Occurrence of Mold in a Two-Story Wood-Frame House Operated at Design Indoor Humidity Levels

摘要

Mold growth was observed in limited areas in a two-story contemporary wood-frame house during the seventh heating season of operation at or near design indoor humidity levels. The house was in a cold climate (Madison, Wisconsin). Humidity levels were estimated as being exceeded in one of 10 homes at this location. Moderate amounts of window condensation were observed during each of the seven heating seasons. Areas of observed mold growth were limited to the lower extremities of windows (near the lower edge of glass panes) and the edges of lower panels of a wood panel entry door that was not equipped with a storm door. Mold growth was also present in sprayed-on cellulose insulation in close proximity to the rim joist (board) in the basement, although this mold was not visible unless the insulation was disturbed and was probably present during previous heating seasons. Mold from these locations was cultured, isolated, and identified morphologically or by DNA sequence.