2012 irc wall bracing provisions - ohiobbseducation.com 6 bbs2015-462.pdf · a. garage opening...
TRANSCRIPT
Objectives
Upon completion of this module, you will be better able to:
• Discuss continuous sheathing methods include continuous sheathing - Wood Structural Panel, continuous sheathing at garage, continuous sheathing - portal frame.
• Explain method continuous sheathing - structural fiberboard
• Identify end conditions
2012 IRC Wall Bracing 3
Bracing: Panel Material - Continuous
2012 IBC Wall Bracing 4
Continuous Sheathing Bracing Methods:
CS-WSP - Continuously sheathed wood structural panel
CS-G - Continuously sheathed wood structural panel adjacent to garage openings
CS-PF - Continuously sheathed portal frame
CS-SFB - Continuously sheathed structural fiberboard
Table R602.10.4
Bracing: Panel Material - Continuous
Main Concepts – Allows for narrow BWP's
without hold-downs
– BWL's must be fully sheathed with wood structural panel or structural fiberboard sheathing (continuously sheathed)
2012 IBC Wall Bracing 5 R602.10.4.2, Table R602.10.5
Bracing: Panel Material - Continuous
2012 IBC Wall Bracing 6 R602.10.4.2 & R602.10.5
Sheathing Requirements: 1. Sheath full height areas including gable ends 2. Sheath above and below openings 3. Adjacent openings determine minimum BWP length
Too Narrow
Bracing: Panel Material - Continuous
2012 IBC Wall Bracing 7
Method CS-WSP
Continuous Sheathing with Wood Structural Panel • Area above and below openings fully sheathed including gable ends
• Min 3/8" wood structural panel sheathing
Method CS-SFB
Continuous Sheathing with Structural Fiberboard • Area above and below openings fully sheathed including gable ends
• Min 1/2" structural fiberboard sheathing
R602.10.4.2, Table R602.10.4
Bracing: Panel Material - Continuous
2012 IBC Wall Bracing - wind 8
Wall Bracing
Parameter
Continuously Sheathed
Wood Structural Panel
CS-WSP, CS-G, CS-PF
Continuously Sheathed
Structural Fiberboard
CS-SFB
Wind applicability < 110 mph ≤ 100 mph
Seismic applicability A - D2 A - C
Permitted wall heights 8' to 12' 8' to 12'
Corner return length
(both sides of corner)
24" Min.
(or hold downs at first BWP)
32" Min.
(or hold downs at first BWP)
Panel end distance 10' 10'
Table R602.10.4, Figure R602.10.7
Bracing: Panel Material - Continuous
2012 IBC Wall Bracing 9
Table R602.10.5
Method CS-WSP Full-height sheathed wall segments having a length equal or greater than
Table R602.10.5 are counted toward the total bracing length.
Braced wall panel minimum length is based on wall height and height of
the adjacent clear opening.
Too Narrow
a. Garage opening adjacent to method CS-G panel
shall have header. Max opening height includes
header height.
b. Max header height 10 feet, pony wall may be
used above header.
Bracing: Panel Material - Continuous
Method CS-WSP
Method
Adjacent
Clear
Opening
Height (ft.)
Wall Height (ft.)
8 9 10 11 12
CS-WSP
64 24 27 30 33 36
68 26 27 30 33 36
72 27 27 30 33 36
76 30 29 30 33 36
80 32 30 30 33 36
84 35 32 32 33 36
88 38 35 33 33 36
92 43 37 35 35 36
96 48 41 38 36 36
100 44 40 38 38
104 49 43 40 39
108 54 46 43 41
112 50 45 43
116 55 48 45
120 60 52 48
Method
Adjacent
Clear
Opening
Height
(ft.)
Wall Height (ft.)
8 9 10 11 12
CS-WSP
124 56 51
128 61 54
132 66 58
136 62
140 66
144 72
CS-G a 24 27 30 33 36 CS-PF <120 16 18 20 22b 24b
Table R602.10.5 Minimum Length of Braced Wall Panels (in)
Bracing: Panel Material - Continuous
2012 IBC Wall Bracing 11
36'
All panels less than 20′
apart edge to edge
< 20' < 20' < 20'
8'
R602.10.4.2 & Table R602.10.5
Too narrow to be counted
24" 108" 32" 24" 24" 24"
Method CS-WSP
12
Bracing: Panel Material - Continuous
Method CS-G Wood structural panel adjacent to garage opening – Full-height sheathed wall segments to either side of garage openings
– Roof covering dead loads of 3 psf or less (seismic requirement only)
– Applied to one wall line of garage only
– Panel length = bracing length
– 4:1 aspect ratio
12' Max
H/4 R602.10.4, Table R602.10.5
Garage Opening
2012 IBC Wall Bracing
2012 IBC Wall Bracing 13
Bracing: Panel Material - Continuous
4:1 Aspect Ratio (24" min.)
Garage only (roof covering limited to 3 psf in high seismic regions only).
Standard Header
Method CS-G
2012 IBC Wall Bracing 14
Bracing: Panel Material - Continuous
Method CS-PF Continuous portal frame Walls on either or both sides of openings in garage may have wall segment with a maximum 6:1 height-to-length ratio.
Garage Openin
g
H/6
10' max (12' max
with pony wall)
R602.10.6.4 Fully sheathed dwelling
Garage Opening
No hold-downs required OK on raised floor Top of header at 10' max
Top of wall at 12' max Panel length = bracing length
Bracing: Panel Material - Continuous
Extended Header
6:1 Aspect Ratio (16" min.)
Garage only, story above permitted.
R602.10.6.4, Table R602.10.5
Method CS-PF
2012 IBC Wall Bracing 15
Bracing: Panel Material - Continuous
2012 IBC Wall Bracing 17
Methods PFH, PFG and CS-PF
MINIMUM WALL
STUD FRAMING
NOMINAL SIZE
AND GRADE
MAXIMUM
PONY WALL
HEIGHT
(feet)
MAXIMUM
TOTAL
WALL
HEIGHT
(feet)
MAXIMUM
OPENING
WIDTH
(feet)
BASIC WIND SPEED (mph)
85 90 100 85 90 100
Exposure B Exposure C
Tension strap capacity required (lbf)
2 × 4
No. 2 Grade
0 10 18 1000 1000 1000 1000 1000 1000
1 10
9 1000 1000 1000 1000 1000 1275
16 1000 1000 1750 1800 2325 3500
18 1000 1200 2100 2175 2725 DR
2 10
9 1000 1000 1025 1075 1550 2500
16 1525 2025 3125 3200 3900 DR
18 1875 2400 3575 3700 DR DR
2 12
9 1000 1200 2075 2125 2750 4000
16 2600 3200 DR DR DR DR
18 3175 3850 DR DR DR DR
Table R602.10.6.4: Tension Strap Capacity Required for Resisting Wind Pressures Perpendicular to Method PFH, PFG and CS-PF Braced Wall Panels
Bracing: Panel Material - Continuous
2012 IBC Wall Bracing 18
MINIMUM
WALL
STUD
FRAMING
NOMINAL SIZE
AND GRADE
MAXIMUM
PONY
WALL
HEIGHT
(feet)
MAXIMUM
TOTAL
WALL
HEIGHT
(feet)
MAXIMUM
OPENING
WIDTH
(feet)
BASIC WIND SPEED (mph)
85 90 100 85 90 100
Exposure B Exposure C
Tension strap capacity required (lbf)
2 × 4
No. 2 Grade 4 12
9 1775 2350 3500 3550 DR DR
16 4175 DR DR DR DR DR
2 × 6
Stud Grade
2 12
9 1000 1000 1325 1375 1750 2550
16 1650 2050 2925 3000 3550 DR
18 2025 2450 3425 3500 4100 DR
4 12
9 1125 1500 2225 2275 2775 3800
16 2650 3150 DR DR DR DR
18 3125 3675 DR DR DR DR
Table R602.10.6.4 cont.: Tension Strap Capacity Required for Resisting Wind Pressures Perpendicular to Method PFH, PFG and CS-PF Braced Wall Panels
Methods PFH, PFG and CS-PF cont.
Bracing: Panel Material - Continuous
2012 IBC Wall Bracing 20
Method CS-SFB – Continuous Sheathing with Structural Fiberboard • Wall minimum length based on wall height and height of adjacent clear opening
• Maximum wall height = 12′
• Length requirements for braced wall panels in Table R602.10.5
– Same minimum bracing length requirements as CS-WSP
– Same aspect ratio (opening height limits) as CS-WSP
R602.10.5
Bracing: Panel Material - Continuous
2012 IBC Wall Bracing 21
4:1 4:1 6:1 ~2:1
0% to 65% H
0% to 65% H
0% to 65% H
18'
8'
R602.10.5.1
Too narrow to be counted
24" BWP
24" BWP
40" BWP
Method CS-SFB
18'
3:1 6:1 ~2.4:1 6:1
65% to
85% H
65% to
85% H
0% to
65%H 8'
Bracing: Panel Material - Continuous
2012 IBC Wall Bracing 22 R602.10.5.2
32" BWP
40" BWP
Method CS-SFB Too narrow to be counted
Bracing: End Conditions
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End Conditions – 5 separate options WSP return panel and corner panel – 24″ minimum
SFB return panel and corner panel – 32″ minimum
R602.10.7
R602.10.7 End Conditions for Braced Wall Lines with Continuous Sheathing
Bracing: End Conditions
2012 IRC Wall Bracing 24
End Condition 1
Braced wall panel at end of BWL
Return panel on perpendicular wall
R602.10.7
Bracing: End Conditions
2012 IRC Wall Bracing 25
End Condition 2
Braced wall panel at end of BWL
800 lb hold-down in lieu of a return panel fastened to the corner stud
R602.10.7
Bracing: End Conditions
2012 IRC Wall Bracing 26
End Condition 3
Minimum 48″ braced wall panel
No return required
R602.10.7
Bracing: End Conditions
2012 IRC Wall Bracing 27
End Condition 4
Minimum 24 in. or 32 in. corner panel
Minimum 24 in. or 32 in. return panel on perpendicular wall
R602.10.7
Bracing: End Conditions
2012 IRC Wall Bracing 28
End Condition 5 800 lb hold-down in
lieu of a braced wall panel at the end of the BWL,
Hold-down may be fastened to end of the first BWP.
Return panel on perpendicular wall or hold-down
R602.10.7
2012 IBC Wall Bracing 29
Bracing: Panel Material - Continuous
Minimum required CS-WSP = 24"
corner detail CS-SFB = 32"
Figure R602.10.7
18'
9' 84" 84"
32" BWP
32" BWP
24
" o
r 3
2"
Co
rne
r
24
" o
r 3
2"
Co
rne
r
36"
BWP
36"
BWP
Continuous Sheathing Corner Requirements
Bracing: End Conditions
2012 IBC Wall Bracing 30
Gypsum
BWP Material or Infill
16d nail at 12" o.c.
Gypsum
16d nail at 12" o.c.
Table R602.3(1) Item 8
Table R602.3(1) Item 8 - Corner Stud Requirements
BWP Material or Infill
Summary
This module covered: – Continuous sheathing methods: – Continuous sheathing - Wood structural panel – Continuous sheathing at garage – Continuous sheathing - Portal frame
• All use OSB or plywood
• Continuous Sheathing - Structural Fiberboard – Uses structural fiberboard sheathing.
• End conditions for continuous sheathing along braced wall lines. – Required at the end of the braced wall
31 2012 IBC Wall Bracing