WALL SOLUTIONS
SHEAR
BRACE
2006 IBC/IRC
Code Accepted*
*Achieved code evaluation
report recognition
(ICC ES ESR-2652)
for compliance with
the 2006 IBC/IRC
Featuring iLevel® Shear Braces for
Engineered and Prescriptive Applications
■
Engineered for Performance
■
Designed for Safety
■
■
■
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#TJ-8620 SPECIFIER’S GUIDE
www.iLevel.com
1.888.iLevel8 (1.888.453.8358)
Built for Wood Structures
ompatible with IRC Bracing
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Requirements
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erfect for Narrow Wall
P
Sections
uick and Easy Installation
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with Anchor Bolt Kit
Limited Product Warranty
iLEVEL® SHEAR BRACE
WHAT IS AN
iLEVEL SHEAR BRACE?
®
The iLevel® Shear Brace (iSB) is a specially designed, prefabricated,
engineered-wood panel that helps homes resist lateral forces such as those
created by earthquakes and high winds. The International Residential Code
(IRC) and International Building Code (IBC) require wall bracing for lateral
loads in all residential structures. The iLevel® Shear Brace can help you meet
these requirements efficiently and confidently with the following features:
■
Can be used in prescriptive specification or engineered design
■
Narrow panel widths have high allowable loads
■
Tall wall and multistory applications
■
Field adjustable—can be trimmed and drilled
12" braces up to 9' tall and all 18" braces can be substituted, 1-for-1, for any
field-built, prescriptive brace panel
■
Available iLevel® Shear Braces
TABLE OF CONTENTS
iLevel® Shear Brace Descriptions 2–3
Kit Descriptions
4
Engineered Design General
Assumptions
5
Allowable Design Loads—
Standard Brace
6
Allowable Design Loads—
Braces on Raised Floor Kits
7
Portal Frame Assembly
8
Portal Design Information
8
Allowable Design Loads—
Portal Frame
9
Allowable Design Loads—
Stacked Shear Braces
10
Overturning Forces
11
Installation Details, Trim Zones,
and Allowable Holes
12
Raised Floor Details
13
Portal Installation Details
14
Multistory Kit Installation Details 15
Anchorage Embedment Depth
16
Alternate Anchorage for
12" Shear Braces
16
Anchor Bolt Installation
17
Anchorage Details
18–19
Prescriptive Specification
Wall Bracing
20
How to Prescriptively Specify
Braced Panels
20
Prescriptive Bracing
Requirements
21
Prescriptive Brace Example
21
Portals
22
Portal Header Sizing Table
22
Prescriptive Anchorage
23
Alternate Anchorage for
12" Shear Braces
23
2
Brace (1)
Width
Height (2)
iSB 12x7
iSB 12x7.5
iSB 12x8
iSB 12x9
iSB 12x10
iSB 12x11
iSB 12x12
iSB 12xCustom
iSB 18x7
iSB 18x7.5
iSB 18x8
iSB 18x9
iSB 18x10
iSB 18x11
iSB 18x12
iSB 18xCustom
iSB 18xCustom–STK
iSB 24x8
iSB 24x9
iSB 24x10
iSB 24x11
iSB 24x12
iSB 24xCustom
iSB 24xCustom–STK
12"
12"
12"
12"
12"
12"
12"
12"
18"
18"
18"
18"
18"
18"
18"
18"
18"
24"
24"
24"
24"
24"
24"
24"
78"
851/2"
931/4"
1051/4"
1171/4"
1291/4"
1411/4"
78"–1411/4"(3)
78"
851/2"
931/4"
1051/4"
1171/4"
1291/4"
1411/4"
78"–1411/4"(3)
931/4"–1411/4"(4)
931/4"
1051/4"
1171/4"
1291/4"
1411/4"
931/4"–1411/4"(3)
931/4"–1411/4"(4)
Minimum
Trimmed
Height
741/2"
82"
893/4"
78"
78"
78"
78"
78"
741/2"
82"
893/4"
78"
78"
78"
78"
78"
N.A.(4)
893/4"
893/4"
893/4"
893/4"
893/4"
893/4"
N.A.(4)
Kit
Weight Portal
(Included
(lbs) with
Brace)
90
Yes
95
Yes
105
Yes
115
125
140
150
Varies
130
Yes
140
Yes
150
Yes
170
185
205
220
Varies
Varies
200
225
250
270
295
Varies
Varies
Brace Type
Portal
Portal
Portal
Standard(2)
Standard(2)
Standard(2)
Standard(2)
Standard(2)
Portal
Portal
Portal
Standard(2)
Standard(2)
Standard(2)
Standard(2)
Standard(2)
Stacked(5)
Standard
Standard
Standard
Standard
Standard
Standard
Stacked(5)
(1) 12" Brace may only be used in first story applications. 18" and 24" braces may be used in first and second story ­applications.
(2) 12" and 18" braces may be used as a portal brace if trimmed to a height of 78"–931/4".
(3) Custom heights are available in 1⁄8" increments.
(4) Order to the nearest 1⁄8" of the required height. First-story braces in stacked applications may NOT be trimmed. If used in
non-stacked applications, braces may be trimmed; 78" minimum height required for 12" and 18" braces, and 89¾" minimum
height required for 24" braces.
(5) A stackable (STK) brace is required as the bottom brace in a stacked-brace application.
Available Kits (see page 4 for parts list)
■
■
A nchor kits: Required for all braces except braces in second story
applications.
R
aised floor kits (RFK): Required when installing brace on a raised floor
using detail SB8. Not required for SB9. See page 13 for details.
■
Portal kits: Required for brace-to-header connections.
■
Multistory kits (MSK): Required for stacked-brace applications.
Brace Naming System
iSB 18x8-STK
Stackable
Nominal height (ft)
Width (in.)
iLevel® Shear Brace
Code Evaluation: See ICC ES ESR-2652
iLevel® Shear Brace Specifier’s Guide TJ-8620
January 2009
iLEVEL® SHEAR BRACE DESCRIPTIONS
Standard
Shear
Brace
Portal
Shear
Brace
Tall Wall
Shear
Brace
Stackable
Shear
Brace
Standard
Shear
Brace
iSB Standard brace
iLevel® Shear Braces
are trimmable in most
­applications. See page 12
for details.
Easy header
connections
Convenient access
for wiring
Field drillable
and trimmable
■
■
iSB Stackable Brace
iSB Portal Brace
Narrow wall spaces
■
Narrow wall spaces
■
Narrow wall spaces
Top brace in two-story
■
Garages
■
Bottom brace in two-story
■
Large windows and doors
applications
■
Lower brace must
be STK-designated,
stackable brace
Resists bowing,
twisting, and
shrinking
Simple connection
iSB Standard Brace
MSK for stacked
applications,
includes upper
holdowns
Balloon framing
applications
■
Multi-story installation kit
available (order seperately)
iLevel® Shear Brace Specifier’s Guide TJ-8620
January 2009
3
KIT DESCRIPTIONS
Anchor Kits
Required for all braces except braces in second-story applications. Kit includes two jam nuts, two double nut and
washer assemblies, two bolt holders, and one anchor bolt spacer (specify width). Order threaded rod separately.
Anchor Bolt
Spacer Length (1)
121 ⁄8"
18"
24"
Bolt Holder
Diameter
7⁄8"
7⁄8"
1"
Nut Thread
Size
9 UNC
9 UNC
8 UNC
Washer
Type
2" Square/Round
2" Square/Round
2" Round
(1) Flat anchor bolt spacers are available in 121⁄8" and 18" lengths for CMU
and Epoxy Anchor applications.
Anchor Kit Naming
System
Anchor Kit 18
Brace width (in.)
Kit name
Raised Floor Kits (RFK)
Required when installing brace on a raised floor using detail SB8. Kit includes two threaded rods (length precut to
match floor system depth), two steel shims, two ported couplers, one TimberStrand® LSL block with metal plates
top and bottom, and one USP MP4F framing anchor. See page 13 for installation details. For use with 12" and 18"
braces only.
First Floor
Joist Depth
Overall
Width
9 1/2"–16"
Brace width
+ 3"
Available for Available for Available for
12" iSB
18" iSB
24" iSB
Yes
Yes
No
RFK Naming System
Raised Floor Kit 18x91/2
Floor joist
depth (in.)
Brace width (in.)
Kit name
Portal Kits
Required for brace-to-beam connections. Kit includes four iLevel straps and comes standard with portal braces.
Order the kit seperately if using standard braces in a portal application.
Multistory Kits (MSK)
Required for stacked-brace applications. Kit includes two threaded rods (length pre-cut to match floor system
depth), two holdowns with welded-on nuts, two bearing plates, two nuts, nail-gun nails, one T-plate, and three
USP MP4F framing anchors. See page 15 for installation details. For use with 18" and 24" braces only.
Second Floor
Joist Depth
91 ⁄ 2"–16"
Available for
12" iSB
No
Available for
18" iSB
Yes
Available for
24" iSB
Yes
MSK Naming System
MultiStory Kit 18x91/2
Floor joist
depth (in.)
Brace width (in.)
Kit name
4
iLevel® Shear Brace Specifier’s Guide TJ-8620
January 2009
ENGINEERED DESIGN GENERAL ASSUMPTIONS
Design Assumptions for iLevel® Shear Braces
■
■
iLevel® Shear Braces meet the Acceptance Criteria for Prefabricated Wood Shear
Panels (ICC-ES AC 130).
iLevel® Shear Brace design values are consistent with typical wood-framed
construction. Use the following values when designing:
Building Code
1997 UBC
2000 IBC
2003 and 2006 IBC
■
■
■
■
R
5.5
6
6.5
Ω
2.8
3
3
Cd
N.A.
4
4
All table values throughout this bulletin are based on concrete with f'c of
2,500 psi.
Install products according to this specifier's guide. Changes in installation
methods or modification to the product and associated systems (other than those
indicated in this guide) should only be made by a design professional of record.
Altered installation procedures and the performance of modified products are the
sole responsibility of the design professional of record.
The building shall be designed in accordance with the appropriate building code
and meet local, state, and federal requirements. Verify design requirements with
the local building official. Concrete foundation design remains the responsibility
of the design professional of record.
iLevel® Shear Braces are part of the overall lateral-force-resisting system of the
structure. The design of this system, including a complete load path necessary
to transfer lateral forces from the structure to the ground, is the responsibility of
the design professional of record.
AC130 cyclic testing in the lab.
7⁄8" anchor bolt holder and
15⁄16" wrench for 12" and 18" iSBs
1" anchor bolt holder and
11/2" wrench for 24" iSBs
iLevel® Shear Brace Specifier’s Guide TJ-8620
January 2009
5
ALLOWABLE DESIGN LOADS—STANDARD BRACE
Allowable Design Loads(1)­—Standard Brace on Concrete Foundation
Seismic Design
Brace (2)
Width
Height
Total
Vertical
Load
(lbs)
iSB 12x8
iSB 12x9
iSB 12x10
iSB 12x11
iSB 12x12
iSB 18x8
iSB 18x9
iSB 18x10
iSB 18x11
iSB 18x12
iSB 24x8
iSB 24x9
iSB 24x10
iSB 24x11
iSB 24x12
12"
12"
12"
12"
12"
18"
18"
18"
18"
18"
24"
24"
24"
24"
24"
931/4"
1051/4"
1171/4"
1291/4"
1411/4"
931/4"
1051/4"
1171/4"
1291/4"
1411/4"
931/4"
1051/4"
1171/4"
1291/4"
1411/4"
4,500
4,500
4,500
4,500
4,500
8,000
8,000
8,000
8,000
8,000
8,000
8,000
8,000
8,000
8,000
Allowable
Shear
(lbs)
905
790
605
545
485
2,215
1,905
1,725
1,530
1,340
4,435
3,905
3,325
3,010
2,695
Wind Design
Holdown
Drift at
Uplift
Allowable
Allowable at Allowable
Shear
Shear
Shear (3)
(lbs)
(in.)
(lbs)
0.38
0.43
0.49
0.54
0.59
0.37
0.43
0.48
0.53
0.59
0.37
0.42
0.47
0.52
0.57
Vertical Loads
(lbs)
8,440
8,315
7,095
7,045
6,850
12,910
12,530
12,640
12,360
11,830
18,800
18,680
17,720
17,685
17,305
995
890
665
600
535
2,435
2,090
1,895
1,685
1,475
4,880
4,295
3,660
3,315
2,965
Holdown
Drift at
Uplift
Allowable at Allowable
Shear
Shear (3)
(in.)
(lbs)
0.52
0.59
0.54
0.60
0.65
0.44
0.51
0.57
0.64
0.70
0.42
0.47
0.53
0.59
0.64
Allowable
Shear
Loads
(lbs)
9,280
9,370
7,795
7,755
7,555
14,200
13,750
13,905
13,600
13,015
20,685
20,550
19,505
19,475
19,035
(1) Interpolation of design values is allowed for custom height braces. For braces less than 93¼" tall, use the values for a 93¼" tall brace.
(2) 12" wide braces, 105¼" tall and less, and all 18" wide braces are allowed in prescriptive applications.
(3) Holdown Uplift at Allowable Shear is based on an assumed moment-arm equal to the brace width minus 2".
Front View
General Notes
Allowable Design Loads table is based on:
–160% load duration. No further increases for duration of load are permitted.
– iSB height of 89¾" to 141¼".
–ASTM A449 or ASTM A193-B7 threaded rod for anchorage; 1" diameter for 24"
wide braces, 7⁄8" for all others. See page 16 for other options.
■
Vertical Loads
(lbs)
Allowable Out-of-Plane Lateral Loads (PSF)
Attached to
Double Top
Plate (1)
Attached to
Header (1)(2)(3)
Brace
Width
12"
18"
24"
12"
18"
24"
8'
305
300
300
230
155
115
Standard Brace Height
9'
10'
11'
210
150
110
210
150
110
210
150
110
205
150
110
135
125
110
105
95
85
12'
85
85
85
85
85
75
Out-of-Plane
Lateral Loads
(psf)
(1) Based on 160% load duration. No further increases for duration of load are
permitted.
(2) Table values based on using iLevel® Portal Kit to resist header overturning.
(3) Load reduction factors:16" deep headers = 0.88
18" deep headers = 0.78
General Notes
Allowable Out-of-Plane Lateral Loads table is based on:
–Braces used in a s­ tandard application with or without a Raised Floor Kit and
installed according to the details in this guide.
– Wall deflection of L/240.
–Header depth of 14".
■
■
Side View
Out-of-plane lateral loads consider the total vertical load.
6
iLevel® Shear Brace Specifier’s Guide TJ-8620
January 2009
ALLOWABLE DESIGN LOADS—BRACES ON RAISED FLOOR KITS (RFK)
Allowable Design Loads(1)­—Standard Brace on Raised Floor Kit
Seismic Design
Brace (2)
Width
Height
Total
Vertical
Load
(lbs)
iSB 12x8
iSB 12x9
iSB 18x8
iSB 18x9
iSB 18x10
iSB 18x11
iSB 18x12
12"
12"
18"
18"
18"
18"
18"
931 ⁄4"
1051 ⁄4"
931 ⁄4"
1051 ⁄4"
1171 ⁄4"
1291 ⁄4"
1411 ⁄4"
4,500
4,500
8,000
8,000
8,000
8,000
8,000
Allowable
Shear
(lbs)
815
690
2,025
1,670
1,475
1,170
890
Wind Design
Holdown
Drift at
Uplift
Allowable
Allowable at Allowable
Shear
Shear
Shear (3)
(lbs)
(in.)
(lbs)
0.47
0.52
0.45
0.51
0.57
0.62
0.68
Vertical Loads
(lbs)
7,600
7,265
11,800
10,985
10,810
9,480
7,930
Holdown
Drift at
Uplift
Allowable at Allowable
Shear
Shear (3)
(in.)
(lbs)
895
760
2,225
1,840
1,620
1,290
985
0.61
0.66
0.56
0.63
0.70
0.76
0.83
Allowable
Shear
Loads
(lbs)
8,360
7,990
12,985
12,085
11,890
10,425
8,725
(1) Interpolation of design values is allowed for custom height braces. For braces less than 93¼" tall, use the values for a 93¼" tall brace.
(2) 12" wide braces, 105¼" tall and less, and all 18" wide braces are allowed in prescriptive applications.
(3) Holdown Uplift at Allowable Shear equals the uplift generated from the shear brace plus the uplift generated from the raised floor
kit. Uplift numbers do not include any consideration of shear from the floor diaphragms; this check is the responsibility of the design
­professional of record. Holdown uplift at allowable shear is based on the following assumptions:
Brace: moment arm = brace width minus 2".
Raised Floor Kit: moment arm = RFK width minus 31⁄2".
General Notes
Allowable Design Loads table is based on:
–160% load duration. No further increases for duration of load are permitted.
– iSB height of 89¾" to 141¼" (not including RFK).
–ASTM A449 or ASTM A193-B7 threaded rod for anchorage; 1" diameter for 24"
wide braces, 7⁄8" for all others. See page 16 for other options.
■
■
Front View
All kits use 31/2" wide TimberStrand® LSL blocks with pre-installed steel plates.
For floor systems 91/2" to 16" deep:
–RFK height = joist height + 21/4" (assuming a 11/2" sill plate and 3/4" floor
sheathing)
– RFK width = shear brace width + 3"
■
■
■
As an alternative to using the RFK, attach braces directly to concrete (as in
detail SB9 on page 13). Use the Allowable Design Loads—Standard Brace on
Concrete Foundation table on page 6 with this detail.
Vertical Loads
(lbs)
RFKs are for use only in single-story, non-portal applications.
Allowable Out-of-Plane Lateral Loads(1) (PSF)
Attached to Double
Top Plate
Brace
Width
12"
18"
8'
305
300
Standard Brace Height
9'
10'
11'
210
150
110
210
150
110
12'
85
85
Out-of-Plane
Lateral Loads
(psf)
(1) Based on 160% load duration. No further increases for duration of load are
permitted.
General Notes
A llowable Out-of-Plane Lateral Loads table is based on:
–Braces used in a r­ aised floor application installed according to the details in
this guide.
– Wall deflection of L/240.
■
■
Out-of-plane lateral loads consider the total vertical load.
iLevel® Shear Brace Specifier’s Guide TJ-8620
Side View
January 2009
7
PORTAL FRAME ASSEMBLY
Single Portal
Use one strap on
each side with a
minimum uplift
capacity of 500 lbs
per strap
Pre-cut hole for
light fixture
Portal straps 1⁄2" from
edges on both sides
of the brace (4 straps
total per brace)
,
pan
ar s 6"
e
l
m c 18'Bea 8' to
Pre-cut
wiring chase
Double Portal
Portal straps 1⁄2" from
edges on both sides
of the brace (4 straps
total per brace)
Column base with
a minimum uplift
capacity of 1,000 lbs
Concrete design is the
­responsibility of the
design professional
of record
Portal straps 1⁄2" from
edges on both sides
of the brace (4 straps
total per brace)
,
pan
ar s 6"
e
l
m c 18'Bea 8' to
Pre-cut hole for
light fixture
Pre-cut
wiring chase
Concrete design is the
­responsibility of the
design professional
of record
PORTAL DESIGN information
Using Shear Braces in Portal Frame Assemblies
The portal shear braces listed in the Allowable Design Loads—Portal on Concrete
Foundation table on page 9 require the brace-to-header connection detail shown
throughout this guide. Increased shear capacity due to the portal acting as a system
has been accounted for in the Allowable Shear values.
When designing portals using braces taller than 93¼" or wider than 18", use the
Allowable Shear values from the Allowable Design Loads—Standard Brace on
Concrete Foundation table on page 6. To achieve the Attached to Header values
shown in the Allowable Out-of-Plane Lateral Loads tables on pages 6 and 9, braces
must be attached to the header using the supplied screws and Portal Kit straps. Any
alternative connections designed by a professional of record should consider shear,
header overturning, and lateral out-of-plane capacities.
■
For Portal Installation Details, see page 14.
■
For drilling and trimming information, see pages 12 and 14.
8
Portal Header Design
■
Header width must be 31⁄8" minimum and 51⁄2" maximum.
■
Header depth must be 91⁄4" minimum and 18" maximum.
Induced Forces
A portal frame under lateral loads causes the portal header to experience internal
stresses in addition to those created by the primary loads (like gravity and wind).
These additional stresses are called induced forces and must be considered when
designing portal headers.
For headers with typical residential uniform loads, the induced moment and shear
forces from a portal frame system do not control the design. This is due to the
160% duration of load (DOL) factor used in design and the location of the induced
stresses. See ICC ES ESR-2652 for more information.
iLevel® Shear Brace Specifier’s Guide TJ-8620
January 2009
ALLOWABLE DESIGN LOADS—PORTAL FRAME
Allowable Design Loads(1)—Portal on Concrete Foundation
Single
Double
Portal Brace (2)
Assembly
iSB 12x7
iSB 12x7.5
iSB 12x8
iSB 18x7
iSB 18x7.5
iSB 18x8
iSB 12x7
iSB 12x7.5
iSB 12x8
iSB 18x7
iSB 18x7.5
iSB 18x8
Width
12"
12"
12"
18"
18"
18"
12"
12"
12"
18"
18"
18"
Total
Vertical
Height Load per Allowable
Shear
Brace
(lbs)
(lbs)
78"
851/2"
931/4"
78"
851/2"
931/4"
78"
851/2"
931/4"
78"
851/2"
931/4"
8,000
8,000
8,000
8,000
8,000
8,000
8,000
8,000
8,000
8,000
8,000
8,000
Seismic Design
Holdown
Drift at
Uplift
Allowable
Allowable at Allowable
Shear
Shear
(3)
Shear
(lbs)
(in.)
(lbs)
2,730
2,520
2,310
5,600
5,380
5,150
1,300
1,200
1,100
2,800
2,625
2,450
0.29
0.32
0.35
0.30
0.34
0.37
0.27
0.31
0.35
0.31
0.33
0.36
Vertical Loads
(lbs)
Wind Design
8,520
8,620
8,620
12,285
12,925
13,510
8,115
8,220
8,210
12,285
12,625
12,855
3,000
2,770
2,540
6,160
5,910
5,665
1,430
1,320
1,210
3,080
2,885
2,695
Holdown
Drift at
Uplift
Allowable at Allowable
Shear
Shear (3)
(in.)
(lbs)
0.31
0.35
0.39
0.33
0.37
0.40
0.33
0.38
0.42
0.36
0.40
0.43
9,370
9,480
9,480
13,515
14,220
14,860
8,925
9,040
9,030
13,515
13,890
14,140
Allowable
Shear
Loads
(lbs)
(1) Interpolation of design values is allowed for custom height braces. For braces less than 78" tall, use the values for a 78" tall brace.
(2) 12" wide braces, 105¼" tall and less, and all 18" wide braces are allowed in prescriptive applications.
(3) Holdown Uplift at Allowable Shear is based on an assumed moment-arm equal to the brace width minus 2".
General Notes
Allowable Design Loads table is based on:
– 160% load duration. No further increases for duration of load are permitted.
– iSB height of 741/2" to 931/4".
–ASTM A449 or ASTM A193-B7 threaded rod for anchorage; 1" diameter for 24"
wide braces, 7⁄8" for all others. See page 16 for other options.
–Portal header clear spans of 8' (minimum) to 18'-6" (maximum).
Allowable Shear and Drift at Allowable Shear are for the entire portal assembly.
■
Front View
■
■
Portal frame assemblies are not for use on RFKs.
■
For shimming and furring requirements, see details on page 14.
■
Portal braces may be used in 2x4 or 2x6 wall framing.
Vertical Loads
(lbs)
Allowable Out-of-Plane
Lateral Loads(1)(2)(3) (PSF)
Attached to
Header
Brace
Width
12"
18"
Portal Brace Height
7'
7.5'
8'
275
255
230
185
170
155
(1) Based on 160% load duration. No further
increases for duration of load are permitted.
(2) Table values based on using iLevel® Portal Kit to
resist header overturning.
(3) Load reduction factors:16" deep headers = 0.88
18" deep headers = 0.78
Out-of-Plane
Lateral Loads
(psf)
General Notes
Allowable Out-of-Plane Lateral Loads table is based on:
–Braces used in a p­ ortal application installed according to the details in
this guide.
– Wall deflection of L/240.
–Header depth of 14" in a portal system application.
■
■
Out-of-plane lateral loads consider the total vertical load.
iLevel® Shear Brace Specifier’s Guide TJ-8620
Side View
January 2009
9
allowable design loads—STACKED SHEAR BRACES
Allowable Design Loads(1) for Standard Brace in
2nd Floor, Stacked Application
Brace
Width
Height
Total
Vertical
Load
(lbs)
iSB 18x8
iSB 18x9
iSB 18x10
iSB 24x8
iSB 24x9
iSB 24x10
18"
18"
18"
24"
24"
24"
931 ⁄4"
1051 ⁄4"
1171 ⁄4"
931 ⁄4"
1051 ⁄4"
1171 ⁄4"
2,000
2,000
2,000
2,000
2,000
2,000
Seismic Design
Wind Design
Allowable
Shear (2)
(lbs)
Drift at
Allowable
Shear
(in.)
Allowable
Shear (2)
(lbs)
Drift at
Allowable
Shear
(in.)
1,235
1,120
1,000
1,855
1,770
1,690
0.43
0.48
0.54
0.33
0.35
0.39
1,420
1,285
1,150
1,855
1,770
1,690
0.47
0.53
0.59
0.33
0.35
0.39
V2
(1) Based on 160% load duration. No further increases for duration of load are permitted.
(2) Interpolation of design values is allowed for custom height braces. Minimum brace height of 93¼" required.
h3
Allowable Design Loads(1) for STK Brace in
1st Floor, Stacked Application
STK Brace
Width
Height
Total
Vertical
Load(2)
(lbs)
iSB 18x8-STK
iSB 18x9-STK
iSB 18x10-STK
iSB 18x11-STK
iSB 18x12-STK
iSB 24x8-STK
iSB 24x9-STK
iSB 24x10-STK
iSB 24x11-STK
iSB 24x12-STK
18"
18"
18"
18"
18"
24"
24"
24"
24"
24"
931 ⁄4"
1051 ⁄4"
1171 ⁄4"
1291 ⁄4"
1411 ⁄4"
931 ⁄4"
1051 ⁄4"
1171 ⁄4"
1291 ⁄4"
1411 ⁄4"
4,000
4,000
4,000
4,000
4,000
4,000
4,000
4,000
4,000
4,000
Seismic Design Wind Design
Allowable
Shear (3)
(lbs)
Allowable
Shear
(lbs)
2,215
1,905
1,725
1,530
1,340
4,435
3,905
3,325
3,010
2,695
2,435
2,090
1,895
1,685
1,475
4,880
4,295
3,660
3,315
2,965
V1 h2
h1
(1) Based on 160% load duration. No further increases for duration of load are permitted.
(2) Maximum axial load = second floor axial load (2,000 lbs) + first floor axial load
(4,000 lbs) = 6,000 lbs.
(3) Interpolation of design values is allowed for custom height braces. Minimum brace
height of 93¼" required. First floor braces in stacked applications may NOT be trimmed.
Allowable Reactions at Footing for
Stacked Brace Applications
Brace
Width
18"
24"
Design
Category
Wind
Seismic
Wind
Seismic
Maximum
Total Uplift
(lbs)
23,040
19,790
23,040
21,450
Maximum Base
Overturning ­Moment
(in.-lbs)
368,640
316,640
506,880
471,900
■
■
■
The maximum reactions for footings shown on this page are based on A449
threaded rod and the information on page 16. Other footing details may
change the allowable design loads and therefore require analysis by a design
professional.
Stacked shear braces may not be used with a raised floor kit. Instead, use an
iLevel® Shear Brace on the first floor that will extend the height of the wall and
floor system. See detail SB9 on page 13.
Maximum joist depth between stacked braces is 16".
STK-designated braces are required on the first floor of stacked-brace
applications.
■
The second floor brace must match the width of the first floor brace.
■
See page 15 for installation details.
10
Shear capacities shown are for individual braces only. To resist
forces at both upper and lower floors in a two-story a­ pplication, check
the shear at each floor against the maximum capacity for EACH brace.
Check the overturning moment (OM) against the maximum capacity
for the system. See page 11 for an example.
OM = (V2h2) + (V1h1)
Drift Equation for Lower Braces
General Notes
■
Vbase
2
Δ = h1 (3V1h3 + 2Vbase h1)
K
Δ . . . . . . . . . . deflection at the top of the lower brace (in.)
h1 . . . . . . . . . . lower brace height (in.)
h3 . . . . . . . . . . upper brace height (in.)
V1 . . . . . . . . . . applied shear load on lower brace (lbs)
V2 . . . . . . . . . . applied shear load on upper brace (lbs)
Vbase. . . . . . . . . V1 + V2 (lbs)
K . . . . . . . . . . 15.5 x 109 for 18" wide braces
36.7 x 109 for 24" wide braces
iLevel® Shear Brace Specifier’s Guide TJ-8620
January 2009
overturning forces
Designing for Overturning Forces
When specifying stacked shear brace applications, it is important to consider
overturning forces. Analysis should be performed by following these steps:
Vertical Load
V2 =
600 lbs
V2
1.Analyze the structure to determine the shear forces at each floor. Figure 1
illustrates the forces developed in a stacked shear brace.
2.Select an iLevel® Shear Brace for each floor, and verify that the shear capacity of
the brace meets or exceeds what is required. See below for more information.
h2
3.Calculate the system’s overturning moment and shear.
iSB 18x8
Shear Brace
4. Compare the required forces to the iLevel® Shear Brace capacity.
Calculating the Overturning Resistance of a
Stacked Shear Brace
The maximum overturning resistance provided by an iLevel® Shear Brace depends on
the footing capacity, the anchor bolt capacity, and the brace capacity. For all iLevel®
Shear Braces, the footing capacity controls. Concrete-footing uplift capacities are
based on the footing width, the anchor bolt embedment depth, and the loading
condition. See pages 10 and 16.
V1 =
1,200 lbs
V1
h1
Vbase. . . . . . . . . shear at footing
V1 . . . . . . . . . . shear at the top of the first floor brace
iSB 18x9 STK
Shear Brace
V2 . . . . . . . . . . shear at the top of the second floor brace
h1 . . . . . . . . . . height to top of the first floor brace
Vbase =
1,800 lbs
Vbase =
h2 . . . . . . . . . . height to top of the second floor brace
OM
w . . . . . . . . . . width of brace
U
OM. . . . . . . . . . base overturning moment
U . . . . . . . . . . uplift (tension in brace anchorage)
C . . . . . . . . . . compression (compression in brace anchorage)
U
C
16,003
Figure 1
Elevation of stacked braces, and the structural forces
developed during lateral events.
Design Example
V2 =
600 lbs
h2
Given
h2 =
216.25"
iSB 18x8
Shear Brace
■
Uncracked concrete
■
SDC B; Wind Speed = 100 mph (wind controls)
■
■
■
V1 =
1,200 lbs
■
h1 =
105.25"
iSB 18x9 STK
Shear Brace
Vbase =
1,800 lbs
U
C
16,003 lbs
OM =
256,050
in.-lb
First story wall height = 9'; shear brace choice = iSB 18x9
STK
Second story wall height = 8'; shear brace choice = iSB 18x8
Upper brace shear, V2 = 600 lbs
Lower brace shear, V1 = 1,200 lbs
Shear at footing, Vbase = 1,800 lbs
Floor joist depth = 14", and the total floor depth = 14" + 3/4"
+ 2 (11/2") = 173/4"
Solution
3Calculate the required overturning moment (OM) using the
shear at each story and the story heights:
OM = (V2h2) + (V1h1)
OM = (600 x 216.25) + (1,200 x 105.25) = 256,050 in.-lb.
4Compare the allowed maximum base overturning moment
(from step 1) to the required overturning moment. If the
capacity is exceeded, consider adding an additional brace to
the first story.
368,640 in.-lb > 256,050 in.-lb required. OK.
The stacked iSB 18x9-STK and iSB 18x8 are adequate to
resist the overturning and shear forces in this example.
Verify the footing requirements for the stacked shear braces.
From page 16, a 28" footing that has a C3 of 14" and an of
10" is required.
1From the Allowable Reactions at Footing for Stacked
Brace Applications table on page 10, the maximum base
overturning moment (OMmax) is: 368,640 in.-lb.
2Compare the shear at each brace to the maximum allowable
shear for each brace shown in the tables on page 10.
Second floor brace: Allowable shear for an iSB 18x8 =
1,420 lbs > 600 lbs required. OK.
First floor brace: Allowable shear for an iSB 18x9 STK =
2,090 lbs > 1,800 lbs (1,200 + 600 lbs) required. OK.
iLevel® Shear Brace Specifier’s Guide TJ-8620
January 2009
11
INSTALLATION DETAILS, trim zones, and allowable holes
Standard iLevel® Shear Brace Installation
Allowable Small Holes
Two top plates
or as specified
No holes
allowed in
top 8"
Optional OSB shim,
7⁄8" ­maximum
OPTION A
63⁄4" lag screws, provided:
6 with 12" brace (3 front, 3 back)
8 with 18" brace (4 front, 4 back)
12 with 24" brace (6 front, 6 back)
Start screws 31⁄2" (±1⁄2")
from bottom of double
top plate or header
31⁄2" (±1⁄2")
Optional OSB shim, 7⁄8" max.
For trim
zones, see
below
EDGE DRILL ZONE
Middle 1⁄3 of brace
thickness
■
■
■
Verify brace
is plumb
Do not install
screws in
­electrical chase
from either side
FACE DRILL ZONE
Maintain 11⁄2" min.
edge ­distance from
chase and ­outside
edge, ­typical
HOLES
Maximum three
holes in face and
three in edge
3⁄4" diameter
holes, maximum
6" o.c. minimum
■
Countersink (1⁄4" deep x
1" dia.) and install at an
angle that prevents screws
from exiting sides of top
plates or header. Offset
screws 1⁄2" front to back
to avoid ­interference. An
installation template is
available from your iLevel
­representative.
■
■
No holes
allowed in lower
40" of brace
Install nut
­finger-tight plus
1/8 turn, min.
Hardened
nut
Holdown
Threaded rod
Washer
Ensure concrete is level and
smooth beneath brace. Grind
and fill as necessary.
Anchor bolt
spacer
SB2
Allowable Large Holes for Standard and STK iSBs
(in addition to allowed small holes above)
Foundation system design
is the responsibility of
the design professional
of record
OPTION B
63⁄4" lag screws, provided,
installed from the top:
6 with 12" brace
8 with 18" brace
12 with 24" brace
No holes
allowed in
top 8"
FACE DRILL ZONE
Center of brace face
as shown
■
■
Optional OSB shim,
7⁄8" ­maximum
■
HOLES
45⁄8" diameter
holes, maximum
Maximum two 45⁄8"
holes or one 41/4" x
12" hole
No minimum
on‑center spacing
required
■
Optional OSB
shim, 7⁄8"
­maximum
For trim
zones, see
below
■
■
SB1
Do not install screws in
electrical chase
Trim Zones
Trim height from the top of the brace only. Do not trim the sides or bottom.
■
DO NOT trim the bottom brace in a stacked brace application.
■
31⁄2" maximum allowable trim for portal braces.
■
12" and 18" standard braces taller than 93¼" may be trimmed down to a
minimum height of 741/2".
■
24" braces may be trimmed down to a minimum height of 893/4".
■
12
SB11
iLevel® Shear Brace Specifier’s Guide TJ-8620
January 2009
Minimum 12"
above existing hole
RAISED FLOOR DETAILS
RFK Installation
RFK Interior View
❶ Thread the ported coupler nuts
and threaded rods onto anchor
bolts
Notch floor sheathing
around brace
❷ Lower block onto threaded rods
and swing bottom of block and
spacer plates into place
❸ Install iLevel® Shear Brace on
block
RFK block
TJI® joist
11/4" TimberStrand® LSL
or iLevel® 11/8" rim board
Top shear-transfer plate
(pre-attached)
Attach USP MP4F framing anchor
with 0.148" x 11/2" nails. Fill all
nail holes.
Joist
hanger
Ledger
Foundation system design is
the responsibility of the design
professional of record
31⁄2" TimberStrand® LSL RFK block (face
grooved side to exterior of building)
Bottom shear-transfer plate
(pre-attached)
7⁄8"
diameter threaded rod
7⁄8"
ported coupler nut
Sill plate
Sill plate anchor
bolt (per code)
SB8 Not applicable for 24" shear braces
In-line Shear Brace
Raised
Floor Kit
iLevel® Shear Brace sized
to include the floor system
height and installed
directly on the foundation
Steel shim
11/2"
Foundation system design
is the ­responsibility of
the design professional of
record
11/4" TimberStrand®
LSL or iLevel® 11/8"
rim board
TJI® joist
Sill plate
11/2" minimum clearance
required on each side of
the anchor bolt spacer to
accommodate the RFK
Ledger
SB9
SB7 Not applicable for 24" shear braces
Joist
hanger
Sill plate anchor
bolt (per code)
Foundation system design is
the responsibility of the design
professional of record
General Notes
■
■
■
DO NOT modify the Raised Floor Kit. For floor assemblies of non-standard heights
(such as floor sheathing thicker than 3⁄4", sill plates thicker than 11⁄2", or floor
joists different than standard TJI® joist depths), adjust the total assembly height
with steel shims or by trimming at the top of the iLevel® Shear Brace.
Place the Raised Floor Kit directly on the concrete. DO NOT place on top
of the sill plate.
Attach floor joists to the RFK block using approved joist hangers. Alternatively,
joists may rest on the remaining sill plate if adequate bearing is available.
■
■
Notch floor sheathing around RFK block and iLevel® Shear Brace. Support the
floor sheathing with a ledger attached directly to the block or iLevel® Shear Brace
(depending on elevation requirements) to accommodate vertical loads and lateral
load transfer. Use connections equivalent to the floor sheathing nailing schedule.
The iLevel® Shear Brace must sit directly on the RFK top shear-transfer plate.
Using compressible materials such as sheathing or wood shims in this area will
affect the performance of the assembly.
iLevel® Shear Brace Specifier’s Guide TJ-8620
January 2009
13
PORTAL INSTALLATION DETAILS
Portal Frame Shear Brace
Portal Frame Column
31⁄2" wide x 91⁄4"–18" deep header as
specified. See SB5 for other header
widths and allowable furring.
Header as specified.
For 51⁄4" or 51⁄2" header,
use furring as required.
See detail SB5 below.
Optional OSB shim, 7⁄8" ­maximum
Portal straps (provided): Maintain 1/2" minimum edge
­distance. Attach with sixteen 0.148" x 23∕8" minimum nails,
8 into header and 8 into Shear Brace
63⁄4" lag screws, provided:
6 with 12" brace (3 front, 3 back)
8 with 18" brace (4 front, 4 back)
12 with 24" brace (6 front, 6 back)
■
■
Use a strap on each side
with a minimum uplift
capacity of 500 lbs per
strap
Do not install screws
in electrical chase
from either side
■
Start screws 31⁄2" (±1⁄2") from bottom
of double top plate or header
Verify brace
is plumb
Optional OSB shim, 7⁄8" max.
31⁄2" (±1⁄2")
Hardened
nut
Washer
SB3
TimberStrand® LSL portal
column or solid sawn column
(3" x 3½" minimum) per the
design professional of record
(trim as required)
Install nut ­finger-tight
plus 1/8 turn, min.
Countersink (1⁄4" deep x 1" dia.) and install
at an angle that prevents screws from exiting
sides of top plates or header. Offset screws
1⁄2" front to back to avoid ­interference. An installation template is available from your iLevel
­representative.
Holdown
Column base with a
minimum uplift capacity
of 1,000 lbs
Threaded rod
Ensure concrete is level and smooth beneath
brace. Grind and fill as necessary.
Anchor bolt spacer
Foundation system design
is the responsibility of
the design professional
of record
Foundation system design is the
­responsibility of the design professional
of record
SB4
Portal Trim Zone
Trim height from the top of the brace only. Do not trim the sides or bottom.
■
31⁄2" maximum allowable trim for portal braces.
■
Portal Frame Shear Brace with 51⁄4" or 51⁄2" Wide Header
(Similar for 31⁄8" header)
91⁄4"–18" deep header as specified.
Center over brace width.
Minimum 21⁄2" x 10" furring of 7⁄8" thick OSB.
Attach furring to brace with ten 0.131" x 21/2"
nails. With 31⁄8" wide headers, attach furring
to header.
Portal straps (provided): Maintain
1/2" minimum edge distance. Attach
with sixteen 0.148" x 23∕8" min. nails,
8 into header and
8 into Shear Brace
Connect header to brace with 63⁄4" lag screws (provided):
6 with 12" brace (3 front, 3 back)
8 with 18" brace (4 front, 4 back)
12 with 24" brace (6 front, 6 back)
■
■
■
SB5
14
iLevel® Shear Brace Specifier’s Guide TJ-8620
January 2009
MULTISTORY KIT Installation DETAILS
Stackable Brace Assembly
➏ Place brace over threaded rod. Install
round washer and nut finger-tight
plus ¹⁄8 turn, minimum.
❺ Install nut, then 3" x 3" washer so that
the top of washer is flush with the top
of flooring
➍ Hand tighten rod until 13/4"–23/4"
➐ Install 2 layers of full-depth-and-
remains above the sheathing
❸ Cut 31/2" x 31/2" notches in flooring. ­Notching rim board on
the inside may be required to
­accommodate rods.
❷ 7⁄8" diameter threaded rod (1" dia. with 24"
14"
brace). Drill holes through double top plate for
rods. Make holes ¹⁄8" larger than threaded rod.
width, solid blocking under entire
width of brace. See Rimboard
Detail below. Nail with 0.148" x 3"
nails. Use:
– Three nails per ply on narrow section
– Three rows of four nails each in
­center section
0"
or 2
❶ Place holdowns on the lower shear brace.
Verify that bolt-hole centers are 14"
apart for 18" braces or 20" apart
for 24" braces. Nail using the
provided nails.
Lower brace must be an
­STK-designated, stackable brace
Welded nut pre-installed
on multistory holdowns
SB
10
DO NOT trim lower shear brace in a stacked brace
application. Maximum allowable shim is 7⁄8" thick and
must be installed between the holdown brackets and
the double top plate.
Not applicable for 12" shear braces
Outside View of Connection
Rimboard Detail
Notching rim may be
required for threaded rod,
depending on rim thickness
➑ Install T-plate with 0.148"
x 11/2" nails. Fill all nail
holes.
Notching rim may be
required for nut, depending
on floor thickness
Locate splice as required
11⁄8" max. floor
sheathing thickness
➒ Use three USP MP4F
framing anchors. Fill all
holes with 0.148" x 11/2"
nails.
Threaded
rod
iLevel® Shear Brace Specifier’s Guide TJ-8620
Threaded
rod diameter
Use rim as
+ 1⁄8"
blocking
Blocking under entire width of brace
January 2009
15
anchorage embedment depths
General Notes for Anchorage
■
No increases for duration of load are permitted.
■
Anchorage embedment is based on ACI 318 Appendix D.
■
Appropriate for use in areas governed by IBC or IRC.
■
Concrete assumptions: Minimum f'c of 2,500 psi; Φ = 0.85 (condition A).
■
No special inspection per IBC 1704.1 or 1705.3.1 is required.
■
■
is measured from the top of the washer to the top of the footing.
For additional information, see ICC ES ESR-2652 and iLevel Shear Brace
Technical Bulletin (Reorder #TB-912).
Concrete Embedment Depths and Footing Dimensions for Threaded Rod(1)(2)(3)
Embedment Depth
Minimum Footing Dimensions
Seismic
Wind
C1
C2
C3
(SCD C-E)
7⁄ 8"
iSB 12x_
16"
6"
7"
6"
10"
10"
7⁄ 8"
16"
10"
N.A.
6"
10"
10"
iSB 18x_
Standard or
7⁄ 8"
22"
7"
8"
9"
13"
10"
Portal Braces
1"
25"
9"
N.A.
11"
14"
12"
Uncracked
iSB 24x_
Concrete
1"
28"
9"
10"
12"
16"
14"
7⁄ 8"
iSB 18x_ STK
28"
10"
10"
12"
16"
14"
Two-story or
1"
25"
10"
N.A.
11"
14"
12"
Stacked Braces iSB 24x_ STK
1"
30"
9"
11"
13"
17"
13"
21⁄8"
7⁄ 8"
iSB 12x_
22"
7"
8"
9"
13"
12"
Standard or
7⁄ 8"
28"
9"
9"
12"
16"
12"
iSB 18x_
Portal Braces
Concrete
Cracked
iSB 24x_
1"
32"
10" A
11" Stem wall 14"
18" wall height
16"
length
Concrete
7⁄ 8"
iSB 18x_ STK
36"
10"
13" 121⁄8" min.16"
20"
18"
Two-story or
Stacked Braces iSB 24x_ STK
1"
35"
10"
12"
16"
19"threaded 16"
Total
rod assembly
(1) Anchor bolts are ASTM A449 or ASTM A193 B7 threaded rod and are applicable for all braces and applications within this guide.C
length
2
Application
Brace
Anchor Bolt
Diameter
Minimum
­Footing Width
(2) ASTM A307 threaded rod may be substituted in all 12" wide brace applications.
(3) ASTM A307 threaded rod may be substituted for braces where the holdown uplift at allowable design shear is less than shown C1
in the following table:
Anchor Bolt
Diameter
7⁄ 8"
1"
■
Wind
15,200 lbs
19,900 lbs
Seismic
(SCD C-E)
11,400 lbs
14,900 lbs
C3
C3
Anchor bolt
spacer A
A
C3 is measured from the end of the template.
C2
Stem wall
per code
13⁄4" (min.)
21⁄8"
Footing
Stem wall length
121⁄8" min.
13⁄4" (min.)
Concrete
wall height
Stem wall
per code
C1
C2
Footing
width per code
Total threaded
rod assembly
length
C1
Foundation systems are the
­responsibility of the design professional
of record.
C3
C3
Anchor bolt
spacer
A
Footing
C1
C2
Footing
width per code
Section A–A
alternate anchorage for 12" shear braces
13⁄4" (min.)
Alternate Anchorage
For 12" iLevel® Shear Braces
Anchor
Manufacturer
STB28
SSTB28
SSTB34
USP
Simpson
Simpson
Embedment
Depth,
257⁄ 8"
257⁄ 8"
317⁄ 8"
#4 rebar
21⁄8"
Anchor Bolt Spacer
Required
Yes
Yes
Yes
Stem wall
per code
Stem wall
8" x 18" min.
B
#4 rebar
13⁄4" (min.)
General Notes
■
Check with manufacturer for capacities and installation instructions.
Exception: Leave 21⁄8" of anchor bolt above the anchor bolt spacer.
■
Not for use with masonry walls.
■
Minimum concrete f'c of 2,500 psi.
■
Place jam nut on anchor bolt 21⁄8" from the top of the bolt.
#4 rebar
21⁄8"
5" min.
Anchor bolt
spacer
Footing design
B
by others
B ConcreteStem wall
Top View of
8" x 18" min.
Wall and Footing
Stem wall
per code
Footing
width per code
Section View of Concrete
#4 rebar
Wall and Footing
Section B–B
Anchor bolt
16
5" min.
B
spacer
iLevel® Shear Brace Specifier’s
Guide TJ-8620
Footing design
January
2009
by others
ANCHOR BOLT INSTALLATION
Anchor Bolt Installation
■
■
■
■
■
■
21⁄4"
On the bottom end of each rod create a double nut and washer assembly by
installing a washer between two hex nuts, leaving two threads showing at the
bottom.
On the top end of each rod, install a jam nut roughly 21/4" from the top. Set the
anchor bolt spacer on the jam nuts.
Grooves
Slide the iLevel® anchor bolt holder over the threads, flush with the end of the
threaded rod, and snap it shut (invert the anchor bolt holder depending on
concrete form layout).
Vertical faces
Grooves
Hand-tighten the jam nut to the underside of the anchor bolt spacer.
Nail the iLevel® anchor bolt assembly to the form edge using three nails
(alignment depends on header thickness).
To better secure the assembly during concrete placement, tie the threaded rods
to footing reinforcement.
Attachment for 4x_ Header
11⁄4"
Threaded Rod Assembly
Anchor Bolt Holder
Attachment to Center iSB Under 6x_ Header
Groove
Vertical face
To install shear brace
flush to the outside face
of wall, align bolt holder’s
vertical faces with inside
face of formwork
13⁄4"
To install shear brace
centered under 51⁄2" header
or beam, align bolt holder’s
grooves with inside face of
formwork
23⁄4"
iLevel® anchor bolt spacer
iLevel® anchor bolt holder
Total threaded rod
assembly length =
33⁄8" + + concrete
wall height
Threaded rod
Tie threaded rod to footing
reinforcement (recommended)
Double nut and
washer assembly
iLevel® Shear Brace Specifier’s Guide TJ-8620
January 2009
17
Anchorage details
Portal Anchorage at Garage Curb
A
2" (min.)
6" curb height, typ.
Concrete wall height per
code or plan (not part of )
C3
Brace width
C3
A
Jam nut below anchor
bolt spacer
6" curb height, typ.
Concrete wall height per
code or plan (not part of )
7⁄8" dia. (1" dia. with
24" iSB) threaded rod,
grade A449 or A193 B7
, top of footing
to top of washer
1
1 ⁄4" top of washer
to bottom of rod
3" min.
coverage
Stem wall per code
13 ⁄4" min.
Anchor bolt spacer
21 ⁄8"
, top of footing
to top of washer
3" min. coverage
#4 rebar per code or plan
Double nut and
washer assembly
C1
C2
Footing width
Section A–A
General Notes
■
For C1, C2, C3, and , see tables on page 16.
■
C3 is measured from the end of the template.
Foundation systems are the
­responsibility of the design professional
of record.
Concrete Foundation—Slab on Grade
B
2" min.
13⁄4" min.
Anchor bolt spacer
21 ⁄8"
Concrete wall height per
code or plan (not part of )
Concrete wall height per
code or plan (not part of )
7⁄8" dia. (1" dia. with
24" iSB) threaded rod,
grade A449 or A193 B7
, top of footing
to top of washer
11 ⁄4" top of washer
to bottom of rod
3" min.
coverage
Jam nut below
anchor bolt spacer
, top of footing
to top of washer
#4 rebar per code or plan
C3
Brace width
B
C3
Double nut and
washer assembly
C1
C2
Footing width
Section B–B
General Notes
■
For C1, C2, C3, and , see tables on page 16.
■
C3 is measured from the end of the template.
Foundation systems are the
­responsibility of the design professional
of record.
18
iLevel® Shear Brace Specifier’s Guide TJ-8620
January 2009
ANCHORAGE DETAILS
Concrete Foundation with Stem Wall or Basement
2" min.
13⁄4" min.
C
21⁄8"
Anchor bolt spacer
⁄ " dia. (1" with 24" iSB)
threaded rod, grade A449 or
A193 B7
Ported coupler, compatible
with A193 B7 threaded rod,
as required
Jam nut below
anchor bolt spacer
78
Concrete wall height per
code or plan (not part of )
Stem wall
per code
Concrete wall height per
code or plan (not part of )
Monolithic or
two-stage pour
Second anchor bolt
spacer recommended
for two-stage pour
#4 rebar per code or plan
Double nut and washer assembly
, top of footing
to top of washer
1
1 ⁄4" top of washer
to bottom of rod
3" min.
coverage
C3
, top of footing
to top of washer
Brace width C3
Jam nut below
anchor bolt spacer
C1
C2
Footing width
C
Section C–C
General Notes
■
For C1, C2, C3, and , see tables on page 16.
■
For a two-stage pour, a second anchor bolt spacer is recommended. See detail.
■
C3 is measured from the end of the template.
Foundation systems are the
­responsibility of the design professional
of record.
Concrete Masonry Wall for Prescriptive Use Only
(12" and 18" Braces Only)
Flat Anchor-Bolt-Spacer Bolt Locations
D
21⁄8"
12" iSB
Solid grouted wall section the width
of the brace plus 2", min. both sides.
Use 3,500 psi grout, min.
2"
2"
min.
min.
41⁄16"
(Use existing holes)
18" iSB
5"
5"
(Use existing holes)
⁄ " min. grout
clearance
12
Flat anchor bolt spacer
⁄ " dia. x 5" long bolt,
see details above
7⁄8" dia. threaded rod,
grade A449 or A193 B7
Jam nut below flat
anchor bolt spacer
12
CMU wall height per code
or plan (not part of ) le
8" min. CMU wall
with 3,500 psi min.
solid grout
CMU wall height per code
or plan (not part of l)
Ported coupler, compatible
with A193 B7 threaded rod,
as required
Anchor bolt spacer
recommended
, top of footing
to top of washer
11 ⁄4" top of washer
to bottom of rod
3" min.
coverage
, top of footing
to top of washer
Jam nut below
anchor bolt spacer
#4 rebar per code or plan
Double nut and washer assembly
C3
Brace width
C3
D
C1
C2
Footing width
Section D–D
General Notes
■
For C1, C2, C3, and , see tables on page 16.
■
For anchorage into CMU walls, the grout strength must be 3,500 psi, minimum.
Two anchor bolt spacers are recommended:
–Order flat anchor bolt spacer for CMU wall anchorage.
–Use standard anchor bolt spacer for concrete footing.
Foundation systems are the
­responsibility of the design professional
of record.
■
■
Notch bottom of shear brace (1/4" x 1" x 1") to accommodate carriage bolts.
■
C3 is measured from the end of the template.
iLevel® Shear Brace Specifier’s Guide TJ-8620
January 2009
19
WALL BRACING
What is Wall Bracing?
Criteria for Prescriptive Design
Wall bracing resists lateral (sideways) movement in a structure, and consists of a
system of specially constructed wall segments tied to the roof and floor.
The following conditions must be met in order to use prescriptive methods:
Prescriptive wall bracing requirements are commonly satisfied in one of four ways:
1.Construct 4'-wide wall sections of code-prescribed materials.
■
Wind speeds of less than 110 mph or less than 100 mph in hurricane regions.
■
Seismic design category (SDC) of A through D2.
■
2.Construct narrow wall sections (at least 28" wide) of OSB (oriented strand board)
or plywood and include tiedowns.
3.Use prefabricated wall sections designed to resist lateral loads.
4.Construct alternate site-built or prefabricated portal frame.
The most common panel materials used for wall bracing are 4' x 8' structural panels
(OSB or plywood) or gypsum board. However, iLevel® Shear Braces are strong enough
that any width of brace may replace any 4'-wide, site-built panel. Refer to section
IRC R602.10 for specifics on braced wall requirements and construction methods.
■
Additional restrictions apply based on loads and building geometry. See iLevel’s
Conventional Construction Guide (Reorder #1502) or contact your local building
official.
Some jurisdictions require an engineered design for all homes. Check with the
local building official to determine if a house plan requires an engineered design
or can be prescriptively specified.
Local wind speed and seismic categories can be obtained from your local building
official.
Most iLevel® Shear Braces can be counted
as 4' of bracing and are a 1-for-1
substitution for site-built shear wall sections.
Exception: 12" wide braces greater
than 105¼" tall
How to PRESCRIPTIVELY Specify Braced Panels
Procedure
1.Define the wall line to be braced. All portions of the wall line must be within 4' of
the braced wall line. See page 21.
2.Calculate how many panels are required to meet the 25' o.c. spacing requirement
by dividing the wall length by 25'. Always round up.
– If more than one braced wall panel is required, place the first two panels at, or
near, each end of the wall line. Then place any additional braced wall panels in
the remaining wall length as evenly spaced as possible.
– When a wall section does not provide sufficient length for a 4' braced wall
panel, try an iLevel® Shear Brace instead.
3. Adjust the panel locations at both ends of the wall line, if required.
– For exterior wall lines in SDC A–C, the distance from the end of the wall to the
nearest edge of a braced wall panel cannot be more than 12'-6".
20
– For exterior wall lines in SDC D0–D2, panels must be placed at the ends of the
wall line. Refer to IRC R602.10.11.2 for exceptions. Note: An iLevel® Shear
Brace may be located up to 8' from the end of the braced wall line in SDC
D0–D2.
4.Check the percentage of bracing provided. To do this, add together the widths of
all braced wall panels specified in step 2 (an iLevel® Shear Brace counts as 4' of
bracing regardless of its actual width). Divide the total panel width by the wall
length; then multiply by 100.
– If the resulting percentage is less than that required by IRC Table R602.10.1,
add additional bracing until the result meets or exceeds the requirement.
5.If a wall line cannot meet the bracing requirements following this procedure,
additional analysis may be required, or the wall line may need to be modified.
Contact your iLevel representative for assistance.
iLevel® Shear Brace Specifier’s Guide TJ-8620
January 2009
PRESCRIPTIVE BRACING REQUIREMENTS
17'-6"
1'-9"
8'-6"
1'-9"
Laying Out Braced Wall Lines
and Panels in a Typical House 32'-0"
17'-6"
2'-6"
1'-9"
Braced wall panels must occur at least
every 25' of the braced-wall line length
1'-9"
8'-6"
2'-6"
32'-0"
55'
1
Site-built panels must be
at least 4' long
19'
Wall or opening
Braced wall panels may
be offset no more than 4' 3'
from a braced wall line
6'
3'
2
9'
5'
2' 2' 2' 4'
3' 2'
8" 8"
Braced panel must start within
12'-6" of the end44'-4"
of a braced wall 4'
line (8'-0" for SDC D)
6'
3'
3'
2'
9'
2'
■
First story of a two story house.
■
Total exterior wall length = 41'-10".
2'
8" 8"
44'-4"
2'
4'
21'
2'
Braced wall lines may be
spaced up to 35' apart
5'
3' 2'
B
Braced wall lines, typical
C
PRESCRIPTIVE BRACE EXAMPLE
6'
3'
3'
2'
2' 2'
8" 8"
44'-4"
9'
2'
Determine the required bracing for the wall line shown:
5'
2'
2' 4'
3' 2'
8" 8" Legend
44'-4"
Opening in wall
Wall
Shear Brace locations
4' site-built panel
6'
7'-4"
9'
10'
4' 1'-6"
2'
3'
6'
2'
9'
41'-10"
Situation II
Seismic Design Category: Do
Wind Speed: 90 mph
1No portion of the braced wall line may be offset more than 4'. The offset is 3',
which meets the requirements. So the braced wall line is the total wall length of
41'-10".
1, 2, and 3 same as Situation I.
1'-9"
7'-4"
4' 1'-6"
10'
2'
41'-10"
Situation I
Seismic Design Category: A
Wind Speed: 100 mph
17'-6"
3'
3'
2'
3'
2'
3'
Identifies each braced wall line
for easier tracking5'
2' 3'
4'
3' 2'
3
3'
6'
9'
28'
A
Given3'
Code-accepted
braced wall panel
3'
8'-6"
2'-6"
2A braced wall panel is required every 25' of wall length. Find the number of
panels required.
32'-0"
3Place the panels to meet the 25' spacing and the 12'-6" end distance
requirements. Place one 4' site-built panel in the 9' long wall section. Position
the panel on the left side of the 9' section in order to meet the end distance
requirement of 12'-6" or less.
1'-9"
5 F or SDC D0, IRC Table R602.10.1 requires that at least 45% of the wall line
length be braced. Following the same procedure as Step 4 in Situation 1:
4' + 4' + 4' + 4' = 16' (16' ÷ 41'-10") x 100 = 38% 38% < 45% NOT OK!
There are no 4' long wall sections available on the right side of the wall line for
a site-built panel, so place one 12" iSB at the offset in the right side of the wall
section. Verify that the panels meet the 25' spacing and the 12'-6" end distance
requirements:
19'-4" < 25'
8' < 12'-6"
12' < 12'-6"
1'-9"
8'-
32'-0"
41'-10" ÷ 25' = 1.7. Rounding up, at least two panels are required.
The distance between panel centers is 19'-4"
The end distance for the site-built panel is 8'
The end distance for the iSB is 12'
17'-6"
4 H owever, for SDC D0, the panels must be at the ends of exterior wall lines. In
order to meet that requirement and the 25' spacing rule, braced panels will have
to be added rather than simply moved to the ends of the wall line. Therefore,
add a panel at the left and right ends of the wall. Since there isn’t space for 4'
panels, use two 12" iSBs. There are now four panels, and the distance between
panel centers remains less than 25'.
OK
OK
OK
4 F or SDC A, IRC Table R602.10.1 requires that at least 16% of the wall line length
be braced. Find the percentage of bracing provided by adding the panel widths
together and dividing by the wall length. Then multiply by 100. Remember: An
iSB is equivalent to 4' of bracing regardless of its actual width.
4' + 4' = 8'
(8' ÷ 41'-10") x 100 = 19%
19% > 16%
OK
6Determine how much additional bracing is needed. Multiply the percentage
required by the wall length: 0.45 x 41'-10" = 19'. 19' minus the existing 16'
equals 3' of additional bracing needed. One more panel will be sufficient.
7 T here are two options:
A) Add a second 4' braced panel in the 9' wall section.
B) Add a 4' braced panel in the 4' space near the offset.
While both options meet IRC provisions, choose option B and add a braced panel
near the offset.
The braced panel layout is complete.
3'
The braced panel layout is complete.
2'
8"
2'
8"
2'
4'
3' 2'
5'
2'
3'
3'
iLevel® Shear Brace Specifier’s Guide TJ-8620
6'
January 2009
9'
2'
8"
21 2'
2'
8"
PORTALS
One Double Portal
Two Single Portals
8'-0" min.
18'-6" max.
Panels
Headers
Quantity
2
1
8'-0" min.
18'-6" max.
24'-0" max.
Size
iSB 12x7, 7.5, or 8
See table below
Panels
Columns
Headers
One Single and One Double Portal
8'-0" min.
18'-6" max.
Panels
Columns
Headers
Quantity
2
2
2
Size
iSB 12x7, 7.5, or 8
31/2" x 31/2" x brace height
See table below
Three Single Portals
8'-0" min.
18'-6" max.
Quantity
3
1
2
8'-0" min.
18'-6" max.
8'-0" min.
18'-6" max.
8'-0" min.
18'-6" max.
8'-0" min.
18'-6" max.
24'-0" max.
Size
iSB 12x7, 7.5, or 8
31/2" x 31/2" x brace height
See table below
Panels
Columns
Headers
Quantity
3
3
3
Size
iSB 12x7, 7.5, or 8
31/2" x 31/2" x brace height
See table below
General Notes
■
■
Header must be single span. Do not run headers continuous over more than one
portal.
■
A minimum of 1,000 lbs of uplift capacity is required at the top and bottom of a
single, portal column.
To transfer shear across header joints in prescriptive applications, use one
LSTA 24 strap, minimum, (placed across the top for 91/2" deep headers) unless
the header is attached to a continuous double top plate.
PORTAL HEADER SIZING TABLE
How to Use This Table
1.Determine appropriate Roof Load and House Width.
2.Locate Rough Opening.
3.Select header size and material.
Minimum Header Size Required
Roof Load (PSF)
Non-Snow
Area
125%
20LL + 15DL
20LL + 20DL
25LL + 15DL
Snow
Area
115%
30LL + 15DL
40LL + 15DL
House
Width
24'
30'
36'
24'
30'
36'
24'
30'
36'
24'
30'
36'
24'
30'
36'
T 1.55E TimberStrand® LSL
22
9'-3"
31/2" x 91/4" T
31/2" x 91/4" T
31/2" x 91/4" T
31/2" x 91/4" T
31/2" x 91/4" T
31/2" x 91/4" T
31/2" x 91/4" T
31/2" x 91/4" T
31/2" x 91/4" T
31/2" x 91/4" T
31/2" x 91/4" T
31/2" x 91/4" T
31/2" x 91/4" T
31/2" x 91/4" T
31/2" x 91/4"
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
P
P
P
P
P
P
P
P
P
P
P
P
P
P
P
Rough Opening
16'-3"
31/2" x 14" T M
31/2" x 14" T M
31/2" x 14" T M
31/2" x 14" T M
31/2" x 14" T M
31/2" x 14"
M
31/2" x 14" T M
31/2" x 14" T M
31/2" x 14"
M
31/2" x 14" T M
31/2" x 14"
M
31/2" x 16" T M
31/2" x 14"
M
31/2" x 16"
M
51/4" x 14"
M
M 1.9E Microllam® LVL
P
P
P
P
P
P
P
P
P
P
P
P
P
P
P
18'-3"
31/2" x 14" T
31/2" x 14"
31/2" x 16" T
31/2" x 14"
31/2" x 16" T
31/2" x 16"
31/2" x 14"
31/2" x 16" T
31/2" x 16"
31/2" x 14"
31/2" x 16"
5 1/4" x 14"
31/2" x 16"
51/4" x 14"
51/4" x 16" T
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
P
P
P
P
P
P
P
P
P
P
P
P
P
P
P
P 2.0E Parallam® PSL
iLevel® Shear Brace Specifier’s Guide TJ-8620
January 2009
Rough
openin
g
Ho
e
us
h
dt
wi
PRESCRIPTIVE ANCHORAGE
Prescriptive Embedment Depths and Footing Dimensions
Application
Loading
­Condition
Standard or
Portal Brace
Wind, SDC A–B
SDC C–E
Wind
SDC A–B
SDC C–E
Stacked
Brace
Embedment
Minimum
Minimum
Minimum
Minimum
Length (1),
Footing Width
C1
C2
C3
(in.)
6"
16"
6"
10"
10"
See Concrete Embedment Depths table on page 16
10"
28"
12"
16"
12"
10"
28"
12"
16"
10"
10"
28"
12"
16"
14"
(1) Measured from the top of the footing to the top of the washer.
General Notes
■
■
■
■
■
13⁄4" (min.)
13⁄4" (min.)
Minimum concrete f'c of 2,500 psi.
Standard holdown anchors are 7⁄8" ASTM A449 or
ASTM A193-B7 threaded rod.
21⁄8"
21⁄8"
For 12" braces, A307-grade threaded rod may be
used with the embedment lengths shown.
A
A
F or 18" braces, A307-grade threaded rod may
be used with the embedment lengths shown, if
the brace is used in an SDC A or B application
(SDC for detached houses) and in a non-stacked
application.
C2
C2
C1
C1
C3
C3Anchor bolt
Anchor
spacerbolt
spacer A
A
C3 is measured from the end of the template.
Threaded Rod Installation
■
Stem wall length
1⁄8" wall
Stem
12
min.length
121⁄8" min.
C3
C3
Concrete
Concrete
wall
height
wall height
Total threaded
Total
threaded
rod assembly
rod length
assembly
length
Stem wall
Stemcode
wall
per
per code
Footing
Footing
C1
C2
CFooting
C2
1
Footing
width
per code
width per code
To ensure the proper on-center spacing of threaded
rods or anchor bolts, use an anchor bolt spacer on
a 7⁄8" jam nut. See details on page 17.
Section A–A
alternate anchorage for 12" shear braces
Alternate Anchorage
13⁄4" (min.)
13⁄4" (min.)
For 12" iLevel® Shear Braces
Anchor
Manufacturer
STB28
SSTB28
USP
Simpson
Embedment
Depth,
257⁄ 8"
257⁄ 8"
#4 rebar
#4 rebar
21⁄8"
21⁄8"
Anchor Bolt Spacer
Required
Yes
Yes
B
B
Stem wall
Stemcode
wall
per
per code
Stem wall
Stem
wallmin.
8"
x 18"
8" x 18" min.
General Notes
■
Check with manufacturer for capacities and
installation instructions. Exception: Leave 21⁄8" of
anchor bolt above the anchor bolt spacer.
■
Not for use with masonry walls.
■
Minimum concrete f'c of 2,500 psi.
■
Place jam nut on anchor bolt 21⁄8" from the top of
the bolt.
#4 rebar
#4 rebar
Anchor bolt
Anchor bolt
spacer
spacer
B
B
5" min.
5" min.
Footing design
Footing
by
othersdesign
by others
Top View of Concrete
Wall and Footing
Footing
width
per code
Footing
width per code
Section View of Concrete
Wall and Footing
Section B–B
iLevel® Shear Brace Specifier’s Guide TJ-8620
January 2009
23
WALL SOLUTIONS
WE CAN HELP YOU BUILD SMARTER.
At iLevel, our goal is to help you build solid and durable homes by providing high-quality residential building
products and unparalleled technical and field support.
Floors and Roofs: Start with the best framing components in the industry: our iLevel® Trus Joist® Silent Floor® joists;
TimberStrand® LSL rim board; and TimberStrand® LSL, Microllam® LVL, and Parallam® PSL, headers and beams. Pull
them all together with our durable iLevel® roof sheathing and self-gapping Edge® or Edge Gold® floor panels.
Walls: Get the best value out of your framing package—use TimberStrand® LSL studs for tall walls, kitchens,
and bathrooms, and our traditional, solid-sawn lumber everywhere else. Cut down installation time by using
TimberStrand® LSL headers for doors and windows, and our iLevel® wall sheathing with its handy two-way nail lines.
Software Solutions: If you are a design professional or lumber dealer, iLevel offers a full array of software packages
to help you specify individual framing members, create cut lists, manage inventories—even help you design
whole-house framing solutions. Contact your iLevel representative to find out how to get the software you need.
Technical Support: Need technical help? iLevel has one of the largest networks of engineers and sales
representatives in the business. Call us for help, and a skilled member from our team of experts will contact you
within one business day to evaluate and help solve your structural frame problems—GUARANTEED.
CONTACT US
OUR GUARANTEE
1.888.iLevel8 (1.888.453.8358)
www.iLevel.com
[email protected]
2910 East Amity Road
Boise, ID 83716
208.364.3600
P.O. Box 8449
Boise, ID 83707-2449
January 2009
Reorder TJ-8620
This document supersedes all
previous versions. If this is more
than one year old, contact your
dealer or iLevel rep.
NW
Weyerhaeuser, iLevel®, Microllam®, Parallam®, Silent Floor®, Structurwood®, Structurwood Edge®, Structurwood Edge Gold®,
TimberStrand®, and Trus Joist® are registered trademarks of Weyerhaeuser. © 2009 by Weyerhaeuser Company.
All rights reserved. Printed in the USA.