guest editorial

Safe From the Ground Up
Simple techniques to help homes withstand what Mother nature dishes out.

There is a site-built solution to building homes to withstand the rigors of high winds and even earthquakes that is simple and cost effective. What’s more, it requires no special components or connections.

Most residential builders are familiar with the need to use corner bracing and have been constructing narrow wall bracing segments next to door and window openings for years. What many builders do not realize is that the International Building Code (IBC) requires those bracing segments to be at least 24 inches wide. In some cases, the code requires a full 48 inches in width. This creates a challenge in locations such as garage door openings, where the design calls for more narrow wall segments adjacent to the opening.

Wall bracing is important because it helps keep walls square when the structure encounters high winds from tornadoes, tropical storms and hurricanes or earthquakes. While builders find the IBC requirements limiting, there is an easy, cost-effective solution that provides builders and homeowners with the necessary lateral strength and other benefits.

By fully sheathing the home—that is, by continuously sheathing the exterior of the structure with plywood or oriented strand board (OSB)—and by incorporating the APA (The Engineered Wood Association) Narrow Wall Bracing Method, builders can actually reduce the width of narrow wall segments to as little as 16 inches. This low-cost, straightforward framing method is simple to incorporate and gives builders an equivalent to what the codes require.

TWO COMPONENTS
APA has conducted full-scale structural tests of the narrow wall bracing method at its state-of-the-art research laboratory. The APA bracing design demonstrated equivalent strength and stiffness when compared to the prescribed braced wall units currently permitted by codes.

There are two primary components to the narrow wall bracing method:

1. Fully sheath the exterior walls with structural wood panels. A fully sheathed home provides superior structural performance over homes sheathed with non-structural products.

2. Install a header that extends beyond the garage opening to the corner framing. Once lapped by wall sheathing, the header forms a semi-movement-resisting frame. This configuration, sometimes referred to as a portal frame, provides additional resistance to wind and earthquake forces. It enables the wall leg of the frame to be narrower than otherwise required and still transfer the shear load of conventional corner bracing prescribed in codes.

ADVANTAGES OF A FULLY-SHEATHED HOME
The Narrow Wall Bracing Method and the continuously sheathed method in the IRC solve the problem of meeting code with braced walls at garage door opening. Plus, with OSB or plywood sheathing all around the house, the builder achieves a stronger home with numerous value-added features:

• Helps builders cost-effectively be equivalent to code requirements for wall bracing even while using narrow walls.

• Allows for more design flexibility around openings. Builders and designers can accommodate more window and door openings while continuing to meet or exceed the demands for wall bracing required by the building code.

• Structural wood panels add shear and racking strength that help tie the building together to resist Mother Nature’s forces.

• Adds stiffness and reduces flexing that can cause nail pops and cracks in the drywall, thus reducing callbacks.

• Helps prevent racking caused by high winds or earthquake forces.

• Helps protect the structure against airborne debris in high winds.

• Provides security and a deterrent to burglars who have been known to cut or kick through other lightweight wall sheathing materials.

• Provides an excellent noise barrier when used in combination with insulated wood-framed walls and exterior siding products.

• Provides a solid nail base and continuous coverage between framing elements for common siding products which results in a smooth, even appearance of the finished siding.