Hygrothermal Performance of Residential Cantilevered Floors

Abstract

This field investigation was designed to compare three insulation strategies commonly used in residential cantilevered floors. The first objective is to determine floor surface temperatures above insulated cantilever cavities, with respect to occupant thermal comfort. The second objective is to determine moisture behavior within insulated cantilever cavities, with respect to durability. The experimental set-up was installed in the cantilevered floor of an existing Minnesota home. The first six months of investigation, from mid-summer into early winter, provided data for analysis and discussion presented in this thesis. Investigation results support the view that cantilevered floor cavities open to adjacent conditioned space have warmer floor surfaces above them. Condensation and wetting in some cantilever cavities during colder weather suggests that durability risks are increased in cavities where there is air movement through the thermal insulation. Further investigation is expected to provide a more comprehensive representation of the annual hygrothermal cycle.