Measurements of air flows through cracks between building components

Describes a simple device which pressurises an enclosed volume of air adjacent to individual components in the building fabric. The air flow through the crackage is measured and the interdependence of the flow rate and pressure is examined. Windows, floors, loft traps and suspended ceilings are examined. A simple relationship is found to be applicable to individual components but no universal relationship is found for a general range of components with superficially similar cracks. Measurements confirm the effectiveness of draught stripping and also show that some loose fitting loft traps can be made airtight by simple measures. Other loose fitting components with rough surface finishes (e.g. suspended ceiling tiles) may not be so easily sealed and extensive leakage may occur.