Report (2) • AA-577-0lL l�01-?3
1- 77 3 547 �o
CITY OF PORTLAND, OREGON - BUREAU OF DEVELOPMENT SERVICES F
° 1900 SW Fourth Avenue•Portland,Oregon 97201 •503-823-7300+www.portlandoregon.ggy/bds
PRESCRIPTIVE WALL BRACING WORKSHEET
See Residential Wall Bracing Guide for step-by-step instructions on how to use this worksheet
WIND ADJUSTMENT FACTORS
Numbered Lettered'
Table R602.10.1.2(1)assumes wind exposure category B, 30 ft mean roof height,10 ft eave to Wall Lines Wall Lines
ridge height, 10 ft wall height,and 2 braced wall lines sharing load in a given plan direction on a 1st 2nd 3rd 1si 2nd 3rd
given story level. For any other conditions,apply the appropriate adjustment factors. Stork Story Story Story Story Story
EXPOSURE FACTOR -select adjustment factor based on exposure and story height:
(Exposure B is typical. Exposure C only occurs where exposed to open terrain such as shorelines) /
Exposure B - 1 story=1.0 -2 story=1.0 -3 story=1.0
Exposure C -1 story= 1.2 -2 story=1.3 -3 story=1.4
EAVE HEIGHT FACTOR-select support condition&height to determine adjustment factor:
Support Condition Roof Eave To Ridge Height
<5ft <10ft <15ft <20ft
1 Story or Top Story of 2 or 3 Story 0.7 1.0 1.3 1.6
1st Story of 2 Story or 2"d Story of 3 Story 0.85 1.0 1.15 1.3
1St Story of 3 Story 0.9 1.0 1.1 NP
WALL HEIGHT FACTOR-select adjustment factor based on ceiling height: •
r •
- 8 Ft Ceiling = 0.90 -9 Ft Ceiling = 0.95 - 10 Ft Ceiling= 1.0 tl
-11 Ft Ceiling= 1.05 -12 Ft Ceiling= 1.10
NO.OF BRACED 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 �' 2
1 "
TOTAL GENERAL WIND ADJUSTMENT FACTORS
Multiply all of the above adjustment factors for each story: , 1
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. @ Braced Wall Lines
@ Story
GYPSUM WALL BOARD BRACING METHOD-Apply 0.7 adjustment factor if all of the following on itions are met:
-Bracing method is GB and (v, 5
-Gypsum board is attached with 4"spacing at panel edges,including top and bottom plates and p 1J R �
-Blocking is provided at all horizontal joints. Braced Wall Lines °
@ Story
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
@ Story
HOLD DOWN FACTOR-Apply 0.8 adjustment factor if all of the following conditions are met:
-Bracing method is DWB,WSP,SFB,PBS,PCP and HPS methods and
-Limited to I story buildings or top story of 2 or 3 story buildings and
-800#hold down installed at each end of braced wall panels along the braced wall line.
@ Braced Wall Lines
@ Story
CRIPPLE WALL BRACING-Apply 1.15 adjustment factor if cripple walls occur
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 2/13/12 Page 1
CITY OF PORTLAND, OREGON - BUREAU OF DEVELOPMENT SERVICES F
1900 SW Fourth Avenue•Portland,Oregon 97201 •503-823-7300•www.portlandoregon.gov/bds
SEISMIC ADJUSTMENT FACTORS
STORY HEIGHT FACTOR-Select the adjustment factor based on story height All Wall Lines
< 10ft= 1.0 < llft= 1.1 < l2ft= 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 to accommodate 1 single room not exceeding 900 SF.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
@ Story
@ Braced Wall Lines
@ Story
GYPSUM WALL BOARD FACTOR-Apply 1.5 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. @ Braced Wall Lines
@ Story
WALL DEAD LOAD FACTOR-Apply 0.85 adjustment factor if wall dead load is less than or
equal to 8 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 and wall 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 Supporting Roof/Ceiling Dead Load Adj.Factor
Roof Only < 15 psf 1.0
Roof Only >15 psf<25 psf 1.1
Roofplus Occupied Attic > 15 psf<25 psf 1.2
@ Braced Wall Lines
@ Story
CRIPPLE WALL BRACING-Apply 1.15 adjustment factor if cripple walls occur.
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 2/13/12 Page 2
07, CITY OF PORTLAND, OREGON - BUREAU OF DEVELOPMENT SERVICES r-
"',, 1900 SW Fourth Avenue•Portland, Oregon 97201 •503-823-7300•www.portlandoregon.gov/bds
CALCULATIONS FOR LENGTH OF BRACED WALL PANELS STORY
Multiply all adjustment factors and the required wall bracing lengths to determine the total adjusted wall bracing length for each wall line for wind
and for seismic.The bracing length provided shall be equal to or greater than the higher of the two. Provide a separate calculation for each story.
WIND CALCULATION Refer to Table R602.10.1.2(1) ""
Braced Bracing Braced Required General Wind Specific Wind Total Adjusted Bracing Length Bracing
Wall Line Method Wall Line Bracing Adjustment Adjustment (Required Bracing Length Length
Spacing Length Factor Factor(s)* X All Adjustment Factors) Provided
1 '2"
/
2 c ' ®e
3 , ,. , "�° `¢
4
5
A /,
B
. r
C £ ,,14-
D
E
*A braced wall line may have more than one specific 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 Bracing Length Length
Length LengthFactor(s)* X All Adjustment Factors) Provided
1 tiv5e 3c., /A_
2 .," 'r'
3k J
4
5
A
B
,, ,
D
E
*A braced wall line may have more than one seismic adjustment factor. Show all adjustment factors.
All information in this document is subject to change. Prescriptive Wall Bracing Worksheet 2/13/12 Page 3
CALCULATIONS FOR LENGTH OF BRACED WALL PANELS STORY
Multiply all adjustment factors and the required wall bracing lengths to determine the total adjusted wall bracing length for each wall line for wind
and for seismic.The bracing length provided shall be equal to or greater than the higher of the two. Provide a separate calculation for each story.
WIND CALCULATION Refer to Table R602.10.1.2(1)
Braced Bracing Braced Required General Wind Specific Wind Total Adjusted Bracing Length Bracing
Wall Line Method Wall Line Bracing Adjustment Adjustment (Required Bracing Length Length
Spacing Length Factor Factor(s)* X All Adjustment Factors) Provided
l , z- 4'a
2 /7/0 p
•
3 ° ® l w 1 .
4
5
r
A e c-,�.>' ;",r�
B ::>t
J ,,Y,
C •
,tr� alp „.
D
E
*A braced wall line may have more than one specific 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 Bracing Length Length
Length Length ' Factor(s)* X All Adjustment Factors) Provided
1 rf
2 j , //t
3 -+•+
4 .l
5
A .il'� _ ,
D
E
*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 Bracing Worksheet 11/14/11 Page 3
5
5 rZa/z -vary
1 2,7)3 S L 50 ... -.,,
MARK STEWART HOME DESIGN
5/3/2012 PRESCRIPTIVE WALL BRACING WORKSHEET
GERTZ MERLIN MODEL FIRST FLOOR
WIND CALCULATION REFER TO TABLE R602.10.1.2
BRACED WALL LINE BRACING BWL SPACING REQ'D GEN.WIND SPEC.WIND TOTAL ADJUSTED BRACING LENGTH
METHOD BRACING LENGTH ADJUST. ADJUST BRACING LENGTH PROVIDED
REQ'D X ALL ADJUSTMENTS
1 WSP 25.000 10.000 1.235 12.350 <= 20.000
2 GB 35.000 23.750 1.235 0.700 29.331 <= 32.500
3 WSP 35.000 13.625 1.235 16.827 <= 20.000
4
5
A CS 18.000 6.600 1.235 8.151 <= 17.500
B GB 19.000 14.000 1.235 0.700 12.103 <= 20.000
C CS 19.000 7.000 1.235 8.645 <= 37.000
D
• E
SEISMIC CALCULATION REFER TO TABLE R602.10.1.2 (2)
BRACED WALL LINE BRACING BWL LENGTH REQ'D SEISMIC TOTAL ADJUSTED BRACING LENGTH
METHOD BRACING LENGTH ADJUSTMENT BRACING LENGTH PROVIDED
FACTOR(S) REQ'D X ALL ADJUSTMENTS
1 WSP 35.500 16.000 1.100 17.600 <= 20.000
2 GB 36.000 21.600 1.100 23.760 <= 32.500
3 WSP 36.000 16.000 1.100 17.600 <= 20.000
4
5
A CS 32.000 8.080 1.100 8.888 <= 17.500
B GB 32.000 12.600 1.100 13.860 <= 20.000
C CS 32.000 10.710 1.100 11.781 <= 37.000
D
MARK STEWART HOME DESIGN
5/3/2012 PRESCRIPTIVE WALL BRACING WORKSHEET
GERTZ MERLIN MODEL SECOND FLOOR
WIND CALCULATION REFER TO TABLE R602.10.1.2
BRACED WALL LINE BRACING BWL SPACING REQ'D GEN.WIND SPEC.WIND TOTAL ADJUSTED BRACING LENGTH
METHOD BRACING LENGTH ADJUST. ADJUST BRACING LENGTH PROVIDED
REQ'D X ALL ADJUSTMENTS
1 WSP 22.000 4.800 1.170 5.616 <= 12.000
2 GB 20.000 7.750 1.170 0.700 9.068 <= 24.000
3 WSP 20.000 4.500 1.170 5.265 12.000
4
5
A CS 18.000 3.350 1.170 3.920
<= 24.000
•
B GB 18.000 7.250 1.170 0.700 5.938 <= 30.000
C CS 18.000 3.350 1.170 3.920 <= 14.000
' D
E
SEISMIC CALCULATION REFER TO TABLE R602.10.1.2 (2)
BRACED WALL LINE BRACING BWL LENGTH REQ'D SEISMIC TOTAL ADJUSTED BRACING LENGTH
METHOD BRACING LENGTH ADJUSTMENT BRACING LENGTH PROVIDED
FACTOR(S) REQ'D X ALL ADJUSTMENTS
1 WSP 38.000 7.800 1.100 8.580
<= 12.000
2 GB 38.000 11.400 1.100 12.540 <= 24.000
3 WSP 41.500 8.300 1.100 9.130 12.000
4
5
A CS 32.000 5.440 1.100 5.984 <= 24.000
B GB 32.000 9.600 1.100 10.560 <= 30.000
C CS 32.000 5.440 1.100 5.984 <= 16.000
D