The Drying Potential and Risk for Mold Growth in Compact Wood Frame Roofs with Built-in Moisture

Built-in moisture in the insulation layer of a compact roof will generally dry out very slowly, compared to the drying rate in a ventilated roof construction. Intended or unintended leakages of outdoor air through the insulation layer may, however, speed up the drying rate. In this investigation, the drying potential of various configurations of compact wood frame roofs with a high level of built-in moisture has been investigated, through test house measurements and hygrothermal simulations. Compact wood frame roof elements has been wetted, and mold spores has been added to the elements. The hygrothermal conditions of the elements has been monitored through a period of 2 years, and the microbial conditions has also been registered. The possible drying effect of outdoor air leaking through the insulation layer from one side of the roof to the other has been investigated.