Increased incidence of strong weather systems and the tragedies that follow high wind events have encouraged engineers and designers to rethink the way we build to improve wall strength. Stronger walls will keep home occupants safer during weather events and will increase the lifespan of the home. One of the problems is that the roof, wall and flooring systems are installed as separate entities. Connecting the OSB wall sheathing and the flooring system can create a continuous load path which can improve wall strength by up to 38%.
United we stand
Dan Dolan, Civil & Environmental Engineering, Washington State University: “We need to be designing structures that endure for 200 years. To do this we may need to invent new materials, new construction practices, and new tools. We need to re-think design as a complete system. Right now, we build floors independent of walls, independent of the roof. We don’t need to start from scratch; rather, we need to build upon what is already being used and functioning well.” Dolan spent many years at Virginia Tech studying improved ways in which to design wall systems and continues his work at Washington State University. One solution is to create a simpler system by connecting the OSB structural wall sheathing panels to the floor joists to create a continuous load path. A Virginia Tech University study showed that when the 10’ TallWall panels were installed vertically and extend into the floor joist area on a 9-foot wall, the wall was 38% stronger than conventionally sheathed 4×8 walls.
How it works
Taller OSB wall panels which are 4×9 and 4×10 are utilized. These longer sheathing panels are installed vertically using standard fasteners and tools, but with less time and effort as fewer panels are required (80 sheets of 4×10 covers the same square footage as 100 4x8s). Taller OSB wall sheathing panels have the added benefit of eliminating the horizontal mid-wall joints that 4x8s create. With those joints gone and all the edges falling on framing members it reduces air leakage (in some cases by up to 60 %.) See the NAHB study here. Not only do the taller OSB wall sheathing panels connect the wall systems to the floor joists, they can also eliminate gable end hinge points because taller OSB sheathing panels can extend beyond the top plates into the truss members. TallWall sheathing can also extend to the underside of the rafters in raised heel trusses and connect the roof to the walls. This results in a stronger, stiffer wall for fewer nail pops and more appealing aesthetics. Taller wall sheathing panels require no specialized installation methods and can be used in place of conventional OSB or plywood wall sheathing panels.