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A Vin) CITY OF PORTLAND, OREGON BUREAU OF DEVELOPMENT SE ►""' •.
1 SERVICES
,;fes 1900 SW Fourth Avenue•Portland, Oregon 97201 •503-823-7300•www.portlandoregon.gov/bds
ndoregon.gov/bds
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l ,� .. .,,iii►CRIPTIVE WALL BRACING WORKSHEET
See Residential Wall Bracco Guide for step-by-step instructions on how to use this worksheet
SHEE T
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MAR 0 / -WIND ADJUSTMENT FACTORS
TableR�2�y1P °a aaell:sw� dexposure category B, 30 ft mean roofheight, l0 ft eave to Numbered
Lettered
ri dge hea-h[, IQ.�f x. i 'lett ced wall lines sharing load in a given plan direction on a
i ven 0. a w ' Wall Lines Wall Lines
g !j� .a y b hr;r oondations,apply the appropriate adjustment factors. sr
E NPQSURE FACTOR -select adjustment factor based on exposure and story height: Sto Sto Sto Sto Sto 5tp
(Expoare B is typical. Exposure C only occurs where exposed to open terrain such as shorelines)
Exposure B - 1 storystory
— 1111111
-2 sto `'0 1111111) 0
Eacposire C - l story=1.2 -2 story 1.0 3 story=1=1.3 -3story=l.4
EA VE[EIGHT FACTOR-select support condition&height to determine adjustment factor:
Support Condition sof Eave To Ridge Height ,� 111111111/11111111111
I S tory or Top Story of 2 or 3 Story � 0.7_41 1'l <10 ft <20 ft
Is'Sto of Sto ort' Sto of Sto Wan 1.0 1.3 1.6
I"'Storybf3 Story 1 0 1.15 t1.
0.9 1.0 1.1 NP
WALLHEIGHT FACTOR-select adjustment factor based on ceiling height:
- S FSC Ceiling
= 0.90 -12 Ft Ceiling = 0.95 �r --�
I 1 ft Ceilin10 Ft Ceiling= 1.0 -®
g= 1.05 - Ft Ceiling= 1.10
NO. OFBRACED WALL LINES FACTOR
-select adjustment factor based on number of braced wall lines:
- 2 Wall Lines: 1.0 - 3 Wall Lines: 1.30 - 4 Wall Lines: 1.45 -5 Wall Lines: 1.60 ®--1111311111
111
TOTALGENERAL WIND ADJUSTMENT FACTORS
11111111111111/21111111111
Multiply all of the above adjustment factors for each story:
SPECIFIC WIND ADJUSTMENT FACTORS-Specific to certain types of bracing methods or building conditions.
GYPSUM WALL BOARD FACTOR-Apply 1.4 adjustment factor if all the following conditions occur:
-Bracing method is either DWB,WSP,FSB,PBS,PCP or HPS and
-Gypsum board is not applied to inside face of braced wall panels. r
@ Braced Wall Lines
loGYPSUM WALL BOARD BRACING METHOD-Apply 0.7 adjustment factor if all of the following conditions are met:
- Bracing method is GB and
-Gypsum board is attached with 4"spacing at panel edges,including top and bottom plates and
•
-Blocking is provided at all horizontal joints.
@ Braced Wall Lines
@ ONE SIDED GYPSUM WALL BOARD FACTOR - Apply 2.0 adjustment factor if all of the following conditions are met:
-Bracing method is GB and
-Gypsum board is only attached to one side.
@ Braced Wall Lines
HOLD DOWN FACTOR-Apply 0.8 adjustment factor if all of the following conditions are met: @ Story
-Bracing method is DWB,WSP,SFB,PBS, PCP and HPS methods and
- Limited to 1 story buildings or top story of 2 or 3 story buildings and
- 8004 hold down installed at each end of braced wall panels along the braced wall line.
@ Braced Wall Lines
CRIPPLE WALL BRACING -Apply 1.15 adjustment factor if cripple walls occur @Story
Wall panel spacing shall be decreased to 18 ft.See additional requirements in Section 602.10.9.1
@ Braced Wall Lines
All information in this document is subject to change. Prescriptive Wall Bracing Worksheet 1 1/14/1 1 Page 1
3
� �Y° CITY OF PORTLAND, OREGON - BUREAU OF DEVELOPMENT SERVICES r'�.�-.
.a— 1900 SW Fourth Avenue•Portland, Oregon 97201 • 503-823-7300•www.portlandoregon.gov/bds
SEISMIC ADJUSTMENT FACTORS
STOIY HEIGHT FACTOR-Select the adjustment factor based on story height
All Wall Lines
< 10ft=1.0 < 11ft= 1.1 ) 2—
1.2
BRACED WALL LINE SPACING FACTOR- Select the adjustment factor if braced wall line spacing is greater than
25 ft. The spacing can only exceed 25 ft once in each direction. When a braced wall line has a parallel braced wall line on both sides,
the larger adjustment factor shall be used. See additional requirements in Section 602.10.1.5
<25 ft = 1.0 < 30 ft = 1.2 <35 ft = 1.4
@ Braced Wall Lines 344
@ Story
Braced Wall Lines /4-2
WALLDEAD LOAD FACTOR-Apply 0.85 adjustment factor if wall dead load is less than or Story
equal tog psf, (This applies only to interior walls with gypsum board on each side.)
@ Braced Wall Lines
@ Story
ROOF/CEILING DEAD LOAD FACTOR FOR WALL SUPPORTING - Select adjustment factor based on the roof/ceiling dead
load andwall support condition. (Typical composition or metal roof covering will have a roof dead load< 15psf if no ceiling finish is
installed, The addition of a finished ceiling will increase the dead load to> 15 psf.
Wall Su. cortin: Roof/Ceilin: Dead Load Ad'. Factor
Roof Onl
Roof Onl ].0
Roof.lus Occu.ied AtticIEMEgrglIllm
1.2
�! @ Braced Wall Lines iZ
CRIPPLE WALL BRACING-Apply 1.15 adjustment factor if cripple walls occur. @Story
Wall panel spacing shall be decreased to 18 ft. See additional requirements in Section 602.10.9.1
@ Braced Wall Lines `—
@ Story
WALLS WITH STONE OR MASONRY VENEER
See Section 602,12 and 703.7. Braced wall length shall not be less than required by Table 602.12(2)
All information in this document is subject to change. Prescriptive Wall Bracing Worksheet 1 1/14/1 1 Page 2
oY
•t Q CITY OF PORTLAND, OREGON - BUREAU OF DEVELOPMENT SERVICES
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1900 SW Fourth Avenue•Portland,Oregon 97201 .503-623-73pp•wv ,.
portlandoregon.govlbds
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CALCULATIONS FOR LENGTH OF BRACED WALL PANELS STORY
Mu I tiply all adjustment factors and the required wall bracing lengths to determine the total adjusted wall bracing length for each wall line for d
and for seismic.The bracing length provided shall be equal to or greatee than the higher of the two. Provide a separate calculation for each story,
WIND CALCULATION Refer to Table R602.10.1.2(1)
E3 raced Bracing Braced Required General Wind Specific Wind Total Adjusted Bracing Length Bracing
Wall Line Method Wall Line Bracing Adjustment Adjustment
s * (Required Bracing Length Length
Spacing Length Factor Factor
(s) X All Adjustment Factors) Provided
1 k Z'( fo 1,1 z — Z-
2 GS-t.5 " 2-4 I I -1 Z —
C�
3
St A t I '2' , EMI
4 S 4,5 l (o � `-� l z b '24
5
1.111111
A 111111111
B _
C
D
E
*A braced wall line may have more than one speciftc wind adjustment factor.
SEISMIC CALCULATION Refer to Table R602.10.1.2 (2)
Braced Bracing Braced Required Seismic
Total Adjusted Bracing Length Bracing
Wall Line Method Wall Line Bracing Adjustment (Required BracingLength
Length Length Factor(s)* Length
! X All Adjustment Factors) Provided
1 FA 4 I 3, / . -z moi', S" MA
2 AM= } 3
3 S'(JS IIESI -/ - , /
111
5 1111111111111111111 14
111111111
11111111
D
111111111
1111111
*A braced wall line will be likely to have more than one seismic adjustment factor. Show all adjustment factors.
All information in this document is subject to change. Prescriptive Wall BracingWorksheet 1 I/14/I 1
Page 3