Look out for these air leakage paths to pass air tightness testing

Pass Air Tightness Testing – Common Air Leakage Paths In Dwellings

Under Building Regulations Approved Document (AD) L1A there is a mandatory requirement for air tightness testing to be carried out on new residential dwellings (houses and flats).

Why You need to Complete Air Tightness Testing

AD L1A sets out the criteria regarding the sample of dwellings to be tested, which depends on the size of the development, and the dwelling types. In addition, AD L1A provides the air tightness performance standards which the tested dwelling/s must comply with (or in most cases significantly improve upon).

The air tightness testing is carried out towards the final stages of the development, and the results of the test are ultimately incorporated into the dwelling’s as-built SAP calculation.

Given the complexity of the requirements of AD L1A, it is not surprising that the air tightness testing can be seen as a daunting process for both inexperienced and experienced developers.

How We Can Help

At Soundtesting, we have a wealth of knowledge and understanding of the requirements of AD L1A, along with extensive experience of carrying out successful air tightness tests on a wide range of developments across the UK.

In order to achieve the required air tightness targets (and to avoid the risk of a failed test), we strongly recommend that early consideration is given to the air tightness of the dwelling/s. By working with our clients throughout both the design and construction stages, we can provide advice and guidance on the most feasible ways to avoid air leakage and achieve (and often improve upon) the required air tightness targets.

In the first instance, it is good to be aware of common air leakage paths in a dwelling. Below, we provide an overview of some of the most common air leakage paths (Figure 1):

What you need to look out for

  1. Junctions between floorboards or concrete slab with perimeter and internal walls (Figure 2)
  2. Gaps around service penetrations through the floor for example; mains electricity
  3. Poorly sealed windows and doors which do not close tightly
  4. Pathways through ceiling voids into masonry cavity walls
  5. Gaps around window sills and door reveals (Figure 3)
  6. Gaps between dry lining and ceilings
  7. Open chimneys
  8. Gaps around electrical fittings (Figure 4)
  9. Gaps around loft hatches
  10. Gaps around service penetrations through ceilings including light fittings and plumbing (Figure 5)
  11. Ventilation penetrations through the ceiling and roof
  12. Bathroom extractor fan
  13. Gaps around bathroom waste pipes
  14. Kitchen extractor fan
  15. Gaps around kitchen and utility waste pipes (Figure 6)

As the requirements of Building Regulations AD L1A of has become more stringent over the last decade, air leakage targets have increased thus decreasing the margin for error. Each of the above air leakage paths can be avoided through good design and workmanship. It is essential that trades involved in the project such as plumbers, electricians and dryliners have a good understanding of the air leakage testing process and common pitfalls which can be avoided.

At Soundtesting we are happy to provide you with general air leakage design advice and onsite guidance. Upon completion of your project we provide Nationwide UKAS and ATTMA Accredited Air leakage testing for domestic and non-domestic buildings to help you demonstrate Building Regulation Compliance.

To find out more about our air tightness testing service or if you wish to discuss your project please contact us on 0151 933 6186.

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0800 123 4567

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