Siding to Last a Lifetime
Rainscreen details that improve the durability of any lap-siding installation.
Synopsis: In this article, a builder and remodeler outlines siding details that prevent leaks, rot, and structural damage. He installs a rainscreen detail, or lap siding over an airspace—siding nailed to 3/4-in.-thick furring strips. Vents at the top and bottom of the wall allow any water that gets behind the siding a chance to get back out, and the air gap promotes fast drying. The author describes the layout of the siding, the installation of each course of siding, and the watertight details above and below windows (with detailed illustrations). The article includes a sidebar showcasing the author’s favorite fasteners.
My partner, Joe Filanowski, and I have been working together for almost 20 years. He handles the business side of our custom-home-building business and I run the job site. Most of our work is along the western Connecticut coastline, where homes are routinely pounded by coastal storms packing savage winds.
Through our remodeling work, we came to the conclusion long ago that even the best siding jobs leak when subject to gale-force wind and rain. We’ve seen firsthand the rot and structural damage that occurs when rain is forced behind siding and can’t get out. The stakes are even higher with modern insulation and air-sealing requirements, because there’s often very little drying potential when the inevitable leak occurs. For all these reasons, we now insist that clients install lap siding over an airspace on major remodels and new builds.
We nail the siding to 3⁄4-in.-thick furring strips, and assembly often described as a rainscreen. Vents at the top and bottom of the wall allow any water that manages to get behind the siding a chance to get back out, and the air gap eliminates pressure differentials—which can cause water to be sucked inward—while also promoting…