Moisture Performance of Energy-Efficient and Conventional Wood-Frame Wall Assemblies in a Mixed-Humid Climate

Buildings

Samuel V. Glass¹  Vladimir Kochkin²  S. Craig Drumheller³  Lance Barta² 

[1] Building and Fire Sciences, U.S. Forest Service Forest Products Laboratory, 1 Gifford Pinchot Dr., Madison, WI 53726, USA;Applied Engineering, Home Innovation Research Labs, 400 Prince George’s Blvd., Upper Marlboro, MD 20774, USA; E-Mails:;Construction Codes and Standards, National Association of Home Builders, 1201 15th Street NW, Washington, DC 20005, USA; E-Mail:

关键词: moisture performance;    hygrothermal performance;    durability;    building envelope;    wood-frame;    vapor retarder;    continuous insulation;    hygrothermal simulation;   

DOI  :  10.3390/buildings5030759

来源: mdpi

【 摘 要 】

Long-term moisture performance is a critical consideration for design and construction of building envelopes in energy-efficient buildings, yet field measurements of moisture characteristics for highly insulated wood-frame walls in mixed-humid climates are lacking. Temperature, relative humidity, and moisture content of wood framing and oriented strand board (OSB) structural panel sheathing were measured over a period from mid-November 2011 through March 2013 in both north- and south-facing orientations in test structures near Washington, DC, USA. Wall configurations varied in exterior cladding, water-resistive barrier, level of cavity insulation, presence of exterior continuous insulation, and interior vapor retarder. The combination of high interior humidity and high vapor permeance of painted gypsum board led to significant moisture accumulation in OSB sheathing during winter in walls without a vapor retarder. In contrast, wintertime moisture accumulation was not significant with an interior kraft vapor retarder. Extruded polystyrene exterior insulation had a predictable effect on wall cavity temperature but a marginal impact on OSB moisture content in walls with vinyl siding and interior kraft vapor retarder. Hygrothermal simulations approximately captured the timing of seasonal changes in OSB moisture content, differences between north- and south-facing walls, and differences between walls with and without an interior kraft vapor retarder.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.