General air tightness topics
Spray foam insulation is still a popular insulation method here in Ireland, whilst building regulations of other European countries do not allow this kind of insulation at all. In the light of recent events, we´d like to state some details about the air tightness and vapour behaviour of spray foam (again).
A qualified air tightness test does not require more than 7-8 test report pages or an endless list of calibration certificates. A serious air tightness test takes approx. 2-3 hours for a dwelling and includes important details like the calculation of the building dimensions and a leakage detection. Also the quantity of performed air tightness tests is not an indicator for quality.
From 01/01/2019 the revised Building Regulation for Connservation of Fuel and Energy (Part L) requires lower maximum values for the air permeability of new buildings and deep retrofits. We think it´s a first step into the right direction, but the mandatory values for air tightness are still too high, especially for common technologies like heat pumps and heat recovery ventilation. Our aim is and will remain max. 1.5 ACH (air changes per hour), wherever we´r
Good air tightness is not dependent to a certain brand or product - the secret of how to achieve air tightness values for nZEB or even Passive House standard is the overall strategy and quality of workmanship.
When selecting the right insulation material for Irish homes, please remember that the insulation performance is not the only criteria for choosing the right insulation material and strategy.
Thermal imaging is a great support for detecting leakages in the air tightness and thermal envelope. It can be used to secure the installation quality in new builds as well as monitoring existing buildings for heat loss.
The most insulation layers in domestic buildings require a strategy for air tightness & vapour control. Otherwise the thermal insulation performance will be degraded and the risk for condensation in the structure rises. Unfortunately some spray foam installation companies in Ireland do still promote their product/ service as unique strategy where no further attention is required.