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.
The main areas for air infiltration through the air tightness layer are penetrations through the layer. It is essential to have every single penetration sealed with an appropriate sealing strategy. We at prodomo Ireland would like to give you some inspiration about functional air tight sealing strategies.
Air tight paint is one of the greatest inventions for air tightness and we highly recommend the use, because painting is mostly easier and more efficient than taping. But unfortunately air tight paint is not suitable for external applications, where water tightness and UV resistance is the key. That´s the reason why Belgaplastics has been developed the new Belgacoat LR (Liquid Rubber).
Monolithic membranes are the better choice to wrap the building envelope of timber frame structures externally. Especially the popular (partly open) facade claddings require such a membrane with a long lasting UV resistance. Why should you select copmpetitors products with UV resistance levels of just a few months, when you can have the Belgawall B1 with a guaranteed UV resistance of 10 years and an outstanding B1 fire rating on top?
A common practice for air tightness here in Ireland is, to wrap the hollow core slab with air tight membrane. Attention is needed for some details, to achieve the best possible air tightness performance.
Multifoils like SuperQuilt are becoming more popular for insulation applications. Because of their high vapour resistance attention is needed, when installing such layers to standard roof structures, made of timber.
This detail can be found in many houses during the construction stage. I guess that in the most cases someone will put the window board or the kitchen work top on top and everything is covered. The occupier is wondering thereafter where the draughts around the window do come from.....