Air Tightness Testing
What is Air Tightness Testing?
An air tightness test measures the leakage rate of air through gaps, holes or cracks in the building. This leakage affects the buildings energy efficiency.
Do I need an Air Tightness test?
Air tightness tests are required before the sale of any newly constructed building regardless of the sale type. So this includes both private sales between two individuals and commercial properties.
How it Works
The pressure differential is measured across the building by using a large fan or number of fans which are installed temporally. All relevant openings into the property are temporally sealed and a range of pressure and environmental readings are taken. Then, with the fan switched on the air pressure is increased and/or reduced while tracking the pressure differential.
How Long is a Certificate Valid?
Once issued a certificate is valid until any structural changes have taken place, i.e extensions or modifications to the property.
Possible Air Leakage Areas
The areas listed below are common causes of uncontrolled air leakage, we recommend you take care in sealing these areas whilst in the process of construction;
- Intermediate Floors - Use joist hangers where possible, if built into the walls seal with a flexible sealant.
- Behind Skirting Boards - Seal between floors and walls
- Behind Coving - Seal between wall and ceiling
- Boxed in Pipes & Soil Stacks - Seal when pipes/soil stacks go out through the ceiling into the roof space
- Behind Bath Panels - Seal all services and pipe work that penetrate the envelope of the building
- Kitchen Units - Seal all services and pipe work that penetrate the envelope of the building
- All Other Services - Pipe work and services that enters the building ensure a good seal
- Badly Installed Trickle Vents - The test only allows for trickle vents to be shut and not sealed
- Windows and Doors - Ensure a good seal behind plaster board as well as decorators finishing mastic
- Recess Lights - Ensure they are fire check fittings that are fitted correctly
- Loft Hatch - Poor quality loft hatches often leak
- Any Remedial Work to Floorboards - Make sure any holes in timber floorboards are refitted correctly and sealed