Vapor Barriers in Residential Construction: When Where and if to Utilize Them
Abstract
The major problem cited by independent residential builders in new housing constmction is moisture related, primarily, rot, decay, and the growth of molds and fungus. First recognized and investigated in a 1923 Forest Products Laboratory survey of dwellings, condensation and moisture related problems were witnessed in early exterior structure paint failure (U.S. Forest Service, 1949). Current building codes and property standards contribute to the problem since the methods employed are prescriptive rather than performance oriented, and the code requirements have tried to create a universal approach for construction rather than looking holistically at the wall assembly components (Trechsel, Achenbach, and Launey, 1982 and Sherwood and Moody, 1989). The purpose of the proposed project and report will be three fold: 1.) Conduct a review of the current building codes for residential construction practices (CABO, International Residential Code and American Society of Testing and Materials) and provide a discussion of the code prescribed installation methodologies and the informationiguidance that should be included; 2.) Produce a guide of best practices for proper design and detailing of vapor barriers according to the primary climatic region conditions for several common wall assemblies utilized in residential construction; and 3.) Analyze common wall assemblies and the associated dew point locations under several climatic conditions utilizing WUFI, a diffusion modeling software program that helps predicticompute relative humidity levels which when used in conjunction with the temperature enables the user to determine the dew point.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 05, 2003
- Accession Number
- ADA419415
Entities
People
- Deron L. Frailie
Organizations
- Air Force Institute of Technology