Myth Busters – Air Tightness Testing
Find out the FACTS from the FICTION...
Pressure Testing is unnecessary for leak detection
Though you may be able to find common leaks without pressure testing, if you want to ensure that you have found all the leaks, and you want to give the customer that assurance, pressure testing is essential. It is also a Part L Building Regulation requirement too!
Your building can not be too airtight
From your Design SAP Calculations, you will have been given a Design Air Permeability (DAP). This is the rating which your building must achieve for its air tightness test.
However, if the build achieves an Air Permeability below 3 (m³.h¯¹.m¯²@50Pa) with standard ventilation (trickle vents & mechanical extractors) - your building will require more ventilation installing to combat this.
Boiler flue cowlings work
Generally made of rubber, the cowling will fit around the flue to cover the hole required for the flue to exit the building. Aesthetically it looks great, however the vast majority of them are not airtight and will require the hole to be seal/foamed.
It will be fine to leave skirtings off with no sealing behind kitchen cabinets
This is one of the most common faults, and often hardest to fix in standard brick and block builds. Leaving skirting off allows for cabinets to be installed flush with the wall but leaves an air gap if not sealed properly!
Rockwool is a sufficient sealing material
This is most certainly not the case. Industry standards class this type of sealing as a temporary seal which must be noted as a deviation from the standard test procedure.
UKBC offers ATTMA accredited Air Permeability Tests for residential and commercial buildings. You are required by law to make sure your development is sufficiently airtight. Air pressure testing is required by Part L1A and L2A (England & Wales), Section 6 (Scotland) or Part F1 (Northern Ireland) of The Building Regulations.