Building Homes That Live Beyond Their Shelf Life

Learn why this Texas architect built his home with an innovative rainscreen product.

How long should a home last? Forty years? A century or more?

It’s a tough one to answer. The array of variables, from the quality of the build to the site location, defy easy prediction. What can be reasonably asserted is any home built to code today is a vast improvement over ones built in the 1950s, 60s, and 70s.

Consider just one aspect of modern home construction, the rainscreen. The question of water management is an issue architect W. Brian Keith AIA, AICP, LEED AP researched carefully before he built his home back in 2016. Keith is a principal and vice president of JHP, a nationally respected architecture and design firm based in Dallas.

Critical Gap
Design and detailing are key considerations for an architect. In the case of Keith’s home, a four bedroom/3.5 bath 3,250 sf contemporary-style home, creating an exterior wall system that would be free of moisture was a priority. The architect knew the rainscreen air gap – the area between the water-resistive barrier (WRB) and the back of the siding – plays a well-documented role in maintaining exterior wall dryness through continuous air exposure.

Free-flowing ventilation is especially critical with walls sheathed with OSB (oriented strand board). One respected authority, building scientist Joseph Lstiburek, has observed, “… if you use OSB, a really good cavity insulation, and a housewrap, make sure you have an air gap between the cladding and housewrap/OSB interface.”

1.5 mm Raised Spacers
Keith specified OSB as the sheathing material. To create the rainscreen gap, builders usually consider one of three options to create the interior gap:

• Furring strips
• 3D plastic mesh
• Housewrap with a compressible (wrinkled) or non-compressible raised element

After careful research, Keith opted for a water management system featuring a housewrap manufactured with 1.5 mm-raised spacers and vapor permeable (19 perm rating). “One of the aspects of this wrap that impressed me is the moisture drainage is functionally equivalent to a 3/8-inch rainscreen gap,” explains Keith. A 3/8-inch gap is considered nearly ideal.

Easy Installation
The innovative housewrap is installed with familiar means and methods – no special installation tools or training is required, an important budget consideration. The system also relies on double-sided sealing tape which makes it easy for the installation crew to create a tight bond between shingled, overlapped housewrap panels. One of the housewrap installers reports, “It’s really hard to pull a traditional 2-inch seam tape in a straight line over any real distance. If double-sided tape strays up or down a little bit, it’s not a big issue. The seal is always sturdy and uniform.”

Owner Bonus
The innovative housewrap, called TamlynWrap Drainable WRB 1.5 from Tamlyn, a family-owned building products manufacturer, checked all the boxes for Keith. As a bonus, the product’s 15-year warranty on materials and labor is “… in my experience, one of the best I’ve seen in the building materials industry,” Keith observes.

Building science continues to advance our understanding of residential construction. Proven water management applications like TamlynWrap offer architects and home builders a code-compliant way to create homes that may endure well beyond their expected life span. To learn more about how TamlynWrap helps builders solve water management issues, visit tamlyn.com.