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Strong-Wall® Bracing Selector: Tutorial: Design Example

The Strong-Wall Bracing Selector (SWBS) provides pre-engineered Strong-Wall alternatives to code-prescribed braced wall panels. Strong-Wall model numbers and foundation anchorage designs are determined to meet job specific requirements and provide the narrowest bracing solutions possible. This app can be used with the Wall-Bracing-Length Calculator: Start with the WBLC to determine wall bracing length requirements then export project information and bracing requirements to the SWBS.

Table of Contents

Overview

The Strong-Wall Bracing Selector provides equivalent wall-bracing solutions based on the wall-bracing requirements of the International Residential Code® (IRC) and the Conventional Light-Frame Construction Section 2308 of the International Building Code® (IBC). The required total length of bracing, as well as panel spacing, wall height limits, structure weight limits, and etc. shall be based on the governing code used for design. Code references in this tool refer to the 2015 IRC unless specific reference is made to the 2012 IRC or 2009 IRC. While the IRC edition used may affect the required bracing, it does not affect the Strong-Wall bracing substitutions. The wind and seismic wall-bracing solutions in this tool may be considered equivalent to the code braced-wall-panel construction Method WSP (Wood Structural Panel) with gypsum board applied on the opposite face as defined in table R602.10.4 of the 2015 IRC. The seismic-with-masonry-veneer wall-bracing solutions are designed to be equivalent to the construction method and hold down requirements in table R602.10.6.5 of the 2015 IRC and Section 2308.6.10 of the IBC.

Strong-Wall Shearwall Information

Wood and Steel Strong-Wall shearwalls have been evaluated to the 2015 IBC/IRC in ICC-ES code report ESR-2652 (WSW) and ESR-1679 (SSW). This tool expands on the braced-wall-panel allowance in the code reports to provide specific braced-wall-panel contributing lengths and corresponding anchorage solutions for various applications and foundation types. Balloon-frame applications for tall walls up to 20 ft are designed to provide equivalent performance to a two-story braced-wall-panel application. Required length of bracing for balloon-frame applications should be based on the length required for the bottom story assuming the balloon-framed wall counts as the bracing for both stories.

Spacing between adjacent Strong-Wall shearwall panel edges may exceed 20 ft or begin more than 10 ft from the end of the braced-wall line (such as at each end of a three-car garage or at one end of a two-car garage) provided a continuous header or header splice is used as a collector along the garage front. It is recommended that a minimum of two panels be provided at garage fronts except that garage fronts up to 25 ft in length may use a minimum of one panel with a 6 ft contributing length. The total length of braced-wall-panels and contributing length of Strong-Wall panels provided shall not be less than that required for the corresponding wind speed or SDC.

Strong-Wall shearwall solutions are based on the following maximum total vertical loads acting along the length of the panel:

  • 1000 lb
    • First Story — Single Story
    • Balloon-Framing
  • 2000 lb
    • First Story — 1st of 2 or 3 Story on Wood Floor
    • Two Story stacked (1000 lb for each story)
  • 4000 lb
    • First Story — 1st of 2 or 3 Story on Concrete or CMU
    • Garage Front — Single Story
  • 7500 lb
    • Garage Front — 1st of 2 or 3 Story

Axial and out-of-plane loads for the Wood and Steel Strong-Wall shall be limited to values shown in the current Strong-Wall Shearwalls catalog.

Anchorage

Anchorage solutions provided in this selector are for anchorage of Strong-Wall shearwalls only. The foundation construction should be specified by the Designer to meet all other code requirements. As a minimum, it is recommended that when using Strong-Wall shearwalls, the foundation match the requirements for the alternate braced-wall-panel (Method ABW) in the IRC or IBC. The alternate braced-wall-panel requires a continuous foundation across the length of the braced-wall line that is reinforced with a minimum of one #4 rebar top and bottom.

Project Information

Braced-Wall Line ID

Enter the wall line identification for which bracing requirements will be considered. If using the Strong-Wall Bracing Selector in conjunction with the Wall-Bracing-Length Calculator, the pre-populated braced-wall lines from which to choose are from the same level, and only indicate parallel wall lines, i.e., side-to-side or front-to-back.

Total Length of Wall Bracing Required in Braced Wall Line

The total length of wall bracing required for the braced-wall line under consideration shall be based on the code braced-wall-panel construction Method WSP (Wood Structural Panel) with gypsum board applied on the opposite face as defined in table R602.10.4 of the 2015 IRC. .The seismic-with-masonry-veneer wall-bracing solutions are designed to be equivalent to the construction method and hold down requirements in table R602.10.6.5 of the 2015 IRC and Section 2308.6.10 of the IBC. All applicable adjustment factors in accordance with Section 602.10.3 of the 2015 and 2012 IRC or Section R602.10.1.2 of the 2009 IRC based on the bracing method above shall be applied.

Total Length of Qualifying Site-Built Wall Bracing Provided

Depending on the location and width of full-height wall segments within a braced-wall line, intermittent or continuously sheathed bracing methods described in the code and summarized in the Wall-Bracing-Length Calculator Tutorial may satisfy all or a portion of the total length of wall bracing required for a braced-wall line. The total length of qualifying site-built wall bracing represents the total length of all braced-wall-panels within the braced-wall line under consideration meeting the braced-wall-panel requirements in Section R602.10.4 of the 2015 and 2012 IRC or Sections R602.10.2 or Section R602.10.4 of the 2009 IRC.

Remaining Length of Wall Bracing Required

When the total length of wall bracing required cannot be satisfied by code bracing methods, a Strong-Wall shearwall solution may be used to satisfy the remaining length of wall bracing required as follows:

  • If the remaining length of wall bracing required is 0 ft., code wall bracing is sufficient, and no additional bracing is necessary.
  • If the remaining length of wall bracing required is less than or equal to 10 ft, the wall bracing requirement may be satisfied with a single Strong-Wall panel in most cases. The Strong-Wall Bracing Selector automatically provides a solution based on the minimum number of panels required to satisfy the wall bracing requirement. Alternatively, the user may select the desired number of panels for their solution based on wall line geometry and anchorage considerations. If a solution is not available based on user input, the user will be prompted to increase the number of panels for the solution.
  • If the remaining length of wall bracing required is greater than 10 ft, then two or more Strong-Wall shearwalls will be required to provide an equivalent wall bracing solution. The Strong-Wall Bracing Selector automatically provides a solution based on the minimum number of panels required to satisfy the wall bracing requirement. Alternatively,the user may select two or more panels for their solution based on wall line geometry and anchorage considerations. If a solution is not available based on user input, the user will be prompted to increase the number of panels for the solution.
  • If additional wall bracing is required, and there are no remaining full-height wall segments wide enough to accommodate a Strong-Wall shearwall, consider replacing site built wall bracing satisfying code requirements, or a portion thereof, with a Strong-Wall shearwall. Verify the remaining site built wall bracing still satisfies code requirements.

Strong-Wall shearwall wall bracing solutions may not be mixed with Continuously Sheathed methods in the same braced-wall line. Verify that the requirements of Section R602.10.4.1 of the 2015 and 2012 IRC or Section R602.10.1.1 of the 2009 IRC covering mixing intermittent and/or continuously sheathed bracing methods for braced-wall lines within a story or from story to story are followed.

Project Inputs

Jobsite Category

The Jobsite Category is dependent upon a number of factors including basic wind speed, seismic design category (SDC) and structure type, i.e., detached dwelling or townhouse. If coming from the Wall-Bracing-Length Calculator, this item will be automatically chosen, however if using the selector independently use this table and map to select the appropriate Jobsite Category or see the descriptions below:

  • Wind – Structure is a detached one- or two-family dwelling or townhouse in SDC A and B with or without masonry veneer; or a detached one- or two-family dwelling in SDC C with or without masonry veneer.
  • Seismic – Structure is a townhouse in SDC C with or without masonry veneer; or a detached one or two-family dwelling or townhouse in SDC D0, D1, and D2 without masonry veneer exceeding first story height.
  • Seismic with Masonry Veneer – Structure is a detached one- or two-family dwelling in SDC D0, D1, and D2 with masonry veneer exceeding first story height.

Local and/or regional building codes may have adopted specific amendments to the building code. Consult the local and/or regional building authority to ensure compliance.

Jobsite categories and their descriptions listed are for designs in accordance with the IRC. Further, the Wall-Bracing-Length Calculator may not be used in conjunction with the IBC. For designs in accordance with the Conventional Light-Frame Construction Section 2308 of the IBC, the applicable Jobsite Category may be determined by following this table.

Application

The application defines the location and type of installation of the braced-wall-panel within the structure. Strong-Wall Shearwalls may be used for first story and two-story stacked applications or in cases where balloon-framing is used such as two-story great rooms. Site built braced-wall panels must be used at the 2nd story if not using a two-story stacked Strong-Wall, and at the 3rd story.

Foundation Type

The Strong-Wall may be installed onto a rigid base such as concrete or concrete masonry units (CMU), or installed on a wood floor system depending upon the application. The foundation type defines anchorage solutions and may include slab-on-grade, brick ledge, or stemwall foundations. When a concrete stemwall foundation is used, the Strong-Wall anchorage may terminate in the wall or be required to extend into the concrete footing below depending upon the wall bracing requirements. When a CMU stemwall foundation is used, the anchorage is required to extend into the concrete footing below in all cases.

Anchorage solutions provided in this selector are for anchorage of Strong-Wall shearwalls only. The foundation construction should be specified by the Designer to meet all other code requirements. As a minimum, it is recommended that when using Strong-Wall shearwalls, the foundation match the requirements for the alternate braced-wall-panel (Method ABW) in the IRC or IBC. The alternate braced-wall-panel requires a continuous foundation across the length of the braced-wall line that is reinforced with a minimum of one #4 rebar top and bottom.

Concrete Foundation Strength

The concrete foundation strength characterized by its compressive strength (f'c) is used to determine the Strong-Wall anchorage solution. Typically, anchorage embedment depths decrease as concrete strength increases. The bearing capacity of the concrete is also related to its compressive strength and may affect the panel solution. When the Strong-Wall is installed onto a CMU stemwall, the prism design compressive strength (f'm) is assumed to be 1500 psi for bearing capacity determination.

Installations on CMU foundation walls are based on 8 in nominal grout filled CMU. CMU shall be grout filled at Strong-Wall locations minimum and fully grouted where required by code. The minimum CMU prism design compressive strength shall be f'm = 1500 psi or greater. To achieve f'm = 1500 psi, a minimum grout strength of 2000 psi using standard ASTM C90 concrete masonry units with 1900 psi minimum compressive strength and type M or S mortar is required.

1st Story Wall Height

Select the nominal wall height of the 1st story wall framing. For Garage Front Applications, 7 ft, 7.4 ft, and 8 ft Strong-Wall portal models are installed with the garage header on top of the Strong-Wall. Alternatively, standard Strong-Wall models extending to the underside of the top plates may be used at garage fronts when a full height wall is needed or desired. In general, Strong-Wall options are provided based on the nominal height of the framing to which the top of the panel will be fastened.

2nd Story Wall Height

Select the nominal wall height of the 2nd story wall framing for Two-Story Stacked applications.

Nominal Wall Height

Select the nominal wall height of the balloon-wall-framing, up to 20 ft, for Balloon-Framing applications.

1st Floor Joist Depth

This option only appears for non Garage Front Applications when the selected Foundation Type states installation onto Wood Floor. 1st floor joist depth affects the design of Steel Strong-Wall panels installed on wood floors.

2nd Floor Joist Depth

This option only appears for Two-Story Stacked Applications. 2nd floor joist depth affects the design of the upper story Steel Strong-Wall panel. The joist depth is also considered in the cumulative overturning evaluation of Two-Story Stacked Strong-Wall designs.

Strong-Wall Product Information

Number of Wall Segments to Consider

The number of wall segments to consider is dependent upon the number of available full-height wall segments wide enough to accommodate a Strong-Wall shearwall. The user shall determine the number of available segments to be filled with Strong-Wall shearwalls in order to satisfy the remaining wall bracing required for a given wall line. The user may indicate the minimum number of panels required to satisfy the bracing requirement or as an alternative, select the number of panels to satisfy the bracing requirement for a given wall line. If the number of segments selected is not sufficient to satisfy the bracing requirement for the wall line, the Strong-Wall Bracing Selector will prompt the user to increase the number of segments so that a solution is available.

Typically, it is desirable to satisfy the bracing requirement with the minimum number of Strong-Wall shearwall panels possible. There may be instances however where multiple 12 in wide panels would be preferred to a single 24 in wide panel for example. Further, the anchorage requirements are dependent upon both the width and number of Strong-Wall shearwall used to satisfy a bracing requirement. In general, anchorage requirements, i.e., footing dimensions and anchor embedment depth, are generally less for wider and/or multiple panels.

Strong-Wall Type

Select the Simpson Strong-Tie Panel type(s) that will be presented as available solutions. When the Strong-Wall Type is limited based on previous Project Input selections, this drop-down is automatically populated with the applicable wall type and disabled.

Strong-Wall Locations

Select the location(s) of the braced-wall-panel(s). Select Corner and Midwall to present braced-wall-panel options and anchorage solutions for both location options. When Garage Front Applications are chosen, the drop-down provides the option to use a Single Panel or Double Panel at the garage front. It is recommended that a minimum of two panels be provided at garage fronts except that garage fronts up to 25 ft in length may use a minimum of one panel with a 6 ft contributing length. When multiple Strong-Wall panels are used in the same braced-wall line to satisfy bracing requirements, mixing Wood and Steel Strong-Wall panels is not recommended, however using panels of different widths is acceptable.

Multi-Ply Header

This option only appears for Garage Front applications with wall heights of 7 ft, 7.4 ft, or 8 ft with Header on Top of Wall. It provides an option to select a solid or multi-ply header. If the header is solid, leave unchecked. Steel Strong-Wall panels with multi-ply headers are limited to wind designs and SDC A-C (IBC & IRC).

Portal Kit

This option only appears for Garage Front applications with wall heights of 7 ft, 7.4 ft, or 8 ft with Header on Top of Wall. When selected, the portal system typically reduces anchorage requirements.

Available Wall Segment Space

Indicate the length of the designated full-height wall segment within a braced-wall line that is not being used for code wall bracing. These are typically wall segments not wide enough to accommodate the required minimum length of braced-wall-panels defined in Tables R602.10.5 and R602.10.5.2 of the 2015 IRC and 2012 IRC and Tables R602.10.3 and R602.10.3.1 of the 2009 IRC. If no Strong-Wall solutions are available based on the length selected, code bracing may need to be replaced with a Strong-Wall enabling a longer available wall space to be selected.

General Notes

Basic Bracing Requirements

The required length of bracing shall be based on sections R602.10.3, R602.10.6.5, and the braced-wall panel-location requirements of Section R602.10.2.2. The minimum length of a braced-wall panel shall be based on Section R602.10.5. In general, the distance between adjacent edges of braced-wall-panels along a braced-wall line shall be no greater than 20 ft and begin not more than 10 ft from the end of the braced-wall line. Braced-wall-panels may be offset out-of-plane up to 4 ft from the braced-wall line with the total out-to-out offset limited to 8 ft. The minimum number of braced-wall-panels required within a braced-wall line except at garage fronts with a continuous header or header splice is detailed in Section R602.10.3. Structures located in SDC C or higher except those exempted in section R301.2.2 of the IRC are subject to the limitations for weights of materials in section R301.2.2.2.1. In general, the combined roof and ceiling dead load may not exceed 15 lb per square foot (psf) unless the required wall-bracing length is adjusted per table R301.2.2.2.1 for roof/ceiling dead load up to 25 lb psf. For designs based on the IBC, the limitations of Section 2308.2 limit the roof/ceiling dead load to 15 lb psf. There are additional braced-wall-panel location requirements for higher seismic design categories that must be considered. For more detail, see the 2015 IRC, 2012 IRC or 2009 IRC tutorials in the Wall-Bracing-Length Calculator describing bracing requirements.

Braced-wall-panel heights greater than 10 ft and up to 12 ft are allowed provided the required length of bracing is increased as required by section R301.3. For designs based on the IBC, braced-wall-panel heights shall not exceed 10 ft. Balloon-frame applications for tall walls up to 20 ft tall are designed to provide equivalent performance to a two-story braced-wall panel application and may exceed the braced-wall-panel height limits based on IRC section R301.3 or IBC Section 2308.2.

When structures or portions thereof are designed per the Conventional Light-Frame Construction Section 2308 of the IBC, bracing requirements including braced-wall line and braced-wall-panel length, spacing, and location shall be in accordance with the provisions contained therein. Typically, braced-wall line length requirements are listed as a percentage of wall length. Bracing requirements expressed as a percentage must be converted to a length in feet for use with the Strong-Wall Bracing Selector.

Strong-Wall Shearwalls — Garage Front Applications

Spacing between adjacent Strong-Wall shearwall panel edges may exceed 20 ft or begin more than 10 ft from the end of the braced-wall line (such as at each end of a three-car garage or at one end of a two-car garage) provided a continuous header or header splice is used as a collector along the garage front. It is recommended that a minimum of two panels be provided at garage fronts except that garage fronts up to 25 ft in length may use a minimum of one panel with a 6 ft contributing length. The total length of braced-wall-panels and contributing length of Strong-Wall panels provided shall not be less than that required for the corresponding wind speed or SDC.

See header support post installation requirements for Wood or Steel Strong-Wall shearwall portal installations. Multi-ply headers may be used for garage-front applications.

See multi-ply header installation requirements. Solid headers shall be used with the Steel Strong-Wall shearwall in SDC D0, D1, and D2 (SDC D and E for IBC governed designs).

When a pony-wall occurs over the garage header, sheath the entire pony-wall area from top plates to header with minimum wood structural panels and nailing per Method WSP. For method BV-WSP, sheathing and nailing shall be per R602.10.6.

Anchorage

Anchorage solutions provided in this selector are for anchorage of Strong-Wall shearwalls only. The foundation construction should be specified by the Designer to meet all other code requirements. As a minimum, it is recommended that when using Strong-Wall shearwalls, the foundation match the requirements for the alternate braced-wall-panel (Method ABW) in the IRC or IBC. The alternate braced-wall-panel requires a continuous foundation across the length of the braced-wall line that is reinforced with a minimum of one #4 rebar top and bottom.

Cast-in-place WSW-AB, PAB and SSWAB anchorage solutions are designed based on ACI 318-14 assuming uncracked concrete and no supplemental reinforcement. Anchorage solutions for seismic governed designs include a 0.75 reduction factor on breakout strength per ACI 318-14 Section 17.2.3. SB anchorage solutions are based on testing conforming to ICC-ES acceptance criteria AC 399.

Post-installed adhesive anchorage solutions are based on testing and finite element analysis (FEA) modeling into uncracked concrete with no supplemental reinforcement and a safety factor of 4.0 on ultimate loads when Wind Jobsite Category applies, and a safety factor of 5.0 on ultimate loads when Seismic Jobsite Category applies. For additional adhesive-anchor design and installation information, see the current Anchoring and Fastening Systems catalog or view the Simpson Strong-Tie Anchorage Systems.

Installations on CMU foundation walls are based on 8 in nominal grout filled CMU. CMU shall be grout filled at Strong-Wall locations minimum and fully grouted where required by code. The minimum CMU prism design compressive strength shall be f'm = 1500 psi or greater. To achieve f'm = 1500 psi, a minimum grout strength of 2000 psi using standard ASTM C90 concrete masonry units with 1900 psi minimum compressive strength and type M or S mortar is required.

For holdowns and anchor bolts, nuts should be finger-tight plus 1/3 to 1/2 turn with a hand wrench, with consideration given to possible future wood shrinkage. Care should be taken to not over-torque the nut. Impact wrenches should not be used as they may preload the anchor or holdown.

The Strong-Wall Bracing Selector does not provide a complete building design. The user of this tool is responsible for complying with IRC/IBC prescriptive provisions or consulting a professional Designer to address all other structural elements not included herein. Refer to the applicable building code for all other structural elements, connections, fastening schedules, and member designs.

Strong-Wall shearwall panels used as braced-wall-panels are part of the overall lateral-force-resisting system of the structure. This tool provides equivalent braced-wall-panel replacements and anchorage solutions only. Specification of the remainder of the building's lateral-force-resisting system, including the load path to transfer lateral forces to the Strong-Wall panels, is the responsibility of the Designer. Installation of Strong-Wall shearwalls shall be done in conformance with this tool and the current Strong-Wall Shearwalls catalog. Also refer to the Strong-Wall Shearwalls catalog for other important information including Terms and Conditions of Sale and other information. This information may also be obtained at www.strongtie.com.

Local and/or regional building codes may require meeting special conditions. For compliance with these requirements, it is necessary to contact the local and/or regional building authority. Except where mandated by code, Simpson Strong-Tie products do not require special inspection.

Simpson Strong-Tie reserves the right to change specifications, designs, and models without notice or liability for such changes.

Refer to current Wood Construction Connectors catalog for information and General Notes for Simpson Strong-Tie connectors.

IRC Map and Jobsite Category Table

For 2015 IRC designs use the table below to determine your jobsite category for use in this selector.

IRC Ultimate Design
Wind Speed
Veneer Condition SDC Structure Map Reference Color Jobsite Category
110-140 MPH With or Without Masonry Veneer A,B Detached one- and two-family dwellings and townhouses
Wind
C Detached one- and two-family dwellings
Wind
C Townhouses
Seismic
Without Masonry Veneer D0, D1, D2 Detached one- and two-family dwellings and townhouses
Seismic
With Masonry Veneer D0, D1, D2 Detached one- and two-family dwellings
Seismic with Masonry Veneer
Townhouses
Not Permitted
With or Without Masonry Veneer E Detached one- and two-family dwellings and townhouses
Not Permitted
≥ 140 MPH or where wind design required With or Without Masonry Veneer All Detached one- and two-family dwellings and townhouses
Not Permitted
  1. Regions where wind design is required are defined in figure R301.2(4)B and include portions of the U.S. Atlantic Ocean and Gulf of Mexico coasts, Hawaii, Puerto Rico, Guam, Virgin Islands and American Samoa.
  2. "Not Permitted" indicates an engineered design is required.
  3. 2012 IRC based Designs Map and Jobsite Category Table.
  4. 2009 IRC based Designs Map and Jobsite Category Table.

Local and/or regional building codes may have adopted specific amendments to the building code. For compliance with these amendments it is necessary to contact the local and/or regional building authority.

Wind and Seismic Map for IRC

The map below may be used as a general guide to determine the appropriate Strong-Wall wall bracing replacement tables to use based on the geographical location of your structure. The map is based on soil Site Class D. Contact your local Building Department for applicability in your area and to confirm wind speed, Seismic Design Category and Site Class requirements. The U.S. Geological Survey (USGS) offers an internet calculation tool to help determine the appropriate Seismic Design Category based on the project site zip code or longitude and latitude. Go to the USGS website for more information.

IBC Jobsite Category Table

For 2015 IBC Section 2308 designs use the table below to determine your jobsite category for use in this selector.

IBC Ultimate Design Veneer Condition Seismic Design Category Jobsite Category
115-130 MPH or
110-140 MPH Non-HPR
with Wind Exposure Category B2
With or Without Masonry Veneer A
Wind
Without Masonry Veneer B
Wind
C,D,E
Seismic
With Masonry Veneer B Section 2308.6.10.1, Exception 1 or 2
Wind
C Section 2308.6.10.1, Exception 2
Seismic
B,C Section 2308.6.10.1, Exception 3
Seismic with Masonry Veneer
D3
Seismic with Masonry Veneer
E Not Permitted
With or Without Masonry Veneer F Not Permitted
>130 MPH or
> 140 MPH in Non-HPR with
Wind Exposure Category B
With or Without Masonry Veneer All Not Permitted
  1. "HPR" = Hurricane-prone region, which is defined in the IBC as the U.S. Atlantic Ocean and Gulf of Mexico coasts where the ultimate design wind speed is greater than 115 mph and Hawaii, Puerto Rico, Guam, Virgin Islands, and American Samoa.
  2. The IBC permits masonry veneer in SDC D only when the provisions of Section 2308.6.10.2 are satisfied.
  3. "Not Permitted" indicates an engineered design is required.

Local and/or regional building codes may have adopted specific amendments to the building code. For compliance with these amendments it is necessary to contact the local and/or regional building authority.

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