What Happens If My Building Fails the Air Test

What Happens If My Building Fails the Air Test

What Happens If My Building Fails the Air Test
Air Pressure Testing can offer different diagnostic tools to check for air leakage paths should your building fail the initial air tightness test. We usually use two methods of identifying air leakage paths, either the smoke puffer for smaller buildings or our large smoke machines.We use the smoke pencils identify local air leakage paths as this can quickly identify the internal air leakage paths on smaller buildings, however this can be very time consuming.

For large commercial buildings we usually use our larger smoke generators. We set our large fan systems to pressurise the whole building and leave them switched on for a short period to pressurise the building to around 50 Pa. The smoke egress is then observed as it escapes from the building and is subsequently recorded via photographs and video.
Smoke tests usually take no longer than 1 hour – even for quite large buildings, and the smoke survey results highlighting the air leakage paths offer the buildering contractor invaluable information so remedial works can then be planned and targeted in an efficient manner to achieve a successful air test at the 2nd attempt.

We also offer a Thermal imaging service to identify areas of air leakage, this technique identifies the air leakage paths as well as poorly insulated areas due to discontinuous insulation etc. A report can then be provided showing the location of anomalies and subsequent air tightness detailing to attain a successful air test.

Most large buildings usually need to achieve an airtightness target of 5 m3/(hr/m2 which is fairly easy to achieve on larger commercial buildings.  Over the last few years designers have demanded significantly better standards of airtightness in residential and commercial buildings to ensure that the occupants enjoy a satisfactory state of comfort and well-being. The major benefits of tighter airtightness standard are improved energy efficiency and therefore smaller running cost throughout the buildings lifespan.

IN our experience the main areas of air leakage are usually:

Using our considerable experience in regards to air leakage test failures and smoke testing to find air leakage paths, we have built up a good understanding as to the to the most common air leakage paths in residential and commercial buildings.

Here is a list of the most common areas that may result in air tightness test failures:

General Items

  • Large gaps left around services that penetrate through the floor e.g. soil pipes etc.
  • Gaps between floorboards.
  • Around the perimeter of the floor and walls junction – air escapes behind the dot and dab plasterboard.
  • Joists that penetrate into wall construction:
  • Masonry walls: Gaps left around joists that penetrate into the inner leaf of external walls. Air leakage from the cavity into the upper floor void leaking into the dwelling through gaps between flooring and through any penetrations in the ceilings, eg recessed lights and ceiling light roses.
  • Through electrical sockets where faceplates are missing.
  • Loft hatches not fitting properly or the seals are missing.
  • Around recessed ceiling lights.
  • Doors and windows that have poor seals that do not close tightly resulting in large air leakage paths.
  • Trickle vents are damaged or missing
  • The frames are twisted do the doors and windows are not sitting tight against the seals.
  • The door/window handles are damaged and are not closing properly.
  • Missing/broken window panes.
  • Under door & window cills at the cill/wall junction.

Kitchen Units

  • Large gaps left around services that penetrate through the wall behind the kitchen units.
  • Large Gaps around poorly fitted extractor fans and cooker hoods around the wall and the ventilation duct.
  • Large gaps around the floor/wall junction.
  • Holes not sealed around the bottom of the domestic service riser.


  • Large Gaps around bath panels
  • Large gap around penetrations under the bath
  • Gaps around the sink waste
  • Large gaps around the toilets SVP where it terminates into service boxing.
  • Gaps to the rear of the toilets – especially prevalent around wall mounted toilets.

Boiler Cupboards

  • Large gaps left around services that penetrate through the walls, floors and ceilings.
  • Large gaps around ventilation flue.
  • Large gaps around the floor/wall junction behind the boiler.
  • Holes not sealed around the bottom of the domestic service riser

Whether you need a full on-going air tightness design/consultancy service, air sealing help, or just a simple air test Air Pressure Testing have the knowledge and experience to ensure your building passes first time.

If you are unsure of the air tightness services you require, please call us on 07775 623464 or e-mail us at info@airpressuretesting.net and one of our air tightness engineers will guide you through the air testing process, ensuring that you receive the right level of advice at the right time.

Comments are closed.