If Thermafleece aids breathing will this affect the air tightness of my building?
Air tightness and breathability are two separate issues. Air tightness concentrates on mass seepage of air through the building fabric which is a visual measurement that can be taken under pressure, for instance a draught through a letter box. Breathability is looking at the building fabric’s ability to adsorb and desorb water vapour. A ‘breathing’ house can aid a healthy living environment but the amount of vapour that the building will breathe cannot be measured on the same scale as air tightness. Therefore airtight buildings can still be breathable.
