Construction method provides simple steps to meeting the lateral and wind uplift load requirements of the IRC.
APA–The Engineered Wood Association outlines an efficient, cost-effective construction solution for using wood structural panels with raised-heel (or energy-heel) trusses in a new System Report, Use of Wood Structural Panels for Energy-Heel Trusses, Form SR-103.
Conventional trusses can compress insulation, diminishing its R-value and creating a cold area in the building envelope at the point where the truss meets the top wall plate. Energy-heel trusses provide sufficient space for full-depth insulation without compromising the effectiveness of the attic insulation R-value. For this reason, construction with raised-heel trusses is an increasingly popular practice.
Because the International Residential Code (IRC) requirements for attaching raised-heel trusses are complex, APA System Report SR-103 provides a pre-engineered solution to this problem: combine raised-heel trusses with wood structural panels to resist loads that act on the truss connection. The construction method outlined meets the lateral load and wind uplift load requirements of the IRC without additional cutting or blocking, and strong, stable wood structural panels are very easily joined to the building.
“For builders looking to save energy when using raised-heel trusses, it makes sense to multi-task the structural wall sheathing to close off the attic area in a way that reduces air infiltration, laterally stabilizes the trusses, and creates a better connection between the roof and wall framing,” says APA Senior Engineer Ed Keith, P.E.
Using the simple steps outlined in APA System Report SR-103, building designers can check a few parameters to see if the included prescriptive attachment schedule for raised-heel trusses will meet all of the IRC load path requirements for the top of the wall. The report also provides anchor bolt spacing requirements for the base of the wall to complete both the lateral and wind uplift load paths.
For more information about using wood structural panels with raised-heel trusses, and for a free download of APA System Report SR-103: Use of Wood Structural Panels for Energy-Heel Trusses, go to APA_PR_Energy-Heel Truss_Final.docxwww.PerformanceWalls.org. Printed copies of the report are also available from APA.
About APA-The Engineered Wood Association
Founded in 1933 and based in Tacoma, Washington, APA represents approximately 160 plywood, oriented strand board, glulam timber, wood I-joist, Rim Board and structural composite lumber mills throughout the U.S. and Canada. Its primary functions are quality auditing and testing, applied research, and market support and development. www.apawood.org
