Exterior Insulation and Finish Systems (EIFS) Use in Wood-Framed Residential Construction: Design Concepts to Avoid Common Moisture Instrusion Problems

Abstract

Abstract During our field observations and water tests of wood-framed houses in North Carolina that are clad with EIFS, we noted common features in their exterior wall construction that caused significant deterioration to the sheathing and stud wall framing. For several reasons, these problems would be less severe or absent if the houses were clad with traditional residential wall systems (i.e., wood shingles or clapboards, brick veneer, or traditional stucco). To define the design “problem” we review issues relevant to the performance of surface-sealed barrier EIFS including common sources of moisture intrusion, the potential for moisture entrapment within the wall system, i.e., the lack of drying capacity of the wall, and the moisture sensitivity of various substrates. We focus on presenting suggestions for resolving the problems and designing a functional EIF system for use on moisture-sensitive substrates such as wood-framed construction, with particular attention to structures in climates with heavy rainfall and high humidity.