APA Simplified Wall Bracing Method

Simplified Wall Bracing Video: Four Steps to Code-Compliant Walls

 

 

This video from APA introduces an easier way to determine IRC-compliant wall bracing: APA’s simplified wall bracing method. The video outlines how APA’s simplified wall bracing method greatly reduces the complexity of determining whether wall bracing meets the code for many common home designs.


Simplified Wall Bracing Method

The APA Simplified Wall Bracing Method offers a simpler solution for wall bracing:

  • Saves design time and associated costs
  • Faster permitting and quicker plan review
  • Saves money on metal connectors and their installation
  • Increased design flexibility for location of window and door openings
  • Uses minimum 7/16" or thicker OSB or plywood sheathing for a strong, fully sheathed structure

This page summarizes the advantages of the APA Simplified Wall Bracing Method. A complete description of how to apply the method is provided in APA System Report SR-102, APA Simplified Wall Bracing Method Using Wood Structural Panel Continuous Sheathing, Form SR-102. APA System Reports apply research and technical evaluation to innovative design solutions, using engineered wood systems that may not be directly prescribed in the codes, but can be used as alternatives to the prescribed systems for code compliance. 

For additional information, Simplified Bracing Method Streamlines Design, Form P310, is a quick-reference brochure that provides an overview of the method, including key benefits and a comparison with traditional bracing.


Simpler Bracing, Simply Stronger

Builders don’t have to compromise on strength to meet the bracing provisions of the International Residential Code (IRC). APA’s Simplified Wall Bracing Method, an enhanced variation on the 2012 IRC simplified wall bracing provisions (Section R602.12), gives builders an affordable, streamlined approach to meeting wall bracing requirements for single-family homes.

  • Most builders are already using 7/16" OSB or 15/32" plywood for wall sheathing on exterior walls. By simply using these products and increasing the number of fasteners from 6-inch o.c. spacing to 4-inch o.c., builders are well on their way to meeting the requirements of the Simplified Bracing Method.
  • Requirements are easy to understand and apply, saving design time.
  • Code officials find this method easy to understand, saving time in permitting and field inspections.
  • The Simplified Bracing Method includes bracing units as narrow as 16 inches that can be constructed on-site with common construction components, so the costs for narrow structural segments are minimal. In fact, this bracing method goes beyond the scope of the simplified bracing provisions in the IRC, by recognizing the contribution of below minimum bracing lengths in continuously sheathed walls.
  • Walls built according to the Simplified Bracing Method requirements are stronger than code minimum construction, which means that shorter segments can be recognized for their contribution to the wall bracing system. Houses designed with shorter bracing segments allow more room for windows, doors and other special design features. In short, builders have more design flexibility.
  • A house that is fully sheathed with 7/16" or thicker wood structural panels is simply stronger. The walls can withstand more wind pressure loads, provide a solid nail base for siding and trim, and make the house a safer refuge in storms.

Simplified Bracing Vs. Traditional Bracing

Traditional wall bracing, as shown in the example, must consider many wall lines, wall line spacing, off-sets in wall lines, lengths of each wall line, and many various multipliers and bracing methods. Each wall line (1-5 and A-D in the example) must be analyzed.

With the new APA Simplified Wall Bracing Method, as illustrated at right, the builder only needs to consider four walls, a few simple calculations, and one bracing method.


4 Steps to APA Simplified Wall Bracing Design
 

Step 1

Check the design of the house to make sure that it meets the criteria for the Simplified Bracing Method. (Refer to APA System Report SR-102 for a full list of criteria. System Reports are APA publications that apply research and technical evaluation to innovative design solutions, using engineered wood systems that may not be directly prescribed in the codes, but can be used as alternatives to the prescribed systems for code compliance.)

Step 2

Draw a box around all of the exterior walls of the house (as shown in Figure 2, above), measure the front-to-back and side-to-side lengths and use the table in the System Report SR-102 to determine the amount of bracing required for each side. Use the wall height multipliers to calculate the final amount of required bracing based on the height of the wall.

Step 3

Measure the length of each wall segment that is sheathed to the full wall height, without openings. Using the tables in the System Report SR-102, determine which segments are long enough to be counted as braced wall segments and record the contributing length of the segments in each of the four walls. These simple calculations allow the designer to reach the bracing requirements while providing for more window and door areas.

Step 4

Add all of the contributing lengths of wall bracing segments in each of the four walls and compare the total of each wall to the required bracing length determined in Step 2. If the total is equal to or greater than the final required amount of wall bracing determined in Step 2, the design meets the bracing requirements of the System Report SR-102.


Larger Houses

If the house plan has walls longer than 60 feet, the APA Simplified Wall Bracing Method can still be applied by dividing the floor plan into rectangles. Refer to System Report SR-102 for recommended steps.


For More Information


APA Simplified Bracing News
 

Guide Highlights Simpler Bracing Solution

Builders don't have to compromise on strength to meet the bracing provisions of the International Residential Code (IRC). The APA Simplified Wall Bracing Method offers an affordable, flexible, streamlined approach to meeting wall bracing requirements for single-family homes. The APA method expands on the 2012 IRC simplified wall bracing provisions (IRC Section R602.12), increasing the applicability of the IRC provisions to as much as four times as many house plans, including those with multiple window and door openings on the front and rear elevations.

APA's brochure, Simplified Bracing Method Streamlines Design, Form P310, provides a summary overview of the APA Simplified Wall Bracing Method, including how to use the method in four steps, the key benefits to the method, and a comparison with a traditional approach to wall bracing. The six-page brochure is available as a free downloadable PDF or a printed copy can be purchased for $1.00.


APA Simplified Bracing Method Expanded For Increased Usability

APA has revised System Report SR-102 to further increase the applicability of the APA Simplified Wall Bracing Method.

Originally published in September 2012, System Report SR-102 details the APA Simplified Wall Bracing Method, a simplified method for bracing walls of single-family houses in areas of low wind and seismic activity, while providing more flexibility for building design and construction.

Based on a multi-year research and testing initiative carried out by APA, the APA Simplified Wall Bracing Method expands on the 2012 International Residential Code Simplified Bracing Method (IRC Section R602.12) to provide an approach to bracing that is even more valuable to builders and building officials by, in many cases, decreasing the amount of required wall bracing and the minimum length of braced wall panels. In addition, the APA Simplified Wall Bracing Method increases the applicability of the IRC simplified wall bracing provisions to as much as 4 times as many house plans, including those with multiple window and door openings on the front and rear elevations.

The recent updates to System Report SR-102 expand usability of the APA method even further, increasing applicability to basic wind speeds of up to 100 mph and to Wind Exposure Category C regions. The updated System Report SR-102 also permits partial credit for shorter wall segments in continuously sheathed walls.

“These changes were requested by builders and code officials to further increase the usability of this simple approach to wall bracing," said Tom Kositzky, APA Director of Field Services. “Builders, especially regional or national builders, need solutions that work in less than 90 mph and 100 mph wind zones, as well as with different wind exposure categories. The update brings the APA Simplified Bracing Method closer to being a universal solution for builders and designers.”

To provide greater architectural latitude, the APA Simplified Wall Bracing Method calls for continuously sheathed wood structural panel bracing with an increased, yet common, minimum sheathing thickness (7/16 inch) and a closer (4 inches o.c.) perimeter nailing schedule. This approach increases the performance of the bracing panels on the first story of a two-story structure due to the additional restraint provided by the mass and stiffness of the structure above, through strength from increased fastening, and through the use of thicker, continuous plywood or OSB sheathing.

In developing the APA Simplified Wall Bracing Method, a variety of wall assemblies were tested at the APA Research Center in Tacoma, Washington to characterize the lateral performance of walls that are continuously sheathed with 7/16-inch minimum wood structural panels fastened with a specified nailing schedule. While the APA method is not a part of the building code, it is based on the 2012 IRC and other modifications permitted by IRC Sections R301.1.3 Engineering Design and R104.11 Alternate materials, design, and methods of construction.

The updated 12-page brochure,  APA System Report: APA Simplified Wall Bracing Method Using Wood Structural Panel Continuous Sheathing, Form SR-102, is currently available as a free downloadable PDF from APA. Printed copies of the report and educational training programs on the use of the new method are also available. Contact APA for more information.


System Report SR-102 Details APA Simplified Bracing Method

APA – The Engineered Wood Association offers a System Report that details a simplified wall bracing method using continuous wood structural panel sheathing. APA System Report SR-102 provides building officials, builders and designers with an enhanced approach and the supporting technical information to brace walls of single family houses in areas of low wind and seismicity, while providing more flexibility for building design and construction.

In developing the System Report, APA’s technical staff enhanced the 2012 International Residential Code (IRC) simplified wall bracing provisions (Section R601.12) to increase their applicability to a larger percentage of home designs. To provide greater architectural latitude, APA’s Simplified Bracing Method calls for continuously sheathed wood structural panel bracing with an increased, yet common, sheathing thickness (7/16”), a larger nail (8d), and a closer (4 inches) nailing schedule.This approach increases the performance of the bracing panels on the first story of a two-story structure due to the additional restraint provided by the mass and stiffness of the structure above, through strength from increased fastening, and through the use of thicker sheathing. The improved performance that this bracing method achieves means that it can be used on a greater percentage of homes with multiple window and door openings on the front and back elevations, than is allowed with the simplified bracing method in the IRC.

"APA’s objective was to further streamline the simplified wall bracing provisions in the 2012 IRC and develop a method that would be easier for builders and designers to apply. We also recognized the need for more design flexibility in the placement of braced wall lines around window and door openings,” explained Dr. BJ Yeh, P.E., APA’s Technical Services Director.  The System Report greatly reduces the complicated wall bracing provisions in the 2012 IRC from 34 pages to 7 pages.

The recommendations in the System Report are based on a multi-year research and testing initiative carried out by the Association. A variety of wall assemblies were tested at the APA Research Center in Tacoma, Washington to characterize the lateral performance of walls that are continuously sheathed with 7/16” minimum wood structural panels fastened with slightly larger nails and a tighter nailing schedule.

The Simplified Bracing Method detailed in the System Report is for use only with continuously sheathed wood structural panel bracing, and is applicable to construction in many areas of the country. The report explains how to design for adequate bracing and includes three tables that builders and designers can easily use to compute the length of braced wall sections in each wall line.