Smoke testing for AOV smoke shafts that have failed the air test

Blower door Smoke Leakage Testing is a very powerful tool to help find air leakage paths within smoke shafts that have failed the air tightness test. Here’s a quick testing methodology on how smoke testing can help identify air leakage paths within the smoke shaft fabric to allow targeted remedial works to take place.

Advantages of smoke testing smoke shafts

there are many advantages for smoke testing smoke shafts. Smoke testing reveals the pathways of air leakage, making it easier to identify air leakage paths within the envelope of the smoke shaft.

Method: To undertake accurate smoke leakage test, the smoke shaft needs to be pressurised to approx. 50Pa. High powered (pressurised) smoke test equipment is then used to fill the smoke shaft with smoke, to locate areas of air leakage through the envelope of the smoke shaft. The advantage of smoke testing is it clearly shows the pathway of air leakage which can then be recorded with camera/video camera and the findings collated into a detailed air leakage survey report, which can then be sent to the contractor to allow for targeted remedial sealing works, which usually results in an smoke shaft air test pass.

Smoke testing negates the need for heating the shaft, which is required for Thermal Imaging, which can be more difficult to organise for building contractors. Smoke leakage testing, can also be used in conjunction with Thermal imaging for more comprehensive air leakage diagnosis.


Smoke Leakage Procedure:

  1. Shut all AOV doors, except where you will be setting up the equipment inline with our smoke shaft checklist.
  2. Set up a blower door system to pressurise the entire smoke shaft.
  3. Use a high-powered smoke machine to fill the shaft with smoke.
  4. Using a camera capture photos and video of the main air leakage paths within the fabric of the smoke shaft.
  5. Produce a detailed survey report highlighting the air leakage paths through the fabric of the smoke shaft envelope.

Benefits: the smoke testing provides a visual representation of air leakage in the AOV shaft, helping you to target the sealing of air leakage paths more effectively.

Why use APT for your smoke shaft air testing?

You can use any ATTMA level 2 company to test your smoke shaft; however, what happens in the event of air test failure?

If  the smoke shaft fails the air test, most companies simply pack up their equipment and leave the site. Not APT, we pride ourselves on offering one of the most comprehensive air leakage diagnostic services in the UK.  Using our experienced test engineers, along with the latest air leakage equipment we can help you pass the air testing to your smoke shaft and achieve smoke shaft signoff.

here how we help in the event of a air test failure we provide the following services:

  • Smoke testing with small/large mechanical smoke testers
  • Thermal Imaging with high resolution cameras
  • Clear and detailed smoke leakage survey reports
  • Experienced test engineers that highlight the main air leakage paths whilst on site


Air Pressure Testing Ltd boasts a client base from one of self-builders to the largest construction companies in the UK. We offering leading design, consultancy and compliance for every part of your project, at all stages. It’s APT’s aim to provide a friendly and professional stress-free experience.

Further guidance is available in the Colt Smoke Control in Apartments Leaflet, available as a free download from  SCA “Guidance on smoke control to common escape routes in apartment buildings”, is also available as a free download from

Also, we are one of a few companies that is both UKAS and ATTMA Level 2 accredited for undertaking air tightness testing to buildings, as well as specialising in smoke shaft air testing. If you would like more information on our smoke shaft (AOV) testing and/or you would like to download our smoke shaft checklist, please contact Darren on 07775623464 or email us at: