Problem: Premature deterioration.
Siding can deteriorate prematurely (Figure 1) when moisture is present in the wall assembly. Fungi destroy wood fibers and promote the corrosion of metal siding and fasteners.
Cause: Condensation resulting from air leakage / Inadequate drying potential.
- Prevent the flow of warm, humid air into the exterior wall, where it can condense on the back face of cooler siding. Install an effective, continuous air-barrier system to minimize the flow of any airborne water vapor.
Provide a vapor barrier on the warm side of the wall assembly.