When Should I Air Test?

4 August 2020 Kelly Newlands

Preparing for an Air Test

Timber frame cladded barn
It’s essential that your building is well prepared for when the air tester arrives onsite. Remember that you are likely to incur abortive fees if the tester arrives and your home is not ready.
A home ready for air testing is one with a completed external envelope (i.e. ensure all windows, doors and trickle vents are closed), internals completed to decoration, second-fix plumbing and electrical works completed, all penetrations through into ducts/boxings and external walls to be suitably sealed, and all sanitary-ware traps to be filled with water.
During the time of tests, work in the dwelling must cease.

What are the Common Air Leakage Areas?

Most kitchens have skirting fitted, but few have it fitted behind kitchen units. Fitting skirting behind units may seem to be a waste – and it could make fitting the kitchen units, particularly integrated appliances, more difficult – but the airtightness of a kitchen can be dramatically increased if it is sealed from top to bottom. Sink wastes should be ‘cored’ through and sealed before units are fitted. Boiler exhausts/vents should be sealed, along with water pipes, particularly where they are fitted through the ceiling.
In line with the principles for kitchens cited above, skirting should be fitted behind baths where possible. Bath/sink and toilet wastes should be sealed along with the water supply pipes. In some instances, ‘traps’ fitted beneath baths and specifically shower trays are ‘cut’ into the floor to allow for their physical size, and to make fitting easier. The cutting away of sections of floor for this purpose causes serious air leakage and should be avoided wherever possible. Bath and shower panels should be fitted and sealed.
Other general areas
Radiator pipes should be sealed where they emerge from the floor, but more importantly, where flexible piping is used and fitted through the plasterboard behind the radiators. Proprietary fittings should be used and additionally sealed if ill-fitting. Skirting to all rooms should be sealed top and bottom, including skirting to internal walls. Trickle vents should be closed prior to the attendance of the air tester.

This includes timber and concrete beam and block suspended floors – ventilation grilles, underfloor heating systems, gaps found around the perimeter, large gaps around pipes that go through the wall etc.

Or blocks, including service pipes etc.

Windows and doors
Incorrectly fitting units that leave gaps that can be exploited by wasted air.

Or other areas that go through walls, such as services.

And reveals, such as gaps around the casements etc.

Holes or gaps between plasterboard dry linings and ceilings

Partition walls (internally)

Loft hatches/access 
Poorly sealed units that leave gaps.

Recessed lights
These are within the ceiling, and ceiling roses also have the potential to leak air.

Soil and vent pipes
ncluding flue stacks.

Extractor fans
Including cooker hoods.

Service pipes
Including waste pipes, cables etc.

Leakage through walls

Gaps between external walls and solid build floors

Kingspan Timber Solutions

Kingspan Timber Solutions

Eltisley Road

Great Gransden


SG19 3AR

01767 676400