We have a lot of builders calling us and panicking before their Air Tightness Test and asking ‘how do I make sure I pass my test?’, although we can offer them our Top Tip Checklist which in most cases is enough to pass it isn’t exactly the full answer. The truth is, making an airtight house starts from the very beginning. Every tradesman involved can help and we’re here to tell you how.
From our experience the most common mistake in building an airtight house is made by the Plasterers, sorry for that Plasterers! This very rarely has anything to do with the board and finish, although going with traditional wet plastering does offer a significantly better protective barrier for air leakage, in most dwellings this level of air tightness is not needed. The problem we have noticed time and time again is the practise of ‘dot and dab’, the process describes itself but it’s very misleading at least for air testing purposes anyway! When fixing plasterboards to blockwork the adhesive should form a continuous barrier around the whole perimeter of the board to ensure a airtight seal, while only the centre of the board should be dot and dabbed.
We understand that previously this wasn’t common practise, however, with stricter building regulations this is an important method to adopt. In our experience we have met Plasterers who have adopted the new method and often their work results in better Air Test scores, however, with Air Tests still being a relatively new building regulation not all plasterers have adopted this method. So, make sure yours does!
As we said it’s not just one trade, download our builders guide to see how other tradesman can help you pass your test!