SR401 Airtightness of roof cavities (August 2018)

This report looks at a measurement procedure to estimate the airtightness of residential roof spaces. By using a dual fan approach, it is possible to distinguish between the leakage through the roof envelope and the air permeability of the ceiling.

Using this method, an effective leakage area for three residential dwellings with and without mould growth in the attic space is calculated and compared to international standards. In addition, the air permeability of common New Zealand ceilings and ceiling penetrations has been characterised in a specially designed test facility. The datasets are given in a tabular form and can be used in numerical simulations.