Hygrothermal behaviour of compact roofs in wood frame constructions through on-site measurements

Abstract

In order to reduce the total thickness of flat roofs, compact roofs are often promoted. Having the insulation between the wooden joists, these roofs are more slender. Compact roofs are however subjected to hygrothermal risks due to internal condensation, limited drying potential or sensitivity to moisture ingress, which can affect their durability. A long-term on-site measurement on five compact roofs, exposed to real Belgian outdoor climatic conditions is performed, in order to check the robustness of the tested construction elements and the real influence of smart vapour retarders, hygroscopic insulation and the colour of the waterproofing membrane.