With our last post we introduced the issue of air tightness and focused on its importance, and the ways we can measure it. The upcoming paragraph, instead, will be centred on timber buildings:
The first thing to consider are construction materials.
Air proof elements could be, for example, plaster, cloths and membranes (to envelope all the joints and interruptions), tapes, panels (OSB, plasterboards, fibrocement…), multi-layered timber panels, and so on.
Platform frame walls
In a platform frame wall, air tightness is usually performed by the internal OSB panel, which works also as wind brace and vapour barrier: it is particularly important, then, to seal all joints with tapes.
Along the roof’s surface, on the board, a waterproof vapour barrier will be placed; it will be, eventually, folded to keep the integrity of the air sealing layer.
The air tightness of a multi-layered panel depends on the number of layers and the gluing technique (the greater the number of layers and the glued surface, the better the sealing). However, to avoid problems, it is advisable to consult the manufacturer’s certificate.
Non-glued CLT walls
Every hole passing through the timber envelope represents a criticality, because every interruption of the air tightness layer must be well sealed, choosing flexible and easy-to-lay materials.
Do you need any clarifications? Do you have in mind other details to ask us about? Don’t forget to e-mail us, and we will give you an answer soon!