Prior research showed that inward moisture diffusion from absorptive claddings such as brick veneer, stucco, or manufactured stone veneer can be significant in wood-frame walls. The inward migration of moisture is greatest when the cladding is heated by the sun after being wetted by rain. The same phenomenon is likely to occur in CLT walls with these types of claddings (Fig. 1). General guidance on CLT building envelope design was published in chapter 10 of the U.S. CLT Handbook, which cautions that inward diffusion of moisture from absorptive claddings could lead to moisture accumulation in CLT based on initial computer modeling predictions. Experimental measurements are needed to provide a stronger basis for design of CLT exterior walls.
The objectives of the project are to measure moisture conditions in CLT walls with absorptive claddings under exposure to simulated rain and sun and to identify design and construction practices that minimize the risk of moisture accumulation in different U.S. climates.
