Report (3) 0151zotei-o02-39
• 1355 s ui P FA-FFu2 vr
City of Tigard • COMMUNITY DEVELOPMENT DEPARTMENT
11 Residential Wall Bracing Guide RECEIVED
TIGARD 13125 SW Hall Blvd. • Tigard, Oregon 97223 • 503.718.2439 • www.tigard-or.gov
UN 12 2019
BUILDING DIVISION
This step-by-step guide and worksheet is intended to assist designers in applying the prescriptive lateral wall bracing provisions of
the 2011 Oregon Residential Specialty Code,in lieu of a design and calculations by a licensed engineer.The Code must be
consulted while using this guide,and in the case of a conflict between the two,the Code takes precedence.
1. Determine braced wall lines. A braced wall line is an imaginary line which might not occur where actual braced panels are
located. Identify braced wall lines and braced wall panels on a separate schematic floor plan with braced wall lines identified
by numbers in one direction and letters in the opposite direction. Dimension the length of each braced wall line and the distance
between braced wall lines. See Sections R602.10.1.4 and R602.10.1.5.
• Braced wall panels may be offset up to 4 ft from the braced wall line.
• The total out-to-out offset of braced wall panels in a braced wall line may not exceed 8 ft.
• The spacing between braced wall lines may not exceed 25 ft except as noted below.
• In 1 &2 story homes,the bracing may increase to 35 ft to accommodate one room not larger than 900 SF.
2. Determine general adjustment factors for wind. These factors may vary in each direction and for each story.
• Exposure Factor-No adjustment is required for Exposure B,the typical condition in Portland.
See Section R301.2.1.4 in Chapter 3 and Footnote bin Table R602.10.1.2(1).
• Eave Height Factor-No adjustment is required if the eave to ridge height is>5 ft and< 10 ft. See Footnote c in Table
R602.10.1.2(1). If an adjustment is required,the adjustment will vary with each story.
• Wall Height Factor- See Footnote din Table R602.10.1.2(1).
• Number of Braced Wall Lines Factor-See Footnote e in Table R602.10.1.2(1).There is no adjustment if there are
only 2 braced wall lines.
Multiply the above factors together to determine the Total General Wind Adjustment Factor. This must be calculated
for each story and in each direction. Complete top half of Page 1 of the Worksheet.
3. Determine specific adjustment factors for wind. These factors only apply to certain braced wall lines,under certain
conditions,and may or may not apply to any of the braced wall lines. See Worksheet.
• Gypsum Wall Board Factor-If gypsum wall board is not applied to the interior side of an exterior braced wall line,this
factor will occur. See Footnote fin Table R602.10.1.2(1).
• Gypsum Wall Board Bracing Method Factor-If special attachment methods are followed at interior braced wall lines,
the required bracing length can be reduced. See Footnote gin Table R602.10.1.2(1).
• One Sided Gypsum Wall Board Factor-If gypsum board is only attached to one side of an interior braced wall line,
this adjustment factor will apply. See Footnote gin Table R602.10.1.2(1).
• Hold Down Factor-This only applies to one story houses or the top story of multi-story houses. Hold downs must be
installed at each braced panel. See Footnote i in Table R602.10.1.2(1).
• Cripple Wall Bracing Factor-This factor applies if there is a cripple wall.Alternatively,cripple walls may be treated
as an additional story instead of applying this adjustment factor. See Section R602.10.9 and R602.10.9.1.
Calculate each Braced Wall Line separately. Complete the bottom half of Page 1 of the Worksheet.
4. Determine the adjustment factors for seismic. Except for the Story Height Factor,these factors only apply to certain
braced wall lines,under certain conditions.
• Story Height Factor-If the story height is greater than 10 feet, see Table 602.10.1.2(3).
• Braced Wall Line Spacing Factor-If the spacing between braced wall lines is greater than 25 ft,the adjustment factor
increases. See Section 602.10.1.5 &Table 602.10.1.5.
• Wall Dead Load Factor-If the wall dead load is less than or equal to 8 psf,(this is typical for interior walls),the
adjustment factor decreases. See Table 602.10.1.2(3).
• Roof/Ceiling Dead Load Factor-If the roof dead load is large(such as a concrete tile roof)or there is habitable space
in the attic,this adjustment factor is applied. See Table 602.10.1.2(3).
• Cripple Wall Bracing Factor-This factor applies if there is a cripple wall. Alternatively,cripple walls may be treated
as an additional story instead of applying this adjustment factor. See Section R602.10.9 and R602.10.9.1.
• Stone or Masonry Veneer Factor-This factor applies if there is a stone or masonry veneer. See Section 602.12,Table
602.12(2)and Section R703.7 in Chapter 7
Each braced wall line must be calculated separately. Complete Page 2 of the Worksheet.
Alliinrorman on nd't its document is subject teo cn nge. ResVarititChalArlarcialWidge 11/ /i 12012 Page i 1
City of Tigard • COMMUNITY DEVELOPMENT DEPARTMENT
•
11111 : " Residential Wall Bracing Guide
TIGARD 13125 SW Hall Blvd. • Tigard, Oregon 97223 • 503.718.2439 • wwwtigard-or.gov
5. Complete the wind calculation for braced wall length- Refer to top half of Page 3 of the Worksheet.
• Identify bracing method. If Intermittent Sheathing is proposed-the most common options are WSP(Wood Structural
Panel)for exterior walls and GB(Gypsum Board)for interior walls. If Continuous Sheathing is proposed,it is
sufficient to note CS(Continuous Sheathing). See Table R602.10.2 for Intermittent Bracing Methods and Table
R602.10.4.1 for Continuous Sheathing Methods.
• Identify the braced wall line spacing. This is the distance between the braced wall lines,not braced wall panels(see
Step 1.)For interior braced walls the largest dimension must be selected.
• Indicate the Required Bracing Length based on Table R602.10.1.2(1). The Basic Wind Speed for Portland is< 95
mph. Select the appropriate story location. The Required Bracing Length can be interpolated. For example,if the
table requires 2.5 ft of bracing for 10 ft wall line spacing and 5 ft of bracing for 20 ft wall line spacing,the actual
required length of bracing for 15 ft wall line spacing would be 3.75.
• Multiple the Required Bracing Length by the General Wind Adjustment Factor and the Specific Wind Adjustment
Factors and enter the result in Total Adjusted Bracing Length.
6. Complete the seismic calculation for braced wall length -Refer to bottom half of Page 3.
• Identify bracing method. For intermittent sheathing,the most common options are WSP(Wood Structural Panel)for
exterior walls and GB(Gypsum Board)for interior walls. If continuous sheathing is proposed,it is sufficient to note
CS(Continuous Sheathing). For intermittent bracing methods,see Section R602.10.2 and Table R602.10.2 For
continuous sheathing methods,see Section R602.10.4 and Table R602.10.4.1.
• Determine the Braced Wall Line Length-See Figure R602.10.1.3.
• Indicate the Required Bracing Length based on Table R602.10.1.2(2). The Seismic Design Category for Portland is
Dl. Select the appropriate story location. The Required Bracing Length cannot be interpolated.
• Multiple the Required Bracing Length by the Seismic Adjustment Factors to determine the Total Adjusted Bracing
Length.If there are multiple adjustments for one braced wall line,multiply these factors together.
7.Compare the Total Adjusted Bracing Lengths for Wind and for Seismic. Use the greater of the two.
8. Identify Braced Wall Panels on floor plan. Indicate the type of each panel,its location and length.
• For intermittent bracing methods DWB,WSP,SFB,PBS,PCP,HPS,and GB the minimum panel length is 48". See
Section R602.10.3. The effective length of the panel shall be equal to the actual length of the panel. Method ABW is
limited to the 1St story of 1 or 2 story houses and a maximum wall height of 10 ft.and the minimum required length and
hold down varies based on wall height and number of stories. See Section R602.10.3.2,Table R602.10.3.2 and Figure
R602.10.3.2. Method ABW is the equivalent of 48" of braced wall panel. Method PFH is limited to the 1st story of 1
or 2 story houses and a maximum wall height of 10 ft. The minimum required length varies based on wall height and
number of stories. See Section R602.10.3 and Figure R602.10.3.3. Method PFH is the equivalent of 48"of braced
wall panel.
• For all continuous bracing methods the minimum panel length varies,based on wall height and adjacent clear opening
height. See Section 602.10.4.3 and Table 602.10.4.2. Method CS-PF requires a tension strap. See Section
R602.10.4.1.1,Figure 602.10.4.1.1 and Table R602.10.4.1.1.
• A Braced Wall Panel shall be located at each end of the braced wall line and the distance between braced wall panels
shall not exceed 25 feet. The Braced Wall Panel shall be permitted to begin no more than 8 ft from each end of the
braced wall line provided the following occurs:
For the Intermittent braced wall method WSP. Either 1)a minimum 24"wide panel is applied to each side of the
building corner and the two 24"panels at the corner are attached to framing in accordance with Figure R602.10.4.4(1)
or 2)the end of each Braced Wall Panel closest to the corner shall have an 1800 lb hold-down device fastened to the
stud at the edge of the Braced Wall Panel closest to the corner and to the foundation or framing below. See Figure
R602.10.1.4.1.
For the Continuous Sheathing method. Either 1)a minimum 24"wide panel is applied to each side of the building corner
in accordance with Figures R602.10.4.4(1)and R602.10.4.4(5)or 2)the braced wall panel closest to the corner shall have
an 800 lb hold-down device fastened to the stud at the edge of the braced wall panel closest to the corner and to the
foundation or framing below. See Figure R602.10.4.4(5).
All information in this document is subject to change. Residential Wall Bracing Guide Rev. 1/2012 Page 2
City of Tigard • COMMUNITY DEVELOPMENT DEPARTMENT
Prescriptive Wall Bracing Worksheet
T I GARD 13125 SW Hall Blvd. • Tigard, Oregon 97223 • 503.718.2439 • www.tigard-or.gov
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See Residentta �'a :racm Ingeor s ep .y-step ins uc ons on ow o use this wor s eet.
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 10 2nd 3rd
given story level. For any other conditions,apply the appropriate adjustment factors. Story 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) 1.0 1.0 1.0 1.0
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: 1.0 1.3 1.0 1.3
Support Condition Roof E a v e 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 2nd 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: 95 ,95 .95 .95
- 8 Ft Ceiling = 0.90 -9 Ft Ceiling = 0.95 -10 Ft Ceiling= 1.0
- 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: 1.6 1.3 1.6 1.3
-2 Wall Lines: 1.0 - 3 Wall Lines: 1.30 - 4 Wall Lines: 1.45 -5 Wall Lines: 1.60
TOTAL GENERAL WIND ADJUSTMENT FACTORS
Multiply all of the above adjustment factors for each story: 1.52 1.61 1.52 1.61
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 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. .7 @ Braced Wall Lines 3,B
@ Story 1,2
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 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
@ 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
AllliHfurfonaaatidn iinthiadanameintsislljttbgeotdlnacgange. PreiL.. s yatiVallaBtBcaninWrkl het:t 111144/1X2012 Pagd'ige 1
A
City of Tigard • COMMUNITY DEVELOPMENT DEPARTMENT
1111/1• : " Prescriptive Wall Bracing Worksheet
T I GARD 13125 SW Hall Blvd. • Tigard, Oregon 97223 • 503.718.2439 • www.tigard-or.gov
SEISMIC ADJUSTMENT FACTORS
STORY HEIGHT FACTOR-Select the adjustment factor based on story height All Wall Lines
< 10ft= 1.0 < llft= 1.1 < 12ft= 1.2 1.0
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
<25ft = 1.0 < 30 ft = 1.2 <35ft = 1.4
1.0 @ Braced Wall Lines ALL
@ Story ALL
1.0 @ Braced Wall Lines ALL
@ Story ALL
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.)
.85 @ Braced Wall Lines 3,B
@ Story 1,2
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
Roof plus Occupied Attic > 15 psf<25 psf 1.2
1.0/1.1 @ Braced Wall Lines ALL
@ Story 1/2
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 Rev. 1/2012 Page 2
City of Tigard • COMMUNITY DEVELOPMENT DEPARTMENT
III : ;'1 Prescri tive Wall Bracin Worksheet
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��d t e the t I � ,d Il br,c e r aclg�avll line for wind
'.�� a ♦ . I �I ii 2'l,e la 4.1 )1.4:t4 : �s, :.I? '.1 ills' 9 / x � iPP/7:' -'''"-4: l'14p 4.;-11'-' II •
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 l:Atnei IAaiii NS likAttaf lA) r j a AeLtV2C IXi74l saSarateOTANI for eaclp story.
Multiply all adjustment factors and the re'uired allrain len th o determine the total adjusted wall bracing length for each wall line for wind
and for seismic.The bracing length pro f-h PAHA AgkiltANhatiltdelriffleTON1049.2.114civkiDseparate calculation for each story.
Braced Bracing Braced Required General Wind Specific Wind Total Adjusted Bracing Length Bracing
Wall Line Method Wall Lind►7f,7I1SEDICIALC J Illy RiefilisifilEPAle R6O f0!'I4 eflicing Length Length
Braced Bracing €kg Rf€gd Gen iS1cWind SPEitliiiigitid Too Phil tr tciWterfkth %PAW
Wall Line Method Wall Line BracingAdjustment
Adjustment (Required Bracing Length Length t
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habe & a�e �ed batiker Wnd S $ eind TeA lngflth /rgWane Method goyckite IL4{ig Ad mient drt 4 4
P4g l ted
Spacing Length Factor Factor(s)* X All Adjustment Factors) Provided
ICS-SWP 9.25' 3.5' 1.52 5.4' 10.6'
CS-SWP 12.75' 6.5' 1.52 9.9' 17.3'
GB 13.25' 6.5' 1.52 .7 9.9' 36'
CS-SWP 13.25' 6.5' 1.52 9.9' 17.3'
ICS-SWP 8.25' 3.5' 1.52 5.4' 10.7'
ACS-SWP 16.25' 5.5" 1.52 8.4' 27.5'
GB 18.75' 5.5" 1.52 .7 8.4' 25.5'
CS-SWP 18.75' 5.5" 1.52 8.4' 10.5'
A A bced 4all line may have more than one specific wind adjustn+entfactor.
*A braced wall line may have mSEt ite 0pcirjCt1 ,l i n tM Table R602.10.1.2(2)
E
*A braced wall line may have mSAISMiC C,AitiCtibigiirilOriVnitfeielnito Table R602.10.1.2(2)
Braced Bracing Braved Required Seismic Total Adjusted Bracing Length Bracing
Wall Line Method Wall LirISM'CALCULATio eRtefer to Table R tivr, 'ng Length Length
*NTWall Eine Met oo *ja ine �acin OMuslmengt e uire acn LentLenLeng eng ttor,.�s * Xx Q ����iusmenacIfIttigs Provided
Braked Bracing �raEe' Regi�rled F�ett2r 1 Tote'PAflruk eifracingcen th I meg
WalkLine C®y IIP 9:0(9'Line 3,11l'acing 14 justment eequired Bracing Length 1(1)0gth
Length Length F ctor(s), X All Adjustment Factors) P ovided
CS-SWP 12.7 ' 7.7' 1.� 7.7' 11.3'
GB 13.25' 7.7' .85 6.6' 36'
CS-SWP 13.25' 7.7' 1.0 7.7' 17.3'
CS-SWP 8.25' 3.8' 1.0 3.8' 10.7'
i
CS-SWP 16.25' 7.7' 1.0 7.7' 27.5'
X GB 18.75' 7.7' .85 6.6' 25.5'
CS-SWP 18.75' 7.7' 1.0 7.7' 10.5'
*A b ced wall line will be likely to have more than one seismic adjustment factor. Show all adjustment factors.
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City of Tigard • COMMUNITY DEVELOPMENT DEPARTMENT
_' : " Prescri tive Wall Bracin Worksheet
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T I G A P,D U ��> tite ii' d w li '& he t� t St`dd 11 br 'c� g A r PatliRall line for wind
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it.
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 tAtre ts jitaiiiipiN pftittta f l r ag ii lfte21 f l osarate salechtty for eac)1 story.
Multiply all adjustment factors and the reuuiiTredal bra in len th o determine the total adjusted wall bracing length for each wall line for wind
and for seismic.The bracing length prAdddi Oa bl KAKhat iYte 'O erOW•I1Qr 440separate calculation for each story.
Braced Bracing Braced Required General Wind Specific Wind Total Adjusted Bracing Length Bracing
Wall Line Method Wall LintWINEEALCI J KIv Rtilit6'rIble R60401.44 frit cing Length Length
Braced Bracing % €1i18 RidifilikId Gen #S%WUind SWWind TaafilitlAttikMAfitteriffIth Ft5Pd4H1i1
Wall Line Method Wall Line BracingttAdjustment AdjustmentQd TT (Requireda�� Bracing Length Lengthgth
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Spacing Length Factor Factor(s)* X All Adjustment Factors) Provided
1 CS-SWP 22' 8.0' 16.1 12.9' 13.2'
GB 22' 8.0' 1.61 _7 9.1' 36'
CS-SWP 21.5' 8.0' 1.61 12.9' 16.8'
A
A4 CS-SWP 16.25' 5.5" 16.1 8.9' 28.5'
GB 18.75' 5.5" 1.61 .7 6.2' 16.8'
CS-SWP 18.75' 5.5" 1.61 8.9' 14.5'
A A bced n all line may have more than one specific wind adjustment factor.
*A braced wall line may have mgEwsite ovvetfeArtioNnt.f.erevy0 Table R602.10.1.2(2)
E
*A braced wall line may have mSA & IG CAtiCtiLATIONnWeirtrto Table R602.10.1.2(2)
Braced Bracing Braced Required Seismic Total Adjusted Bracing Length Bracing
Wall Line Method Wall Lidd IS11ICALCULAI`�1� eRtefer to Table R l(lfIe1l.pr ng Length h Length
a l DIM as ine raci �EI A��ustmmen { efu re racln n In 4Eeen ttfl
Wla Eine Met o 1Wa g� a rac1 `�"at or s q 1r raclr� Eek Een
V eng#i_};g ,rm jus men ac s Prov, e
Braced Bracing 13190c1 RieWed Ftceta>1i TotXah�djus etc racingen th P�1�aci g
Wal Line CladW4P nail Line 113.6'cing 1Mgljustment 103e(uired Bracing Length 1I: nth
Length Length Factor(s)* X All Adjustment Factors) 569vided
GB 22' 11.5 .94 10.8'
CS-SWP 21.5' 11.5' 1.1 12.7' 16.8'
3
I
4
CS-SWP 16.25' 7.7' 1.1 8.5' 27.5'
GB 18.75' 7.7'
.94 7.3' 25.5'
CS-SWP 18.75' 7.7' 1.1 8.5' 10.5'
*A b ced wall line will be likely to have more than one seismic adjustment factor. Show all adjustment factors.
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*V b4040811 flh il4QilRT}itbsil>9-SI Neone seismic adjust adjustkensicOhM Nil,tintiNSOOsceitors. 11/14/11 Page 3