Transcript
SHEARBRACE Featuring iLevel® Shear Braces for Engineered and Prescriptive Applications
www.iLevel.com 1.888.iLevel8 (1.888.453.8358)
WALL SOLUTIONS
#TJ-8620 SPECIFIER’S GUIDE
Engineered for Performance
Designed for Safety
Built for Wood Structures
Compatible with IRC Bracing Requirements
Perfect for Narrow Wall Sections
Quick and Easy Installation with Anchor Bolt Kit
Limited Product Warranty
2006 IBC/IRC Code Accepted*
*Achieved code evaluation report recognition (ICC ES ESR-2652)
for compliance with the 2006 IBC/IRC
iLevel® Shear Brace Specifier’s Guide TJ-8620 January 2009
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
WHAT IS AN iLEVEL® SHEAR BRACE?
2
iLevel® Shear Brace Descriptions 2–3Kit Descriptions 4Engineered Design General Assumptions 5Allowable Design Loads— Standard Brace 6Allowable Design Loads— Braces on Raised Floor Kits 7Portal Frame Assembly 8Portal Design Information 8Allowable Design Loads— Portal Frame 9Allowable Design Loads— Stacked Shear Braces 10 Overturning Forces 11Installation Details, Trim Zones, and Allowable Holes 12Raised Floor Details 13Portal Installation Details 14Multistory Kit Installation Details 15Anchorage Embedment Depth 16Alternate Anchorage for 12" Shear Braces 16Anchor Bolt Installation 17Anchorage Details 18–19Prescriptive Specification
Wall Bracing 20How to Prescriptively Specify Braced Panels 20Prescriptive Bracing Requirements 21Prescriptive Brace Example 21Portals 22Portal Header Sizing Table 22Prescriptive Anchorage 23Alternate Anchorage for 12" Shear Braces 23
TABLE OF CONTENTS
Available Kits (see page 4 for parts list) Anchor kits: Required for all braces except braces in second story
applications.
Raised 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.
(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 iLevel® Shear Braces
Brace(1) Width Height(2)Minimum Trimmed Height
Weight (lbs)
Portal Kit (Included
with Brace)Brace Type
iSB 12x7 12" 78" 741/2" 90 Yes PortaliSB 12x7.5 12" 851/2" 82" 95 Yes PortaliSB 12x8 12" 931/4" 89¾" 105 Yes PortaliSB 12x9 12" 1051/4" 78" 115 Standard(2)
iSB 12x10 12" 1171/4" 78" 125 Standard(2)
iSB 12x11 12" 1291/4" 78" 140 Standard(2)
iSB 12x12 12" 1411/4" 78" 150 Standard(2)
iSB 12xCustom 12" 78"–1411/4"(3) 78" Varies Standard(2)
iSB 18x7 18" 78" 741/2" 130 Yes PortaliSB 18x7.5 18" 851/2" 82" 140 Yes PortaliSB 18x8 18" 931/4" 89¾" 150 Yes PortaliSB 18x9 18" 1051/4" 78" 170 Standard(2)
iSB 18x10 18" 1171/4" 78" 185 Standard(2)
iSB 18x11 18" 1291/4" 78" 205 Standard(2)
iSB 18x12 18" 1411/4" 78" 220 Standard(2)
iSB 18xCustom 18" 78"–1411/4"(3) 78" Varies Standard(2)
iSB 18xCustom–STK 18" 931/4"–1411/4"(4) N.A.(4) Varies Stacked(5)
iSB 24x8 24" 931/4" 89¾" 200 StandardiSB 24x9 24" 1051/4" 89¾" 225 StandardiSB 24x10 24" 1171/4" 89¾" 250 StandardiSB 24x11 24" 1291/4" 89¾" 270 StandardiSB 24x12 24" 1411/4" 89¾" 295 Standard
iSB 24xCustom 24" 931/4"–1411/4"(3) 89¾" Varies StandardiSB 24xCustom–STK 24" 931/4"–1411/4"(4) N.A.(4) Varies Stacked(5)
Code Evaluation: See ICC ES ESR-2652
Brace Naming SystemiSB 18x8-STK
Stackable Nominal height (ft) Width (in.) iLevel® Shear Brace
iLevel® Shear Brace Specifier’s Guide TJ-8620 January 2009 3
iLEVEL® SHEAR BRACE DESCRIPTIONS
iSB Standard Brace Narrow wall spaces Top brace in two-story
applications Balloon framing
iSB Stackable Brace Narrow wall spaces Bottom brace in two-story
applications Multi-story installation kit
available (order seperately)
iSB Portal Brace Narrow wall spaces Garages Large windows and doors
Resists bowing, twisting, and shrinking
Easy header connections
Lower brace must be STK-designated, stackable brace
iSB Standard brace
MSK for stacked applications, includes upper holdowns
Field drillable and trimmable
Convenient access for wiring
Simple connection
Portal Shear Brace
Tall Wall Shear Brace
Stackable Shear Brace
Standard Shear Brace
Standard Shear Brace
iLevel® Shear Braces are trimmable in most
applications. See page 12 for details.
iLevel® Shear Brace Specifier’s Guide TJ-8620 January 20094
KIT DESCRIPTIONS
Anchor KitsRequired 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.
Portal KitsRequired 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.
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
Available for 12" iSB
Available for 18" iSB
Available for 24" iSB
9 1/2"–16" Brace width + 3" Yes Yes No
Second Floor Joist Depth
Available for 12" iSB
Available for 18" iSB
Available for 24" iSB
91⁄2"–16" No Yes Yes
Anchor Bolt Spacer Length(1)
Bolt Holder Diameter
Nut Thread Size
Washer Type
121⁄8" 7⁄8" 9 UNC 2" Square/Round18" 7⁄8" 9 UNC 2" Square/Round24" 1" 8 UNC 2" Round
(1) Flat anchor bolt spacers are available in 121⁄8" and 18" lengths for CMU and Epoxy Anchor applications.
Anchor Kit Naming SystemAnchor Kit 18
Brace width (in.) Kit name
MSK Naming SystemMultiStory Kit 18x91/2
Floor joist depth (in.) Brace width (in.) Kit name
RFK Naming SystemRaised Floor Kit 18x91/2
Floor joist depth (in.) Brace width (in.) Kit name
iLevel® Shear Brace Specifier’s Guide TJ-8620 January 2009 5
ENGINEERED DESIGN GENERAL ASSUMPTIONS
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.
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 R Ω Cd
1997 UBC 5.5 2.8 N.A.2000 IBC 6 3 4
2003 and 2006 IBC 6.5 3 4
AC130 cyclic testing in the lab.
1" anchor bolt holder and 11/2" wrench for 24" iSBs
7⁄8" anchor bolt holder and 15⁄16" wrench for 12" and 18" iSBs
iLevel® Shear Brace Specifier’s Guide TJ-8620 January 20096
ALLOWABLE DESIGN LOADS—STANDARD BRACE
Brace(2) Width HeightTotal
Vertical Load (lbs)
Seismic Design Wind Design
Allowable Shear (lbs)
Drift at Allowable
Shear (in.)
Holdown Uplift
at Allowable Shear(3)
(lbs)
Allowable Shear (lbs)
Drift at Allowable
Shear (in.)
Holdown Uplift
at Allowable Shear(3)
(lbs)
iSB 12x8 12" 931/4" 4,500 905 0.38 8,440 995 0.52 9,280iSB 12x9 12" 1051/4" 4,500 790 0.43 8,315 890 0.59 9,370iSB 12x10 12" 1171/4" 4,500 605 0.49 7,095 665 0.54 7,795iSB 12x11 12" 1291/4" 4,500 545 0.54 7,045 600 0.60 7,755iSB 12x12 12" 1411/4" 4,500 485 0.59 6,850 535 0.65 7,555iSB 18x8 18" 931/4" 8,000 2,215 0.37 12,910 2,435 0.44 14,200iSB 18x9 18" 1051/4" 8,000 1,905 0.43 12,530 2,090 0.51 13,750iSB 18x10 18" 1171/4" 8,000 1,725 0.48 12,640 1,895 0.57 13,905iSB 18x11 18" 1291/4" 8,000 1,530 0.53 12,360 1,685 0.64 13,600iSB 18x12 18" 1411/4" 8,000 1,340 0.59 11,830 1,475 0.70 13,015iSB 24x8 24" 931/4" 8,000 4,435 0.37 18,800 4,880 0.42 20,685iSB 24x9 24" 1051/4" 8,000 3,905 0.42 18,680 4,295 0.47 20,550iSB 24x10 24" 1171/4" 8,000 3,325 0.47 17,720 3,660 0.53 19,505iSB 24x11 24" 1291/4" 8,000 3,010 0.52 17,685 3,315 0.59 19,475iSB 24x12 24" 1411/4" 8,000 2,695 0.57 17,305 2,965 0.64 19,035
Allowable Design Loads(1) —Standard Brace on Concrete Foundation
(1) Interpolation of design values is allowed for custom height braces. For braces less than 931/4" tall, use the values for a 931/4" tall brace.(2) 12" wide braces, 1051/4" 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 Out-of-Plane Lateral Loads table is based on:
– Braces used in a standard 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".
Out-of-plane lateral loads consider the total vertical load.
(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
Allowable Out-of-Plane Lateral Loads (PSF)Brace Width
Standard Brace Height8' 9' 10' 11' 12'
Attached to Double Top
Plate(1)
12" 305 210 150 110 8518" 300 210 150 110 8524" 300 210 150 110 85
Attached to Header(1)(2)(3)
12" 230 205 150 110 8518" 155 135 125 110 8524" 115 105 95 85 75
V2
V1
U C
Vertical Load
h2
h1
Vbase =OM OM =
256,050in.-lb
16,003 lbs
U C
V2 =600 lbs
V1 =1,200 lbs
Vbase =1,800 lbs
iSB 18x9 STKShear Brace
iSB 18x8Shear Brace
h2 =216.25"
h1 =105.25"
Vertical Loads (lbs)
Allowable Shear Loads (lbs)
Front View
Vertical Loads (lbs)
Out-of-Plane Lateral Loads
(psf)
Side 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 1411/4". – 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.
iLevel® Shear Brace Specifier’s Guide TJ-8620 January 2009 7
Front View
V2
V1
U C
Vertical Load
h2
h1
Vbase =OM OM =
256,050in.-lb
16,003 lbs
U C
V2 =600 lbs
V1 =1,200 lbs
Vbase =1,800 lbs
iSB 18x9 STKShear Brace
iSB 18x8Shear Brace
h2 =216.25"
h1 =105.25"
Side View
ALLOWABLE DESIGN LOADS—BRACES ON RAISED FLOOR KITS (RFK)
Brace(2) Width HeightTotal
Vertical Load (lbs)
Seismic Design Wind Design
Allowable Shear (lbs)
Drift at Allowable
Shear (in.)
Holdown Uplift
at Allowable Shear(3)
(lbs)
Allowable Shear (lbs)
Drift at Allowable
Shear (in.)
Holdown Uplift
at Allowable Shear(3)
(lbs)
iSB 12x8 12" 931⁄4" 4,500 815 0.47 7,600 895 0.61 8,360iSB 12x9 12" 1051⁄4" 4,500 690 0.52 7,265 760 0.66 7,990iSB 18x8 18" 931⁄4" 8,000 2,025 0.45 11,800 2,225 0.56 12,985iSB 18x9 18" 1051⁄4" 8,000 1,670 0.51 10,985 1,840 0.63 12,085iSB 18x10 18" 1171⁄4" 8,000 1,475 0.57 10,810 1,620 0.70 11,890iSB 18x11 18" 1291⁄4" 8,000 1,170 0.62 9,480 1,290 0.76 10,425iSB 18x12 18" 1411⁄4" 8,000 890 0.68 7,930 985 0.83 8,725
Allowable Design Loads(1) —Standard Brace on Raised Floor Kit
(1) Interpolation of design values is allowed for custom height braces. For braces less than 931/4" tall, use the values for a 931/4" tall brace.(2) 12" wide braces, 1051/4" 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 Out-of-Plane Lateral Loads table is based on:
– Braces used in a raised 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.
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 1411/4" (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.
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 ¾" 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.
RFKs are for use only in single-story, non-portal applications.
(1) Based on 160% load duration. No further increases for duration of load are permitted.
Allowable Out-of-Plane Lateral Loads(1) (PSF)Brace Width
Standard Brace Height8' 9' 10' 11' 12'
Attached to Double Top Plate
12" 305 210 150 110 8518" 300 210 150 110 85
Vertical Loads (lbs)
Allowable Shear Loads (lbs)
Vertical Loads (lbs)
Out-of-Plane Lateral Loads
(psf)
iLevel® Shear Brace Specifier’s Guide TJ-8620 January 20098
PORTAL FRAME ASSEMBLY
Pre-cut hole for light fixture
Portal straps 1/2" from edges on both sides of the brace (4 straps total per brace)
Pre-cut wiring chase
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)
Beam clear span,
8' to 18'-6"
Double Portal
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 ForcesA 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.
PORTAL DESIGN INFORMATION
Using Shear Braces in Portal Frame AssembliesThe 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 931/4" 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.
Pre-cut hole for light fixture
Use one strap on each side with a minimum uplift capacity of 500 lbs per strap
Column base with a minimum uplift
capacity of 1,000 lbsPre-cut wiring chase
Concrete design is the responsibility of the design professional
of record
Beam clear span,
8' to 18'-6"
Portal straps 1/2" from edges on both sides of the brace (4 straps total per brace)
Single Portal
iLevel® Shear Brace Specifier’s Guide TJ-8620 January 2009 9
Vertical Loads (lbs)
Out-of-Plane Lateral Loads
(psf)
Side View
ALLOWABLE DESIGN LOADS—PORTAL FRAME
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.
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.
Allowable Design Loads(1)—Portal on Concrete Foundation
(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, 1051/4" 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".
Portal Brace(2) Assembly Width Height
Total Vertical Load per
Brace (lbs)
Seismic Design Wind Design
Allowable Shear (lbs)
Drift at Allowable
Shear (in.)
Holdown Uplift
at Allowable Shear(3)
(lbs)
Allowable Shear (lbs)
Drift at Allowable
Shear (in.)
Holdown Uplift
at Allowable Shear(3)
(lbs)
Doub
le
iSB 12x7 12" 78" 8,000 2,730 0.29 8,520 3,000 0.31 9,370iSB 12x7.5 12" 851/2" 8,000 2,520 0.32 8,620 2,770 0.35 9,480iSB 12x8 12" 931/4" 8,000 2,310 0.35 8,620 2,540 0.39 9,480iSB 18x7 18" 78" 8,000 5,600 0.30 12,285 6,160 0.33 13,515
iSB 18x7.5 18" 851/2" 8,000 5,380 0.34 12,925 5,910 0.37 14,220iSB 18x8 18" 931/4" 8,000 5,150 0.37 13,510 5,665 0.40 14,860
Sing
le
iSB 12x7 12" 78" 8,000 1,300 0.27 8,115 1,430 0.33 8,925iSB 12x7.5 12" 851/2" 8,000 1,200 0.31 8,220 1,320 0.38 9,040iSB 12x8 12" 931/4" 8,000 1,100 0.35 8,210 1,210 0.42 9,030iSB 18x7 18" 78" 8,000 2,800 0.31 12,285 3,080 0.36 13,515
iSB 18x7.5 18" 851/2" 8,000 2,625 0.33 12,625 2,885 0.40 13,890iSB 18x8 18" 931/4" 8,000 2,450 0.36 12,855 2,695 0.43 14,140
Allowable Out-of-Plane Lateral Loads(1)(2)(3) (PSF)
Brace Width
Portal Brace Height7' 7.5' 8'
Attached to Header
12" 275 255 23018" 185 170 155
General Notes Allowable Out-of-Plane Lateral Loads table is based on:
– Braces used in a portal 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.
(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
Front View
V2
V1
U C
Vertical Load
h2
h1
Vbase =OM OM =
256,050in.-lb
16,003 lbs
U C
V2 =600 lbs
V1 =1,200 lbs
Vbase =1,800 lbs
iSB 18x9 STKShear Brace
iSB 18x8Shear Brace
h2 =216.25"
h1 =105.25"
Vertical Loads (lbs)
Allowable Shear Loads (lbs)
iLevel® Shear Brace Specifier’s Guide TJ-8620 January 200910
Allowable Design Loads(1) for Standard Brace in 2nd Floor, Stacked Application
Brace Width HeightTotal
Vertical Load (lbs)
Seismic Design Wind Design
Allowable Shear(2)
(lbs)
Drift at Allowable
Shear (in.)
Allowable Shear(2)
(lbs)
Drift at Allowable
Shear (in.)
iSB 18x8 18" 931⁄4" 2,000 1,235 0.43 1,420 0.47iSB 18x9 18" 1051⁄4" 2,000 1,120 0.48 1,285 0.53iSB 18x10 18" 1171⁄4" 2,000 1,000 0.54 1,150 0.59iSB 24x8 24" 931⁄4" 2,000 1,855 0.33 1,855 0.33iSB 24x9 24" 1051⁄4" 2,000 1,770 0.35 1,770 0.35iSB 24x10 24" 1171⁄4" 2,000 1,690 0.39 1,690 0.39
Allowable Reactions at Footing for Stacked Brace Applications
Brace Width
Design Category
Maximum Total Uplift
(lbs)
Maximum Base Overturning Moment
(in.-lbs)
18"Wind 23,040 368,640
Seismic 19,790 316,640
24"Wind 23,040 506,880
Seismic 21,450 471,900
Allowable Design Loads(1) for STK Brace in 1st Floor, Stacked Application
STK Brace Width HeightTotal
Vertical Load(2) (lbs)
Seismic Design Wind Design
Allowable Shear(3)
(lbs)
Allowable Shear (lbs)
iSB 18x8-STK 18" 931⁄4" 4,000 2,215 2,435iSB 18x9-STK 18" 1051⁄4" 4,000 1,905 2,090iSB 18x10-STK 18" 1171⁄4" 4,000 1,725 1,895iSB 18x11-STK 18" 1291⁄4" 4,000 1,530 1,685iSB 18x12-STK 18" 1411⁄4" 4,000 1,340 1,475iSB 24x8-STK 24" 931⁄4" 4,000 4,435 4,880iSB 24x9-STK 24" 1051⁄4" 4,000 3,905 4,295iSB 24x10-STK 24" 1171⁄4" 4,000 3,325 3,660iSB 24x11-STK 24" 1291⁄4" 4,000 3,010 3,315iSB 24x12-STK 24" 1411⁄4" 4,000 2,695 2,965
(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 931/4" required. First floor braces in stacked applications may NOT be trimmed.
General Notes 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.
ALLOWABLE DESIGN LOADS—STACKED SHEAR BRACES
(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 931/4" required.
Shear capacities shown are for individual braces only. To resist forces at both upper and lower floors in a two-story application, 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
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
Δ = (3V1h3 + 2Vbase h1)h12 K
V2
Vbase
h3
h1
h2V1
iLevel® Shear Brace Specifier’s Guide TJ-8620 January 2009 11
V2
V1
U C
Vertical Load
h2
h1
Vbase =OM OM =
256,050in.-lb
16,003 lbs
U C
V2 =600 lbs
V1 =1,200 lbs
Vbase =1,800 lbs
iSB 18x9 STKShear Brace
iSB 18x8Shear Brace
h2 =216.25"
h1 =105.25"
OVERTURNING FORCES
Given
Uncracked concrete
SDC B; Wind Speed = 100 mph (wind controls)
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" + ¾" + 2 (11/2") = 17¾"
Solution
1 From the Allowable Reactions at Footing for Stacked Brace Applications table on page 10, the maximum base overturning moment (OMmax) is: 368,640 in.-lb.
2 Compare 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.
3 Calculate 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.
4 Compare 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.
Figure 1 Elevation of stacked braces, and the structural forces
developed during lateral events.
Designing for Overturning ForcesWhen specifying stacked shear brace applications, it is important to consider overturning forces. Analysis should be performed by following these steps:
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.
3. Calculate the system’s overturning moment and shear.
4. Compare the required forces to the iLevel® Shear Brace capacity.
Calculating the Overturning Resistance of a Stacked Shear BraceThe 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.
Vbase . . . . . . . . shear at footing
V1 . . . . . . . . . shear at the top of the first floor brace
V2 . . . . . . . . . shear at the top of the second floor brace
h1 . . . . . . . . . height to top of the first floor brace
h2 . . . . . . . . . height to top of the second floor brace
w . . . . . . . . . width of brace
OM . . . . . . . . . base overturning moment
U . . . . . . . . . uplift (tension in brace anchorage)
C . . . . . . . . . compression (compression in brace anchorage)
Design Example
V2
V1
U C
Vertical Load
h2
h1
Vbase =OM OM =
256,050in.-lb
16,003 lbs
U C
V2 =600 lbs
V1 =1,200 lbs
Vbase =1,800 lbs
iSB 18x9 STKShear Brace
iSB 18x8Shear Brace
h2 =216.25"
h1 =105.25"
iLevel® Shear Brace Specifier’s Guide TJ-8620 January 200912
INSTALLATION DETAILS, TRIM zONES, AND ALLOWABLE HOLES
Standard iLevel® Shear Brace Installation Allowable Small Holes
Allowable Large Holes for Standard and STK iSBs (in addition to allowed small holes above)
Verify brace is plumb
For trim zones, see
below
Two top plates or as specified
Threaded rod
Anchor bolt spacer
Ensure concrete is level and smooth beneath brace. Grind and fill as necessary.
Foundation system design is the responsibility of the design professional of record
Hardened nut
Washer
Holdown
SB1
SB2
SB11
Optional OSB shim, 7⁄8" maximum
Optional OSB shim, 7⁄8" maximum
OPTION B 6¾" lag screws, provided, installed from the top: 6 with 12" brace 8 with 18" brace 12 with 24" brace
Optional OSB shim, 7⁄8" maximum
Do not install screws in electrical chase
OPTION A 6¾" 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)
Optional OSB shim, 7⁄8" max.
Start screws 31/2" (±1/2") from bottom of double top plate or header
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.
31/2" (±1/2")
Do not install screws in
electrical chase from either side
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 931/4" may be trimmed down to a minimum height of 741/2".
24" braces may be trimmed down to a minimum height of 89¾".
No holes allowed in top 8"
Minimum 12" above existing hole
FACE DRILL ZONE Center of brace face as shown
No holes allowed in top 8"
No holes allowed in lower 40" of brace
HOLES Maximum three
holes in face and three in edge
¾" diameter holes, maximum
6" o.c. minimum
HOLES 45⁄8" diameter
holes, maximum Maximum two 45⁄8"
holes or one 41/4" x 12" hole
No minimum on-center spacing required
EDGE DRILL ZONE Middle 1⁄3 of brace
thickness
FACE DRILL ZONE Maintain 11/2" min. edge distance from chase and outside edge, typical
For trim zones, see
below
Install nut finger-tight plus 1/8 turn, min.
iLevel® Shear Brace Specifier’s Guide TJ-8620 January 2009 13
RAISED FLOOR DETAILS
General Notes DO NOT modify the Raised Floor Kit. For floor assemblies of non-standard heights
(such as floor sheathing thicker than ¾", 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.
RFK Interior ViewRFK Installation
Bottom shear-transfer plate (pre-attached)
31/2" TimberStrand® LSL RFK block (face grooved side to exterior of building)
7⁄8" ported coupler nut
7⁄8" diameter threaded rod
Top shear-transfer plate (pre-attached)
Steel shim
Raised Floor Kit
SB7
SB8
In-line Shear Brace
SB9
❶ Thread the ported coupler nuts and threaded rods onto anchor bolts
❷ Lower block onto threaded rods and swing bottom of block and spacer plates into place
❸ Install iLevel® Shear Brace on block
Attach USP MP4F framing anchor with 0.148" x 11/2" nails. Fill all nail holes.
Foundation system design is the responsibility of the design professional of record
Sill plate
TJI® joistRFK block
Joist hanger
Ledger
Notch floor sheathing around brace
Sill plate
TJI® joist
Joist hangerLedger
Not applicable for 24" shear braces
Not applicable for 24" shear braces
11/4" TimberStrand® LSL or iLevel® 11/8" rim board
Foundation system design is the responsibility of the design professional of record
Sill plate anchor bolt (per code)
Sill plate anchor bolt (per code)
Foundation system design is the responsibility of the design professional of record
11/4" TimberStrand® LSL or iLevel® 11/8" rim board
iLevel® Shear Brace sized to include the floor system height and installed directly on the foundation
11/2" minimum clearance required on each side of the anchor bolt spacer to accommodate the RFK
11/2"
iLevel® Shear Brace Specifier’s Guide TJ-8620 January 200914
PORTAL INSTALLATION DETAILS
Portal Frame Shear Brace
Portal Frame Shear Brace with 51⁄4" or 51⁄2" Wide Header(Similar for 31⁄8" header)
Portal Frame Column
Header as specified. For 51/4" or 51/2" header, use furring as required. See detail SB5 below.
Use a strap on each side with a minimum uplift capacity of 500 lbs per strap
TimberStrand® LSL portal column or solid sawn column (3" x 31/2" minimum) per the design professional of record (trim as required)
Column base with a minimum uplift capacity of 1,000 lbs
Foundation system design is the responsibility of the design professional of record
SB3 SB4
SB5
91/4"–18" deep header as specified. Center over brace width.
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
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.
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)
31/2" wide x 91/4"–18" deep header as specified. See SB5 for other header widths and allowable furring.
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
Threaded rod
Anchor bolt spacer
Ensure concrete is level and smooth beneath brace. Grind and fill as necessary.
Hardened nut
Washer
Holdown
Foundation system design is the responsibility of the design professional of record
Optional OSB shim, 7⁄8" maximum
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.
6¾" 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)
Optional OSB shim, 7⁄8" max.
Start screws 31/2" (±1/2") from bottom of double top plate or header
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 instal-lation template is available from your iLevel representative.
Do not install screws in electrical chase
from either side
31/2" (±1/2")
Verify brace is plumb
Install nut finger-tight plus 1/8 turn, min.
iLevel® Shear Brace Specifier’s Guide TJ-8620 January 2009 15
➒ Use three USP MP4F framing anchors. Fill all holes with 0.148" x 11/2" nails.
➑ Install T-plate with 0.148" x 11/2" nails. Fill all nail holes.
11⁄8" max. floor sheathing thickness
MULTISTORY KIT INSTALLATION DETAILS
SB 10
Stackable Brace Assembly
Outside View of Connection
Not applicable for 12" shear braces
❷ 7⁄8" diameter threaded rod (1" dia. with 24" brace). Drill holes through double top plate for rods. Make holes ¹⁄8" larger than threaded rod.
❸ Cut 31/2" x 31/2" notches in floor-ing. Notching rim board on the inside may be required to accommodate rods.
➍ Hand tighten rod until 1¾"–2¾" remains above the sheathing
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
Welded nut pre-installed on multistory holdowns
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.
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
14" or 20"
➐ Install 2 layers of full-depth-and-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
Rimboard Detail
Blocking under entire width of brace
Use rim as blocking
Notching rim may be required for nut, depending on floor thickness
Notching rim may be required for threaded rod, depending on rim thickness
Locate splice as required
Threaded rod
Threaded rod diameter
+ 1⁄8"
iLevel® Shear Brace Specifier’s Guide TJ-8620 January 200916
13⁄4" (min.)
21⁄8"
Stem wallper code
Stem wall length121⁄8" min.
Anchor boltspacer
Footing
C2
C1
C3 C3
C2
Footingwidth per code
C1
13⁄4" (min.)
Stem wallper codeStem wall
8" x 18" min.
#4 rebar
#4 rebar
5" min.
Footingwidth per code
Footing design by others
Anchor bolt spacer
Concretewall height
Total threaded rod assembly
length
B
B
A
A
21⁄8"
ALTERNATE ANCHORAGE FOR 12" SHEAR BRACES
ANCHORAGE EMBEDMENT DEPTHS
General Notes for Anchorage No increases for duration of load are permitted.
Appropriate for use in areas governed by IBC or IRC.
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.
Anchorage embedment is based on ACI 318 Appendix D.
Concrete assumptions: Minimum f'c of 2,500 psi; Φ = 0.85 (condition A).
For additional information, see ICC ES ESR-2652 and iLevel Shear Brace Technical Bulletin (Reorder #TB-912).
(1) Anchor bolts are ASTM A449 or ASTM A193 B7 threaded rod and are applicable for all braces and applications within this guide.(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 in the following table:
Concrete Embedment Depths and Footing Dimensions for Threaded Rod(1)(2)(3)
Application Brace Anchor Bolt Diameter
Minimum Footing Width
Embedment Depth Minimum Footing Dimensions
Wind Seismic (SCD C-E) C1 C2 C3
Uncracked Concrete
Standard or Portal Braces
iSB 12x_ 7⁄ 8" 16" 6" 7" 6" 10" 10"
iSB 18x_7⁄ 8" 16" 10" N.A. 6" 10" 10"7⁄ 8" 22" 7" 8" 9" 13" 10"
iSB 24x_1" 25" 9" N.A. 11" 14" 12"1" 28" 9" 10" 12" 16" 14"
Two-story or Stacked Braces
iSB 18x_ STK 7⁄ 8" 28" 10" 10" 12" 16" 14"
iSB 24x_ STK1" 25" 10" N.A. 11" 14" 12"1" 30" 9" 11" 13" 17" 13"
Cracked Concrete
Standard or Portal Braces
iSB 12x_ 7⁄ 8" 22" 7" 8" 9" 13" 12"iSB 18x_ 7⁄ 8" 28" 9" 9" 12" 16" 12"iSB 24x_ 1" 32" 10" 11" 14" 18" 16"
Two-story or Stacked Braces
iSB 18x_ STK 7⁄ 8" 36" 10" 13" 16" 20" 18"iSB 24x_ STK 1" 35" 10" 12" 16" 19" 16"
Anchor Bolt Diameter Wind Seismic
(SCD C-E)7⁄ 8" 15,200 lbs 11,400 lbs1" 19,900 lbs 14,900 lbs
13⁄4" (min.)
21⁄8"
Stem wallper code
Stem wall length121⁄8" min.
Anchor boltspacer
Footing
C2
C1
C3 C3
C2
Footingwidth per code
C1
13⁄4" (min.)
Stem wallper codeStem wall
8" x 18" min.
#4 rebar
#4 rebar
5" min.
Footingwidth per code
Footing design by others
Anchor bolt spacer
Concretewall height
Total threaded rod assembly
length
B
B
A
A
21⁄8"
Section A–A
Anchor Manufacturer Embedment Depth,
Anchor Bolt Spacer Required
STB28 USP 257⁄ 8" YesSSTB28 Simpson 257⁄ 8" YesSSTB34 Simpson 317⁄ 8" Yes
Alternate AnchorageFor 12" iLevel® Shear Braces
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. Section View of Concrete Wall and FootingSection B–B
Top View of Concrete Wall and Footing
Foundation systems are the responsibility of the design professional
of record.
C3 is measured from the end of the template.
iLevel® Shear Brace Specifier’s Guide TJ-8620 January 2009 17
ANCHOR BOLT INSTALLATION
Attachment for 4x_ Header Attachment to Center iSB Under 6x_ Header
iLevel® anchor bolt spacer
iLevel® anchor bolt holder
Threaded rod
Double nut and washer assembly
Tie threaded rod to footing reinforcement (recommended)
To install shear brace flush to the outside face of wall, align bolt holder’s vertical faces with inside face of formwork
To install shear brace centered under 51⁄2" header or beam, align bolt holder’s grooves with inside face of formwork
Total threaded rod assembly length =
33⁄8" + + concrete wall height
Anchor Bolt Installation 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.
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).
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.
Grooves
Grooves
Vertical faces
13⁄4" 23⁄4"
Vertical face
Groove
21⁄4"
11⁄4"
Anchor Bolt HolderThreaded Rod Assembly
iLevel® Shear Brace Specifier’s Guide TJ-8620 January 200918
B
B
Brace width
2" min.
#4 rebar per code or plan
Anchor bolt spacer
C3 C3
13⁄4" min.
C2C1
Jam nut below anchor bolt spacer
Double nut and washer assembly
7⁄8" dia. (1" dia. with 24" iSB) threaded rod, grade A449 or A193 B7
Footing width
21⁄8"
11 ⁄4" top of washer to bottom of rod
3" min.coverage
, top of footing to top of washer
, top of footing to top of washer
Concrete wall height per code or plan (not part of )
Concrete wall height per code or plan (not part of )
13⁄4" min.21 ⁄8"
A
A
6" curb height, typ. 6" curb height, typ.
2" (min.)
#4 rebar per code or plan3" min. coverage
3" min.coverage
Anchor bolt spacer
7⁄8" dia. (1" dia. with 24" iSB) threaded rod, grade A449 or A193 B7
Double nut and washer assembly
C3Brace widthC3 C1
Footing widthC2
Jam nut below anchor bolt spacer
Stem wall per code
11⁄4" top of washer to bottom of rod
, top of footing to top of washer
, top of footing to top of washer
Concrete wall height per code or plan (not part of )
Concrete wall height per code or plan (not part of )
Portal Anchorage at Garage Curb
Concrete Foundation—Slab on Grade
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.
Section B–B
ANCHORAGE DETAILS
Foundation systems are the responsibility of the design professional
of record.
Section A–A
General Notes For C1, C2, C3, and , see tables on page 16.
C3 is measured from the end of the template.
iLevel® Shear Brace Specifier’s Guide TJ-8620 January 2009 19
ANCHORAGE DETAILS
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.
Notch bottom of shear brace (1/4" x 1" x 1") to accommodate carriage bolts.
C3 is measured from the end of the template.
Concrete Masonry Wall for Prescriptive Use Only (12" and 18" Braces Only)
2"min.
2"min.
D Footing width
D
le l
21⁄8"
3" min.coverage
11⁄4" top of washer to bottom of rod #4 rebar per code or plan
Double nut and washer assembly
Anchor bolt spacer recommended
Flat anchor bolt spacer
Ported coupler, compatible with A193 B7 threaded rod, as required
1⁄2" dia. x 5" long bolt, see details above7⁄8" dia. threaded rod, grade A449 or A193 B7
Solid grouted wall section the width of the brace plus 2", min. both sides.
Use 3,500 psi grout, min.
1⁄2" min. grout clearance
12" iSB 18" iSB
Jam nut below flat anchor bolt spacer
Jam nut below anchor bolt spacer
8" min. CMU wall with 3,500 psi min. solid grout
Flat Anchor-Bolt-Spacer Bolt Locations
5"41⁄16" 5"(Use existing holes)(Use existing holes)
, top of footing to top of washer
, top of footing to top of washer
C3 C3 C1 C2Brace width
CMU wall height per code or plan (not part of )
CMU wall height per code or plan (not part of )
Section D–D
Foundation systems are the responsibility of the design professional
of record.
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.
Section C–C
Concrete Foundation with Stem Wall or Basement
Foundation systems are the responsibility of the design professional
of record.
2" min. 13⁄4" min.
#4 rebar per code or plan Double nut and washer assembly
21⁄8"
C
C
C2
Footing widthC1
Monolithic or two-stage pour
Second anchor bolt spacer recommended for two-stage pour
Anchor bolt spacer
Ported coupler, compatible with A193 B7 threaded rod, as required
C3 C3Brace width
Stem wallper code
Jam nut below anchor bolt spacer
Jam nut below anchor bolt spacer
Concrete wall height per code or plan (not part of )
Concrete wall height per code or plan (not part of )
, top of footing to top of washer
7⁄8" dia. (1" with 24" iSB) threaded rod, grade A449 or A193 B7
3" min.coverage
11⁄4" top of washer to bottom of rod
, top of footing to top of washer
iLevel® Shear Brace Specifier’s Guide TJ-8620 January 200920
WALL BRACING
What is Wall Bracing?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.
Prescriptive wall bracing requirements are commonly satisfied in one of four ways:
1. Construct 4'-wide wall sections of code-prescribed materials.
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.
Criteria for Prescriptive DesignThe following conditions must be met in order to use prescriptive methods:
Wind speeds of less than 110 mph or less than 100 mph in hurricane regions.
Seismic design category (SDC) of A through D2.
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.
HOW TO PRESCRIPTIVELY SPECIFY BRACED PANELS
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".
– 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.
Procedure
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
iLevel® Shear Brace Specifier’s Guide TJ-8620 January 2009 21
PRESCRIPTIVE BRACING REQUIREMENTS
PRESCRIPTIVE BRACE EXAMPLE
32'-0"
17'-6"1'-9"1'-9" 1'-9"
8'-6"
32'-0"
17'-6"1'-9"2'-6" 2'-6"
8'-6"
44'-4"
6'3'
9'4'
5'3'3' 2'2'2'2'8" 8"2'
3'
44'-4"
6'3'
9'4'
5'3'3' 2'2'2'2'8" 8"2'
3'
44'-4"
6'3'
9'4'
5'3'3' 2'2'2'2'8" 8"2'
3'
44'-4"
6'3'
9'4'
5'3'3' 2'2'2'2'8" 8"2'
3'
41'-10"
7'-4" 10'6' 9'4' 2'2' 1'-6"
3'
41'-10"
6' 9'4' 2'2' 1'-6"
3'
7'-4" 10'
Situation I Seismic Design Category: A Wind Speed: 100 mph
1 No 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".
2 A braced wall panel is required every 25' of wall length. Find the number of panels required.
41'-10" ÷ 25' = 1.7. Rounding up, at least two panels are required.
3 Place 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.
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:
The distance between panel centers is 19'-4" 19'-4" < 25' OK The end distance for the site-built panel is 8' 8' < 12'-6" OK The end distance for the iSB is 12' 12' < 12'-6" OK
4 For 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
The braced panel layout is complete.
Situation II Seismic Design Category: Do Wind Speed: 90 mph
1, 2, and 3 same as Situation I.
4 However, 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'.
5 For 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!
6 Determine 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 There 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.
Given
First story of a two story house.
Total exterior wall length = 41'-10".
Determine the required bracing for the wall line shown:
A B C
19'
21'
55'
28'
3'
4'
2
1
3
Braced wall panels may be offset no more than 4'
from a braced wall line
Braced panel must start within 12'-6" of the end of a braced wall
line (8'-0" for SDC D)
Site-built panels must be at least 4' long
Laying Out Braced Wall Lines and Panels in a Typical House
Legend
32'-0"
17'-6"1'-9"1'-9" 1'-9"
8'-6"
32'-0"
17'-6"1'-9"2'-6" 2'-6"
8'-6"
44'-4"
6'3'
9'4'
5'3'3' 2'2'2'2'
8" 8"2'
3'
44'-4"
6'3'
9'4'
5'3'3' 2'2'2'2'8" 8"
2'
3'
44'-4"
6'3'
9'4'
5'3'3' 2'2'2'2'
8" 8"2'
3'
44'-4"
6'3'
9'4'
5'3'3' 2'2'2'2'8" 8"
2'
3'
41'-10"
7'-4" 10'6' 9'4' 2'2' 1'-6"
3'
41'-10"
6' 9'4' 2'2' 1'-6"
3'
7'-4" 10'
Opening in wall Wall Shear Brace locations 4' site-built panel
Braced wall panels must occur at least every 25' of the braced-wall line length
Braced wall lines may be spaced up to 35' apart
Braced wall lines, typical
Wall or opening
Code-accepted braced wall panel
Identifies each braced wall line
for easier tracking
iLevel® Shear Brace Specifier’s Guide TJ-8620 January 200922
PORTALS
PORTAL HEADER SIzING TABLE
Header must be single span. Do not run headers continuous over more than one portal.
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.
A minimum of 1,000 lbs of uplift capacity is required at the top and bottom of a single, portal column.
One Single and One Double Portal Three Single Portals
One Double Portal Two Single Portals
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.
8'-0" min. 18'-6" max.
Rough opening House
width
How to Use This Table1. Determine appropriate Roof Load and House Width.
2. Locate Rough Opening.
3. Select header size and material.
Roof Load (PSF) House Width
Rough Opening9'-3" 16'-3" 18'-3"
Non-Snow Area 125%
20LL + 15DL24' 31/2" x 91/4" T M P 31/2" x 14" T M P 31/2" x 14" T M P30' 31/2" x 91/4" T M P 31/2" x 14" T M P 31/2" x 14" M P36' 31/2" x 91/4" T M P 31/2" x 14" T M P 31/2" x 16" T M P
20LL + 20DL24' 31/2" x 91/4" T M P 31/2" x 14" T M P 31/2" x 14" M P30' 31/2" x 91/4" T M P 31/2" x 14" T M P 31/2" x 16" T M P36' 31/2" x 91/4" T M P 31/2" x 14" M P 31/2" x 16" M P
Snow Area 115%
25LL + 15DL24' 31/2" x 91/4" T M P 31/2" x 14" T M P 31/2" x 14" M P30' 31/2" x 91/4" T M P 31/2" x 14" T M P 31/2" x 16" T M P36' 31/2" x 91/4" T M P 31/2" x 14" M P 31/2" x 16" M P
30LL + 15DL24' 31/2" x 91/4" T M P 31/2" x 14" T M P 31/2" x 14" M P30' 31/2" x 91/4" T M P 31/2" x 14" M P 31/2" x 16" M P36' 31/2" x 91/4" T M P 31/2" x 16" T M P 5 1/4" x 14" M P
40LL + 15DL24' 31/2" x 91/4" T M P 31/2" x 14" M P 31/2" x 16" M P30' 31/2" x 91/4" T M P 31/2" x 16" M P 51/4" x 14" M P36' 31/2" x 91/4" M P 51/4" x 14" M P 51/4" x 16" T M P
Minimum Header Size Required
T 1.55E TimberStrand® LSL M 1.9E Microllam® LVL P 2.0E Parallam® PSL
Quantity SizePanels 2 iSB 12x7, 7.5, or 8
Headers 1 See table below
Quantity SizePanels 3 iSB 12x7, 7.5, or 8
Columns 1 31/2" x 31/2" x brace heightHeaders 2 See table below
Quantity SizePanels 3 iSB 12x7, 7.5, or 8
Columns 3 31/2" x 31/2" x brace heightHeaders 3 See table below
Quantity SizePanels 2 iSB 12x7, 7.5, or 8
Columns 2 31/2" x 31/2" x brace heightHeaders 2 See table below
24'-0" max.
8'-0" min. 18'-6" max.
8'-0" min. 18'-6" max.
8'-0" min. 18'-6" max.
General Notes
iLevel® Shear Brace Specifier’s Guide TJ-8620 January 2009 23
PRESCRIPTIVE ANCHORAGE
General Notes Minimum concrete f'c of 2,500 psi.
Standard holdown anchors are 7⁄8" ASTM A449 or ASTM A193-B7 threaded rod.
For 12" braces, A307-grade threaded rod may be used with the embedment lengths shown.
For 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.
C3 is measured from the end of the template.
Threaded Rod Installation 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.
Application Loading Condition
Embedment Length(1),
(in.)Minimum
Footing WidthMinimum
C1
Minimum C2
Minimum C3
Standard or Portal Brace
Wind, SDC A–B 6" 16" 6" 10" 10"SDC C–E See Concrete Embedment Depths table on page 16
Stacked Brace
Wind 10" 28" 12" 16" 12"SDC A–B 10" 28" 12" 16" 10"SDC C–E 10" 28" 12" 16" 14"
Prescriptive Embedment Depths and Footing Dimensions
(1) Measured from the top of the footing to the top of the washer.
ALTERNATE ANCHORAGE FOR 12" SHEAR BRACES
Anchor Manufacturer Embedment Depth,
Anchor Bolt Spacer Required
STB28 USP 257⁄ 8" YesSSTB28 Simpson 257⁄ 8" Yes
Alternate AnchorageFor 12" iLevel® Shear Braces
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.
13⁄4" (min.)
21⁄8"
Stem wallper code
Stem wall length121⁄8" min.
Anchor boltspacer
Footing
C2
C1
C3 C3
C2
Footingwidth per code
C1
13⁄4" (min.)
Stem wallper codeStem wall
8" x 18" min.
#4 rebar
#4 rebar
5" min.
Footingwidth per code
Footing design by others
Anchor bolt spacer
Concretewall height
Total threaded rod assembly
length
B
B
A
A
21⁄8"
13⁄4" (min.)
21⁄8"
Stem wallper code
Stem wall length121⁄8" min.
Anchor boltspacer
Footing
C2
C1
C3 C3
C2
Footingwidth per code
C1
13⁄4" (min.)
Stem wallper codeStem wall
8" x 18" min.
#4 rebar
#4 rebar
5" min.
Footingwidth per code
Footing design by others
Anchor bolt spacer
Concretewall height
Total threaded rod assembly
length
B
B
A
A
21⁄8"
Section A–A
Section View of Concrete Wall and FootingSection B–B
Top View of Concrete Wall and Footing
January 2009Reorder TJ-8620This document supersedes all previous versions. If this is more than one year old, contact your dealer or iLevel rep.NW
WALL SOLUTIONS
1.888.iLevel8 (1.888.453.8358)
www.iLevel.com iLevel@weyerhaeuser.com
2910 East Amity Road Boise, ID 83716 208.364.3600
P.O. Box 8449 Boise, ID 83707-2449
CONTACT US OUR GUARANTEE
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
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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,
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TimberStrand® LSL headers for doors and windows, and our iLevel® wall sheathing with its handy two-way nail lines.
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