We all want to achieve the best values for air tightness for our homes.
Good air tightness is not subjected to the brand of air tight products you use, but definitely how good and accurate they have been installed. It´s as always - the devil is in the detail.
One of the most forgotten or bad treated detail regarding air tightness can be found in every socket. As far as I know, the conduits here in Ireland have to be used to protect the wires against aggressive substances coming out of the blockwork. Unfortunately every conduit creates a small draught which is comparable to a chimney. The photo underneath shows the amount of air infiltration during an air tight pre-test @50pa pressure difference.
The value of 0.35m/s was measured in almost every socket in the house. This means, every socket is creating an air Infiltration of 1.26 liter per hour in case the conduits will not be sealed with an approriate sealant. We wouldn´t recommend the use of expanding foam, as seen during another test a few months ago.
The most expanding foams here in Ireland are not good enough regarding fire protection. And the air tightness will get definitely weak, as soon as the electrician has to remove the most of the foam to get the 2nd fix of his installation done.
We´ll probably have a suitable sealant solution in stock soon, which creates an air tight sealing without destroying the fire behaviour.