Common Air Leakage Paths Identified During Air Tightness Testing for PAS 2035. In our experience, the more complete a development, the more likely it is to achieve a low air leakage figure. When we send out our quotations, we also forward an informative air leakage checklist to help clients prepare for their air tightness test for PAS2035. By working with customers throughout the retrofit stages, we can provide advice and guidance on the most feasible ways to avoid air leakage and attain compliance for the air tightness test for PAS2035.
The most common air leakage paths identified during air tightness Testing.
Here is a list of the most common air leakage paths identified during our air tightness and smoke leakage testing:
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- Poorly installed windows and doors which do not close tightly against frames.
- Windows and doors with missing seals.
- Damaged trickle vents to window and door frames
- The gap at the wall/skirting board junction.
- Gaps through existing floorboards to all floors.
- Perimeter and internal wall/floor junctions.
- Gaps around service penetrations (such as water and electrical) through floor and walls
- Pathways through ceiling voids into masonry cavity walls
- Pathways through eaves in cavities
- Gaps around windowsills and door reveals
- Gaps around bathroom and WC services
- Gaps around kitchen and utility services.
- Gaps between dry lining and ceilings
- Unsealed chimneys
- Gaps around electrical and IT fittings
- Gaps around ceiling loft hatches
- Ventilation penetrations through the walls, ceiling, and roof
- Poorly installed extractor fans to kitchens, utility, and bathrooms
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What happens if you fail the air tightness test?
If fail your air tightness test, don’t panic! We can undertake smoke leakage testing to identify air leakage paths in your building, as well as providing a comprehensive smoke survey report, to allow for targeted remedial sealing works by your team.
We can help you pass your air tightness test for PAS 2035
We have large amount of experience in understanding the requirements of Approved Document L and PAS 2035, along with extensive experience of carrying out thousands of successful air tightness tests on a wide range of developments across London and the UK..
Accreditations & Technical Competence for Air Testing
APT Sound Testing is a UKAS‑accredited ISO/IEC 17025 testing laboratory specialising in on‑site (field) air tightness testing for commercial and large‑scale buildings. Our accreditation demonstrates that all testing, reporting and quality processes meet the highest technical and procedural standards recognised in the UK.
We are an ATTMA Level 2 registered organisation, qualified to test Large, Complicated and High‑Rise (LCHR) buildings, as well as phased and zonal hand‑over projects. In addition, we are ATTMA EA accredited, enabling us to produce accurate and compliant envelope area calculations for complex commercial structures.
With over 20 years of specialist experience, using the latest high-power UKAS calibrated Retrotec blower door equipment, our engineers have delivered testing and consultancy on some of the UK’s most prestigious and technically challenging developments, including Battersea Power Station and the Imperial War Museum London.
Our combination of accredited competence, deep technical expertise, and long‑standing industry experience ensures that every project receives reliable, repeatable and fully compliant air tightness testing to the highest professional standard.
📞 Contact Us Today
If you want to avoid costly failures and ensure your commercial building passes its air test first time, our expert team is ready to help. Please contact Darren on 07775623464 or email us at info@aptsoundtesting.co.uk