December 2008
Water intrusion and insufficient drainage can pose a potential threat to the durability and usability of residential construction and are an important concern to the building and
construction products industries.
This document presents some guidelines for designing and constructing a building
enclosure with a “rain screen” where “absorptive” or “reservoir” type exterior claddings
may be used over wood frame wall construction with wood-based sheathing.
Specifically, this document describes the use of a “rain screen” design approach to help
improve management of moisture in such walls. Open-frame wall construction (without
sheathing), or CMU walls with stucco coatings, are not addressed in this document.
Prepared by:
National Association of Home Builders
Mark F. Williams, FAIA Williams Building Diagnostics Inc.
15 pages