air tightness

Laboratory measurements have shown that when pressure differences are applied across wall and roof elements, the majority of the pressure drop takes place across the vapour barrier . Similarly , field measurements have shown that the majority of the leakage in Norwegian buildings occurs at the joints in the vapour barrier , at wall / floor joints , around penetrations of the vapour barrier and through holes in the vapour barrier . Prior to 1980, the standard vapour barrier in Norway was 0.06 mm thick polyethylene sheeting.

This paper presents results of air leakage measurements on brick walls and concrete block walls, used as outer or inner leaf of a cavity wall. The results are obtained using a pressure box on a series of test walls. The variable parameters that are examined: workmanship, pointing of the joints andplastering of the inner leaf. Out of the results can be concluded that, in general, only a plastered wall can guarantee a sufficient airtightness.

Sections include: measuring procedure air tightness of facades; evaluation of measuring air tightness in practice; infrared thermography; thermographical research in air tightness, ability to detect air tightness deficiencies with thermography; ability to quantify air leakage; architectural analysis of airtightness deficiencies; recommendations.