphragms shall be permitted to be used when
multiplied by (H+1)/11.
3 Tabulated unit lateral loads are based on MWFRS wind loads and assume a building located in Exposure B with a mean roof height of 33 feet. For buildings located in Exposures B with mean
roof heights less than 33 feet, or in Exposures C and D, tabulated values shall be adjusted in accordance with Section 2.1.3.1.
Copyright © American Wood Council. Downloaded/printed pursuant to License Agreement. No reproduction or transfer authorized.
AMERICAN WOOD COUNCIL
59
SPECIAL DESIGN PROVISIONS FOR WIND AND SEISMIC
4.3.3.4.1 Shear distribution to individual shear
walls in a shear wall line shall provide the same calculated deflection, sw, in each shear wall.
2. Where nominal shear capacities of all
structural fiberboard shear walls with aspect
ratios (h/bs) greater than 1:1 are multiplied by
0.1 + 0.9bs/h for design, shear distribution to
individual full-height wall segments shall be
permitted to be taken as proportional to the
shear capacities of individual full height wall
segments used in design. Where multiplied
by 0.1 + 0.9bs/h, the nominal shear capacities
need not be reduced by the adjustment in
4.3.4.2.
4.3.3.5 Shear Capacity of Perforated Shear Walls:
The nominal shear capacity of a perforated shear wall
shall be taken as the tabulated nominal unit shear capacity multiplied by the sum of the shear wall segment
lengths, Li, and the appropriate shear capacity adjustment factor, Co, from Table 4.3.3.5 or calculated
using the following equation:
 r  L tot
CO  

 3  2r   Li
r
1
Ao
1
h Li
where:
r = sheathing area ratio
(4.3-5)
(4.3-6)
Ltot = total length of a perforated shear wall including the lengths of perforated shear wall
segments and the lengths of segments containing openings, ft
Ao = total area of openings in the perforated
shear wall where individual opening areas
are calculated as the opening width times
the clear opening height, ft2. Where sheathing is not applied to framing above or below
the opening, these areas shall be included
in the total area of openings. Where the
opening height is less than h/3, an opening
height of h/3 shall be used
h = height of the perforated shear wall, ft
ΣLi = sum of perforated shear wall segment
lengths Li , ft. Lengths of perforated shear
wall segments with aspect ratios greater
than 2:1 shall be adjusted in accordance
with 4.3.4.3
4.3.4 Shear Wall Aspect Ratios and
Capacity Adjustments
4.3.4.1 The size and shape of shear walls shall be
limited to the aspect ratios in Table 4.3.4.
4.3.4.2 For wood structural panel shear walls with
aspect ratios (h/bs) greater than 2:1, the nominal shear
capacity shall be multiplied by the Aspect Ratio Factor
(WSP) = 1.25 - 0.125h/bs. For structural fiberboard
shear walls with aspect ratios (h/bs) greater than 1:1,
the nominal shear capacity shall be multiplied by the
Aspect Ratio Factor (fiberboard) = 1.09 - 0.09 h/bs.
4.3.4.3 Aspect Ratio of Perforated Shear Wall
Segments: The aspect ratio limitations of Table 4.3.4
shall apply to perforated shear wall segments within a
perforated shear wall as illustrated in Figure 4C. Portions of walls with aspect ratios exceeding 3.5:1 shall
not be considered in the sum of shear wall segments.
In the design of perforated shear walls, the length of
each perforated shear wall segment with an aspect ratio greater than 2:1 shall be multiplied by 2bs/h for the
purposes of determining Li and Li. The provisions of
Section 4.3.4.2 and the exceptions to Section 4.3.3.4.1
shall not apply to perforated shear wall segments.
Copyright © American Wood Council. Downloaded/printed pursuant to License Agreement. No reproduction or transfer authorized.
AMERICAN WOOD COUNCIL
60
4
LATERAL FORCE-RESISTING SYSTEMS
Exceptions:
1. Where nominal shear capacities of all
wood structural panel shear walls with aspect
ratios (h/bs) greater than 2:1 are multiplied by
2bs/h for design, shear distribution to individual full-height wall segments shall be permitted to be taken as proportional to the shear
capacities of individual full height wall segments used in design. Where multiplied by
2bs/h, the nominal shear capacities need not
be reduced by the adjustment in 4.3.4.2.
27
SDPWS
Table 4.3A Nominal Unit Shear Capacities for Wood-Frame Shear Walls1,3,6,7
Minimun
Minimum
Fastener
Nominal Penetration
Sheathing
Panel
in Framing
Material
Thickness Member or
(in.)
Blocking
(in.)
Wood
Structural
Panels Structural I4,5
Wood
Structural
Panels –
Sheathing4,5
Plywood
Siding
Particleboard
Sheathing (M-S "Exterior
Glue" and
M-2 "Exterior
Glue")
Structural
Fiberboard
Sheathing
5/16
3/82
7/162
15/32
15/32
5/16
3/8
3/82
7/162
15/32
15/32
19/32
5/16
3/8
3/8
3/8
1/2
1/2
5/8
1/2
25/32
A
SEISMIC
vs
(plf)
1-1/4
1-3/8
8d
1-1/2
10d
1-1/4
6d
1-3/8
8d
1-1/2
1-1/4
1-3/8
Panel Edge Fastener Spacing (in.)
Fastener
Type & Size
Nail (common or
galvanized box)
6d
10d
Nail (galvanized casing)
6d
8d
Nail (common or
galvanized box)
6d
8d
10d
Nail (galvanized roofing)
11 ga. galv. roofing nail (0.120"
x 1-1/2" long x 7/16" head)
11 ga. galv. roofing nail (0.120"
x 1-3/4" long x 3/8” head)
B
WIND
Panel Edge Fastener
Spacing (in.)
6
4
3
2
vw
vw
vw
vw
400
460
510
560
680
360
400
440
480
520
620
680
6
Ga
vs
(kips/in.)
(plf)
OSB
PLY
13
19
16
14
22
13
11
17
15
13
22
19
10
14
13
11
16
9.5
8.5
12
11
10
14
13
600
720
790
860
1020
540
600
640
700
760
920
1020
4
Ga
vs
(kips/in.)
(plf)
OSB
PLY
18
24
21
18
29
18
15
25
22
19
30
26
13
17
16
14
20
12
11
15
14
13
17
16
780
920
1010
1100
1330
700
780
820
900
980
1200
1330
3
Ga
vs
(kips/in.)
(plf)
OSB
PLY
23
30
27
24
36
24
20
31
28
25
37
33
16
20
19
17
22
14
13
17
17
15
19
18
1020
1220
1340
1460
1740
900
1020
1060
1170
1280
1540
1740
2
Ga
(kips/in.)
OSB
PLY
35
43
40
37
51
37
32
45
42
39
52
48
22
24
24
23
28
18
17
20
21
20
23
22
(plf)
(plf)
(plf)
(plf)
560
645
715
785
950
505
560
615
670
730
870
950
840
1010
1105
1205
1430
755
840
895
980
1065
1290
1430
1090
1290
1415
1540
1860
980
1090
1150
1260
1370
1680
1860
1430
1710
1875
2045
2435
1260
1430
1485
1640
1790
2155
2435
280
320
13
16
420
480
16
18
550
620
17
20
720
820
21
22
390
450
590
670
770
870
1010
1150
240
260
280
370
400
15
18
18
21
21
360
380
420
550
610
17
20
20
23
23
460
480
540
720
790
19
21
22
24
24
600
630
700
920
1040
22
23
24
25
26
335
365
390
520
560
505
530
590
770
855
645
670
755
1010
1105
840
880
980
1290
1455
340
4.0
460
5.0
520
5.5
475
645
730
340
4.0
460
5.0
520
5.5
475
645
730
4
61
35
SDPWS
1. Nominal unit shear capacities shall be adjusted in accordance with 4.3.3 to determine ASD allowable unit shear capacity and LRFD factored unit resistance. For general construction requirements see 4.3.6. For
specific requirements, see 4.3.7.1 for wood structural panel shear walls, 4.3.7.2 for particleboard shear walls, and 4.3.7.3 for fiberboard shear walls. See Appendix A for common and box nail dimensions.
2. Shears are permitted to be increased to values shown for 15/32 inch (nominal) sheathing with same nailing provided (a) studs are spaced a maximum of 16 inches on center, or (b) panels are applied with long
dimension across studs.
3. For species and grades of framing other than Douglas-Fir-Larch or Southern Pine, reduced nominal unit shear capacities shall be determined by multiplying the tabulated nominal unit shear capacity by the
Specific Gravity Adjustment Factor = [1-(0.5-G)], where G = Specific Gravity of the framing lumber from the NDS (Table 12.3.3A). The Specific Gravity Adjustment Factor shall not be greater than 1.
4. Apparent shear stiffness values Ga, are based on nail slip in framing with moisture content less than or equal to 19% at time of fabrication and panel stiffness values for shear walls constructed with either OSB
or 3-ply plywood panels. When 4-ply or 5-ply plywood panels or composite panels are used, Ga values shall be permitted to be multiplied by 1.2.
5. Where moisture content of the framing is greater than 19% at time of fabrication, Ga values shall be multiplied by 0.5.
6. Where panels are applied on both faces of a shear wall and nail spacing is less than 6" on center on either side, panel joints shall be offset to fall on different framing members as shown below. Alternatively, the
width of the nailed face of framing members shall be 3" nominal or greater at adjoining panel edges and nails at all panel edges shall be staggered.
7. Galvanized nails shall be hot-dipped or tumbled.
SPECIAL DESIGN PROVISIONS FOR WIND AND SEISMIC
LATERAL FORCE-RESISTING SYSTEMS
AMERICAN WOOD COUNCIL
Copyright © American Wood Council. Downloaded/printed pursuant to License Agreement. No reproduction or transfer authorized.
Wood-based Panels4
1
Table 4.3C
Unit Shear
for Wood-Frame
Shear
Walls
Table
4.3CNominal
Nominal
UnitCapacities
Shear Capacities
for
Wood-Frame
Shear Walls1
Sheathing
Material
Material
Thickness
Fastener Type & Size
2
5d cooler (0.086" x 1-5/8" long, 15/64" head) or
wallboard nail (0.086" x 1-5/8" long, 9/32" head) or
0.120" nail x 1-1/2" long, min 3/8" head
1/2"
No. 6 Type S or W drywall screws 1-1/4" long
Gypsum wallboard,
gypsum base for
veneer plaster, or
water-resistant
gypsum backing board
5/8"
6d cooler (0.092" x 1-7/8" long, 1/4" head) or
wallboard nail (0.0915" x 1-7/8" long, 19/64" head) or
0.120" nail x 1-3/4" long, min 3/8" head
No. 6 Type S or W drywall screws 1-1/4" long
Max.
Stud
Spacing
(in.)
7
24
4
(kips/in)
(plf)
150
4.0
150
24
unblocked
220
6.0
220
7
16
unblocked
200
5.5
200
4
16
unblocked
250
6.5
250
7
16
blocked
250
6.5
250
4
16
blocked
300
7.5
300
8/12
16
unblocked
120
3.5
120
4/16
16
blocked
320
8.0
320
4/12
24
blocked
310
8.0
310
8/12
16
blocked
140
4.0
140
6/12
16
blocked
180
5.0
180
7
24
unblocked
230
6.0
230
4
24
unblocked
290
7.5
290
7
16
blocked
290
7.5
290
4
16
blocked
350
8.5
350
8/12
16
unblocked
140
4.0
140
8/12
16
blocked
180
5.0
180
16
blocked
500
11
500
4
16
unblocked
150
4.0
150
4
24
blocked
350
8.5
350
7
16
unblocked
200
5.5
200
16
blocked
400
9.5
400
Base: 9
(Two-Ply)
Face ply--8d cooler (0.113" x 2-3/8" long, 0.281" head) or wallboard nail
(0.113" x 2-3/8" long, 3/8" head) or 0.120" nail x 2-3/8" long, min 3/8" head
Face: 7
1/2" x 4'
vs
B
WIND
vw
unblocked
5/8"
0.120" nail x 1-3/4" long, 7/16" head, diamond-point, galvanized
A
SEISMIC
Ga
(plf)
Base ply--6d cooler (0.092" x 1-7/8" long, 1/4" head) or wallboard nail (0.0915"
x 1-7/8" long, 19/64" head) or 0.120"nail x 1-3/4" long, min 3/8" head
1/2" x 2' x 8'
Gypsum sheathing
board
Max. Fastener
Edge Spacing
(in)3
4/7
5/8" x 4'
6d galvanized cooler (0.092" x 1-7/8" long, 1/4" head) or wallboard nail
(0.0915" x 1-7/8" long, 19/64" head) or 0.120" nail x 1-3/4" long, min 3/8" head
Gypsum lath, plain or
perforated with vertical
joints staggered
3/8” lath and
½” plaster
0.092"x 1-1/8" long, 19/64" head, gypsum wallboard blued nail or 0.120" nail
x1-1/4" long, min 3/8" head
5
16
unblocked
360
9.0
360
Gypsum lath, plain or
perforated
3/8" lath and
1/2" plaster
0.092"x 1-1/8" long, 19/64" head, gypsum wallboard blued nail or 0.120" nail
x1-1/4" long, min 3/8" head
5
16
unblocked
200
5.5
200
Expanded metal or
woven wire lath and
Portland cement
plaster
7/8"
0.120" nail x 1-½” long, 7/16" head
6
16
unblocked
360
9.0
360
SPECIAL DESIGN PROVISIONS FOR WIND AND SEISMIC
4
62
37
SDPWS
1. Nominal unit shear capacities shall be adjusted in accordance with 4.3.3 to determine ASD allowable unit shear capacity and LRFD factored unit resistance. For general construction requirements see 4.3.6. For
specific requirements, see 4.3.7.4.
2. Type S or W drywall screws shall conform to requirements of ASTM C 1002.
3. Where two numbers are given for maximum fastener edge spacing, the first number denotes fastener spacing at the edges and the second number denotes fastener spacing along intermediate framing members.
LATERAL FORCE-RESISTING SYSTEMS
AMERICAN WOOD COUNCIL
Copyright © American Wood Council. Downloaded/printed pursuant to License Agreement. No reproduction or transfer authorized.
Gypsumand
andPortland
Portland Cement
Gypsum
CementPlaster
Plaster
WFCM WB
Connections (cont’d)
Lateral, Shear, and Uplift Connections (WFCM 3.2.1 and 3.2.2)
Wall Assembly to Foundation (WFCM 3.2.1.7 and 3.2.2.3)
Choose Sill Plate to Foundation Connection Requirements for Anchor Bolts Resisting Lateral,
Shear, and Uplift Loads from Table 3.2A for Wind and 3.3A for Seismic
Three second gust wind speed (700 yr) and Exposure category: ................ 160 mph Exp. B
Stories supported by Foundation: ...............................................................
2
Sill plate size (based on Tables W6.1 and W6.2): ...................................... 2x6
Anchor Bolt Diameter: ................................................................................
5/8 in.
Table W6.10 Assuming Crawl Space or Basement, determine maximum Anchor Bolt Spacing.
Building Wall Elevation
1-2
1-1
1-B
1-A
Sill plate line dimension (Lsw)
Building dimension perpendicular to sill plate (Table 3.2A)
S
e
i
s
m
i
c
Tabulated number of anchor bolts to resist seismic shear loads (ss)
(Table 3.3A4) (R+C+2F) (interpolated)
Dead load adjustment per Table 3.3A Footnote 5 (Cdl)
Adjusted number of bolts ssa = (ss)(Cdl)
40'
32'
40'
32'
32'
40'
32'
40'
4
4
4
4
1.14
1.14
1.14
1.14
5
5
5
5
Bolt spacing for seismic shear loads (bolts placed 1' from end of sill)
114" 114"
90"
90"
sss = 12 (Lsw-2) / (#bolts-1)
Tabulated number of bolts to resist shear loads from wind
9
9
12
12
(Table 3.2A)(R+2F)
0.91 0.91
0.91
0.91
W Wall and Roof Height Adjustment (Table 3.2A Footnote 4) (CWRH)
i Minimum number of bolts to resist shear loads = Tabulated x CWRH
9
9
12
12
n Bolt spacing for wind shear loads (bolts placed 1' from end of sill)
57"
57"
32"
32"
d sws = 12 (Lsw-2) / (#bolts-1)
Max. bolt spacing to resist wind uplift loads (swu)
36" 36" 22"** 22"**
(Table 3.2C (end zones) & 3.4C)
Max. anchor bolt spacing (lesser of sws, swu, and sss)
36"
36"
22"
22"
**Calculated from WFCM Table 3.4C based on 16" o.c. outlooker spacing (horizontal projection) and 24"
outlooker overhang span with 2 wall dead loads subtracted (0.6 x 121 plf x 16/12 = 97 lbs) and
bottom/sill plate capacity from WFCM Commentary Table 3.2C. Table 3.4C = 671 lbs – 194 lbs (2 walls)
= 477 lbs. WFCM Commentary Table 3.2C calculations = 22". A 19.2" outlooker overhang span would
result in 26" spacing.
See p.29 for Table 3.4C
63
WFCM WB
Connections (cont’d)
Alternatively, use proprietary connectors with the following minimum capacities from Table 3.2,
Table 3.3, and Table 3.4C.
Three second gust wind speed (700 yr) and Exposure category: ................ 160 mph Exp. B
Stories supported by Foundation: ...............................................................
2
Table W6.11 Assuming Crawl Space or Basement, determine required loads for proprietary
connectors.
Building Wall Elevation
1-2
1-1
1-B
1-A
Building dimension W or L
L=40'
L=40'
W=32'
W=32'
R=L/W or W/L for Table 3.3 (see Footnote 1)
1.0
1.0
1.25
1.25
Tabulated
seismic
shear
load
(Table
3.3)
R+C+2F
S
174 plf
174 plf
174 plf
174 plf
e (interpolated)
i
s Adjustment for other dead load case Footnote 3 (Cdl)
1.14
1.14
1.14
1.14
m
i Adjusted seismic shear load = tabulated seismic shear
198 plf
198plf
198plf
198plf
c load (Cdl)
Number of stories receiving lateral wind load
2
2
2
2
(Table 3.2)
Outlooker Spacing
n/a
n/a
16"
16"
Wind uplift (Table 3.4C)
n/a
n/a
671 lbs
671 lbs
W Wall Dead Load Reduction
n/a
n/a
194 lbs
194 lbs
i Adjusted Wind uplift (Table 3.4C)
n/a
n/a
477 lbs* 477 lbs*
n Wind uplift (Table 3.2(U))
218 plf
218 plf
d Wind lateral load (Table 3.2(L))
**
**
**
**
R=L/W or W/L for Table 3.2 (see Footnote)
0.8
0.8
1.25
1.25
Tabulated Wind shear load (Table 3.2(S)) 427R
342 plf
342 plf
534 plf
534 plf
Footnote 3: Sheathing Type Adjustment per Table
0.60
0.60
0.74
1.0
3.17D (Cswa) – assuming PSW
Footnote 4: Wall and Roof Height Adjustment (CWRH)
0.91
0.91
0.91
0.91
Adjusted shear load = Tabulated (CWRH) / (Cswa)
519 plf
519 plf
657 plf
486 plf
* Assumes 24" outlooker overhang span. See Table W6.10 footnote for calculation basis. A 19.2"
outlooker would result in 343 lbs of uplift.
**Table 3.2 Footnote: Determine anchorage for Lateral Loads in foundation design per Section 1.1.4
(might include soil loads).
See p.29 for Table 3.4C
64
WFCM WB
Connections (cont’d)
Uplift Connections (WFCM 3.2.2)
Wall Assembly to Foundation (WFCM 3.2.2.3)
Table W6.12 Wall to Foundation Uplift Strap Connection from Table A-3.4
1-2
Building Wall Elevation
Three second gust wind speed (700 yr) and Exposure category:
1-1
160 mph Exp. B
Framing Spacing
W
i Roof Span
n Tabulated number of 8d Common Nails required in each end of
d 1-1/4" x 20 gage strap every stud
No Ceiling Assembly nail increase (Footnote 3)
Required number of 8d Common Nails in each end of strap every
stud = Tabulated number of nails - Reductions + Increases
*Non-loadbearing wall assemblies in accordance with Table W6.13 (3.2.6.3)
16 in.
32 ft
4
0
4*
Table W6.13 Alternative proprietary connectors with the following minimum capacities
1-2
1-1
1-B
1-A
Building Wall Elevation
Loadbearing Walls - Tabulated minimum uplift connection capacity
n/a
479 lbs
(Table 3.4)
Interior framing adjustment (Footnote 1)
n/a
1.0
Roof
dead
load
reduction
(Table
3.4,
Footnote
2)
=
0
since
the
attic
W
n/a
0 lbs
i floor does not cover the entire second floor
n Wall-to-Wall and Wall-to-Foundation reduction
-194 lbs
-194 lbs
d (Table 3.4, Footnote 3) = [73 plf x 2 walls (16" / 12"/ ft) = 194 lbs]
Non-Loadbearing Walls - Tabulated minimum uplift connection
n/a
671 lbs
capacity (Table 3.4C)
Required minimum capacity of proprietary connector
285 lbs
477 lbs*
= Tabulated minimum capacity with Adjustments
* Assumes 24" outlooker overhang span. See Table W6.10 footnote for calculation basis. A 19.2"
outlooker would result in 343 lbs of uplift.
65
WFCM WB
Connections (cont’d)
Uplift Connections (WFCM 3.2.3)
Wall Assembly to Foundation (WFCM 3.2.2.2 and 3.2.3)
Table W6.14 Alternative to metal straps on every stud - wood structural panels to resist wall plate
to wall stud uplift and shear from Table 3.4B
Building Wall Elevation
1-2
1-1
1-B
1-A
Three sec. gust wind speed (700 yr) and exp. category
160 mph Exp. B
160 mph Exp. B
Roof Span
32 ft
n/a**
W Shear Wall Sheathing Thickness (see p.58)
15/32 in. 15/32 in. 15/32 in. 15/32 in.
i Shear Wall Type and Nailing: size and spacing (panel 8d comm. 8d comm. 8d comm. 8d comm.
n edges and field) (see Table W6.8) - SSW
@ 6"/12" @ 4"/12" @4"/12" @ 6"/12"
d Number of Rows Required - SSW
2
2
2
2
Top & Bottom of Panel Nail spacing - SSW
4"
3"
3"
3"
Shear Wall Type and Nailing: size and spacing (panel 8d comm. 8d comm. 8d comm. 8d comm.
edges and field) (see Table W6.8) - PSW
@ 3"/12" @ 3"/12" @4"/12" @ 6"/12"
Number of Rows Required - PSW
n/a
n/a
2
2
1
1
Top & Bottom of Panel Nail spacing - PSW
NP
NP
3"
3"
1. WFCM Table 3.4B and SDPWS Table 4.4.1 are limited to no less than 4" panel edge spacing for
shear. Wall 1-1 require metal straps on every stud to resist uplift loads or use Segmented Shear Wall
nailing requirements.
** An engineered approach using 2015 SDPWS to design gable end wall (1-A & 1-B) WSPs to resist
combined uplift and shear is as follows:
1. Table W6.13 shows 343 lbs and 477 lbs for 19.2" and 24" outlooker overhang spans, respectively.
2. Use SDPWS Table 4.4.1 to determine the appropriate ASD uplift capacity for the specified shear wall
nailing of 8d common 6" panel edge spacing, 12" field spacing as follows:
• For 2 rows of nails at top and bottom of panel edges spaced at 4":
o ASD Uplift Capacity = 432 lbs (864 lbs/2) < 477 lbs (24"
outlooker overhang span) NG
o ASD Uplift Capacity = 432 lbs (864 lbs/2) > 343 lbs (19.2"
outlooker overhang span) OK
• For 2 rows of nails at top and bottom of panel edges spaced at 3":
o ASD Uplift Capacity = 648 lbs (1,296 lbs/2) > 477 lbs (24"
outlooker overhang span) OK
• Therefore 2 rows of 8d common nails spaced 3" at top and
bottom panel edges can be used for a 24" outlooker overhang
span – 4" for a 19.2" outlooker overhang span.
Additional detailing
• See WFCM Figure 3.2f (shown right) for appropriate panel edge
nail spacing (3.2.3.5).
• See Special Connections for connections around openings
(3.2.3.4).
• Anchor bolts with 3"x3" steel plate washers at 16" o.c. are
required (3.2.3.6).
• Determine sheathing splice requirements over common
horizontal framing members or at mid-stud height (3.2.3.7).
66
WOOD FRAME CONSTRUCTION MANUAL
Table 3.4B
Shear Walls Resisting Uplift and Shear1
(Prescriptive Alternative to Table 3.4)
179
WFCM
Exposure B
2
3
Where framing has a specific gravity of 0.49 or greater, tabulated maximum roof spans shall be permitted to be multiplied by 1.08,
but in no case shall they exceed a span of 36 ft.
Tabulated values for plywood assume plywood with a species of plies having a specific gravity of 0.49 or greater. For plywood with
other species, multiply the tabulated maximum roof spans by 0.90.
4
Wood structural panels shall overlap the top member of the double top plate and bottom plate by 1½" and a single row of fasteners
shall be placed ¾" from the panel edge.
5
Wood structural panels shall overlap the top member of the double top plate and bottom plate by 1½". Rows of fasteners shall be ½"
apart with a minimum edge distance of ½". Each row shall have nails at the specified spacing.
Copyright © American Wood Council. Downloaded/printed pursuant to License Agreement. No reproduction or transfer authorized.
AMERICAN WOOD COUNCIL
67
3
PRESCRIPTIVE DESIGN
Wind Speed 3-second gust (mph)
90
95 100 105 110 115 120 130 140 150 160 170 180 195
(See Figure 1.1)
Top & Bottom of
Wood Structural Panel Shear Wall
Panel Nailing
Requirements
Requirements
2, 3
Maximum Roof Span (ft)
Nail
Sheathing
Shear Wall
Rows of
Spacing
Thickness
Nailing
Nails
(in)
7/16" OSB or
8d Common
4
4
1
15/32" plywood Nails @ 4" panel
36
36
36
36
36
32
24
12
3
with species of edge spacing and
6
36
36
36
36
36
32
24
12
4
36
36
36
36
36
36
36
36
36
32
28
20
16
12
12" field edge
plies having
25
3
36
36
36
36
36
36
36
36
36
36
36
36
32
24
G≥0.49
spacing
6
7/16" OSB or
8d Common
4
36
36
36
36
36
32
24
12
4
1
15/32" plywood Nails @ 6" panel
36
36
36
36
36
36
36
36
28
20
16
12
3
with species of edge spacing and
6
36
36
36
36
36
36
36
36
28
20
16
12
12" field edge
plies having
4
36
36
36
36
36
36
36
36
36
36
36
32
24
20
25
spacing
G≥0.49
3
36
36
36
36
36
36
36
36
36
36
36
36
36
32
6
10d Common
15/32" OSB or
36
36
36
36
36
36
28
20
12
4
14
Nails @ 6" panel
plywood with
36
36
36
36
36
36
36
36
36
24
20
16
12
3
edge spacing and
species of plies
6
36
36
36
36
36
36
36
36
36
24
20
16
12
12" field edge
4
36
36
36
36
36
36
36
36
36
36
36
36
32
24
25
having G≥0.49
spacing
3
36
36
36
36
36
36
36
36
36
36
36
36
36
36
1
See AWC/ANSI Special Design Provisions for Wind and Seismic (SDPWS) for proper design and detailing of wood structural panels
used to resist combined shear and uplift from wind.
WFCM WB
Connections (cont’d)
Overturning Resistance (WFCM 3.2.4)
Hold-downs (WFCM 3.2.4.1)
Table W6.15 Calculate Hold-downs from Table 3.17F for Segmented and Perforated Shear Walls
Building Wall Elevation
1-2
1-1
1-B
1-A
Wall Height
9'
9'
9'
9'
Tabulated hold down connection capacity required –
2151 lbs
2151 lbs
2151 lbs 2151 lbs
seismic (Ts)
WSP Perimeter Edge Nail Spacing – seismic – SSW
6"
1.0
4" 0.68 6" 1.0 6" 1.0
& Hold-down adjustment per Footnote 1 (Cswa)
Adjusted hold-down capacity to account for
increased shear capacity (Tsa-ssw = (Ts) / (Cswa)) –
2151 lbs
3163 lbs
2151 lbs 2151 lbs
seismic - SSW
S Additional story hold-down requirements – seismic 2151 lbs
2151 lbs
2151 lbs 2151 lbs
e SSW (see Table W5.12)
i
Total hold-down requirement for floor to foundation
s
4302 lbs
5314 lbs
4302 lbs 4302 lbs
(Tsa-ssw) – seismic - SSW
m
i WSP Perimeter Edge Nail Spacing – seismic – PSW 3" 0.53 3" 0.53 6" 1.0 6" 1.0
c & Hold-down adjustment per Footnote 1 (Cswa)
Adjusted hold-down capacity (Tsa-psw = (Ts) / (Cswa))
4058 lbs
4058 lbs
2151 lbs 2151 lbs
– seismic - PSW
Additional story hold-down requirements – seismic 2151 lbs
2151 lbs
2151 lbs 2151 lbs
PSW (see Table W5.12)
Total hold-down requirement for floor to foundation
6209 lbs
6209 lbs
4302 lbs 4302 lbs
(Tsa-psw) – seismic - PSW
Tabulated hold-down connection capacity required –
3924 lbs
3924 lbs
3924 lbs 3924 lbs
wind (Tw)
WSP Perimeter Edge Nail Spacing – wind – SSW &
6"
1.0
4" 0.74 4" 0.74 6" 1.0
Hold-down adjustment per Footnote 1 (Cswa)
Adjusted hold-down capacity to account for
increased shear capacity (Twa-ssw = (Tw) / (Cswa)) 3924 lbs
5303 lbs
5303 lbs 3924 lbs
wind
Additional story hold-down requirements – wind –
3924 lbs
3924 lbs
3924 lbs 3924 lbs
W SSW (Table W5.12)
i Total hold-down requirement for floor to foundation
7848 lbs
9227 lbs
9227 lbs 7848 lbs
n – wind – SSW (Twa-ssw)
d
WSP Perimeter Edge Nail Spacing – wind – PSW &
3" 0.60 3" 0.60 4" 0.74 6" 1.0
Hold-down adjustment per Footnote 1 (Cswa)
Adjusted hold-down capacity (Twa-psw = (Tw) / (Cswa))
6540 lbs
6540 lbs
5303 lbs 3924 lbs
- wind
Additional story hold-down requirements – wind –
3924 lbs
3924 lbs
3924 lbs 3924 lbs
PSW (Table W5.12)
Total hold-down requirement for floor to foundation
10464 lbs 10464 lbs 9227 lbs 7848 lbs
– wind – PSW (Twa-psw)
One hold-down can be used on each corner with corner studs connected to transfer shear as shown in
WFCM Figures 3.8a or 3.8b.
68
WOOD FRAME CONSTRUCTION MANUAL
Table 3.17F
233
WFCM
Segmented and Perforated Shear Wall Hold-down Capacity Requirements
Required Hold‐down Connection Capacity (lbs)1,2
Wall Height (ft)
Wind
Seismic
3488
1912
8
9
3924
2151
10
4360
2390
12
5232
2868
14
6104
3346
16
6976
3824
18
7848
4302
20
8720
4780
1 Required hold‐down capacities assume walls are sheathed in accordance with
Section 3.4.4.2. For other wall sheathing types the tabulated hold‐down
capacity shall be divided by the appropriate sheathing type adjustment factor
in Table 3.17D.
2 Hold‐down capacities are tabulated per story. Required hold‐down capacities
shall be summed from the story above to the story below.
3
PRESCRIPTIVE DESIGN
Copyright © American Wood Council. Downloaded/printed pursuant to License Agreement. No reproduction or transfer authorized.
AMERICAN WOOD COUNCIL
69
WFCM WB
Wall Detailing Summary
Table W6.17 Wall Detailing Requirements for Seismic Loads
Wall
1-2
1-1
Stud Grade and Size
2x6 No.3/Stud
2x6 No.3/Stud
Stud Length
9'
9'
Stud Spacing
16"
16"
Interior Sheathing Type
Gyp
Gyp
Thickness
1/2"
1/2"
Nail Type
5d cooler
5d cooler
Edge/Field Nailing
7"/10"
7"/10"
Exterior Sheathing Type
WSP
WSP
Thickness
15/32"
15/32"
Nail Type
8d comm.
8d comm.
Field Nailing
12"
12"
Shear Wall Type
SSW
PSW
SSW
PSW
Edge Nailing
6"
3"
4"
3"
Segment Length
20.0'
Full
13.6'
Full
Hold-downs (2-stories), lbs
4302
6209
6326
6209
Anchor bolt spacing
114"
114"
Shear nailing (per foot)
2-16d
4-16d
4-16d
4-16d
Table W6.18 Wall Detailing Requirements for Wind Loads
Wall
1-2
1-1
Stud Grade and Size
No. 3/Stud 2x6
No. 3/Stud 2x6
Stud Length
9'
9'
Stud Spacing
16"
16"
Interior Sheathing Type
Gyp (blocked)*
Gyp (blocked)*
Thickness
1/2"
1/2"
Nail Type
5d cooler
5d cooler
Edge/Field Nailing
7"/10"
7"/10"
Exterior Sheathing Type
WSP
WSP
Thickness
15/32"
15/32"
Nail Type
8d comm.
8d comm.
Field Nailing
12"
12"
Shear Wall Type
SSW
PSW
SSW
PSW
Edge Nailing**
4"
3"***
3"
3"***
No. Rows Required
2
NP
2
NP
Segment Length
18.8'
Full
13.9'
Full
Hold-downs (2-stories),
7848
10464
9227
10464
lbs
Anchor bolt spacing with
16"****
36"
16"**** 36"
3"x3" steel plate washers
Shear nailing (per foot)
4-16d
4-16d
4-16d
4-16d
*
**
***
1-B
2x6 No.3/Stud
9'
16"
Gyp
1/2"
5d cooler
7"/10"
WSP
15/32"
8d comm.
12"
SSW
PSW
6"
6"
20.0'
Full
4302
4302
90"
2-16d
2-16d
1-A
2x6 No.3/Stud
9'
16"
Gyp
1/2"
5d cooler
7"/10"
WSP
15/32"
8d comm.
12"
SSW
PSW
6"
6"
20.0'
Full
4302
4302
90"
2-16d
2-16d
1-B
No. 3/Stud 2x6
9'
16"
Gyp (blocked)*
1/2"
5d cooler
7"/10"
WSP
15/32"
8d comm.
12"
SSW
PSW
3"
3"
2
2
17.4'
Full
1-A
No. 3/Stud 2x6
9'
16"
Gyp (blocked)*
1/2"
5d cooler
7"/10"
WSP
15/32"
8d comm.
12"
SSW
PSW
3"
3"
2
2
23.6'
Full
9227
7848
9227
16"
4-16d
4-16d
7848
16"
4-16d
4-16d
Blocking required for gypsum segments resisting wind with aspect ratios greater than 1.5:1.
WSP resist combined uplift and shear – no straps.
Using WSP to resist combined uplift and shear not permitted. Either use Segmented Shear Wall details or use
metal straps every stud per Table W6.12.
**** Required for Segmented Shear Wall used to resist combined uplift and shear. For Perforated Shear Wall, use
36" as calculated in Table W6.10.
70
WFCM WB
Wall Detailing Summary (cont’d)
Perforated Shear Wall
10464 lb hold-downs
3/12 nailing
Strap each stud @16"o.c.
Blocking for Gypsum resisting
wind with aspect ratio > 1.5:1
Segmented Shear Wall
18.8' required
Hold-downs as shown
4/12 nailing
3924 lb each
7848 lb
3924 lb 3924 lb
7848 lb
3924 lb each
1-2 North Elevation
Perforated Shear Wall
10464 lb hold-downs
3/12 nailing
Strap each stud @16"o.c.
Segmented Shear Wall
13.9' required
Hold-downs as shown
3/12 nailing
Blocking for Gypsum resisting
wind with aspect ratio > 1.5:1
3924 lb each 3924 lb each 9227 lb
9227 lb
9227 lb
9227 lb
3924 lb each 9227 lb each
1-1 South Elevation
Note that the segmented shear wall detailing summaries show what could be done when summing holddown capacities from upper to lower stories. From a practical standpoint, hold-downs with different
capacities would likely not be used in the same shear wall line. Rather, the maximum hold-down capacity
would typically be specified for all to avoid installation errors. Also note that one hold-down can be used
on each corner of the building with corner studs connected to transfer shear as shown in WFCM Figures
3.8a or 3.8b.
71
WFCM WB
Wall Detailing Summary (cont’d)
Perforated Shear Wall
9227 lb hold-downs
3/12 nailing
Segmented Shear Wall
17.4' required
Hold-downs as shown
3/12 nailing
9227 lb
5303 lb each
5303 lb each
9227 lb
1-B East Elevation
Perforated Shear Wall
7848 lb hold-downs
3/12 nailing
Segmented Shear Wall
23.6' required
Hold-downs as shown
3/12 nailing
7848 lb
7848 lb
3924 lb
3924 lb
1-A West Elevation
Note that the segmented shear wall detailing summaries show what could be done when summing holddown capacities from upper to lower stories. From a practical standpoint, hold-downs with different
capacities would likely not be used in the same shear wall line. Rather, the maximum hold-down capacity
would typically be specified for all to avoid installation errors. Also note that one hold-down can be used
on each corner of the building with corner studs connected to transfer shear as shown in WFCM Figures
3.8a or 3.8b.
72
Polling Question
ϳ͘SDPWS equations for calculating the PSW shear
capacity adjustment factor, Co, assumes which of
the following?
a) Actual area of openings
b) Largest opening height in the PSW
c) Sum of full-height sheathing lengths
d) All of the above
e) a) and c) only
73
This concludes the American Institute of Architects
Continuing Education Systems Course
info@awc.org
www.awc.org
74