ABSTRACT
In the case of non ventilated compact roofs the wind tightness of the construction is usually warranted by a windproof underlay membrane and the flow resistance of the thermal insulation, as well as sealed eave and ridge details. Because of the current construction practice of wind tight layers in Austria there are numerous small leakages in the eaves, the ridge and the underlay area. Because of this and the low density and length of the thermal insulation in common Austrian constructions the wind induced pressure differences between the eaves and loft area cause an air flow which cancels the thermal insulating effect of the rock wool partially or completely. Based on different in-situ measurements of compact pitched roof constructions in Austria a test roof was constructed to investigate the effect and to validate a simulation model. In the paper first results from air and heat flow measurements and the model validation are presented.
