An air tightness test is only as accurate as the preparation behind it. Missing a single unsealed pathway on the day can mean a failed result, a delayed handover and the cost of a retest – most of which comes down to working through the same checklist we use with every client before we arrive on site.
Before we arrive, please make sure you’ve sent us the specific design air permeability figure and worked through the checklist below. This will greatly increase your chances of passing first time.
Air Leakage Pathway Checklist
Check for visible leaks in the following places:
- Windows: check the seal beneath the sills and around the frames.
- Doors: check the seal around all external door surrounds (especially French doors).
- Drainage traps: check they are filled with water or sealed with tape.
- Skirting and coving: check above and below all skirting and coving, then seal where necessary.
- Meter boxes: check all external supplies are sealed appropriately.
- Light fittings: check the seal around all light fittings and switches.
- Radiators / fans / heaters: check the seal around all pipes and wires.
- Boilers: check the seal around the boiler supply and flue.
- Extractor fans: check around the edge of the extracts – only the front of the grill can be sealed.
- Cooker hoods: check the seals around all penetrations.
- Soil pipes: check the seal around all soil pipes and sink waste pipes, especially those boxed in or behind kitchen cabinets.
- Bath panels: check all pipes behind bath panels are sealed properly.
- Hot water tank: check the seal around all supply pipes.
- MVHR: check the seal around all terminals.
- Chimneys: open fireplaces must be sealed prior to our arrival.
- Air bricks: where the dwelling has air bricks, these should be sealed for the test.
- Tumble dryer extracts: check the seal around the extract.
Only the controllable air flow pathways below can be temporarily sealed during the test – all the non-controllable leakage pathways above must be permanently sealed.
Temporary Sealing
The following should be temporarily sealed during the test:
- Trickle Vents: should be closed and can be sealed.
- Extractor Fans / MVHR terminals: all extracts should be temporarily sealed (please ensure these are off before sealing).
- Cooker Hoods: should be sealed from the outside or inside.
- Chimneys Flues and Air Bricks: should be temporarily sealed.
Our engineers will do the temporary sealing for you – however, if it’s done prior to our arrival, we’re able to complete more tests per visit.
Related: How to Pass an Air Tightness Test
This checklist covers the practical, on-the-day preparation. For the fuller picture – designing, building and ventilating a property to pass first time – see our companion guide:
What’s next?
Working through this checklist before we arrive is the single biggest factor in passing first time – it’s often easier to tick through a printed version on-site, so here’s one we prepared earlier:
Residential Air Tightness Checklist Printout
If you’d like our team to talk you through your specific property before the test, we’re happy to help.
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