Re: Re: Airtight details and kit

[Nick Grant]

An interesting approach I heard from a Norwegian (via a friend) timber builder was to concentrate on making the outside of the insulation airtight.

This seemed so counterintuitive that I was sure it was wrong at first.

The argument is that it is easier to make the outside airtight and that if air can't get out of the outside, warm moist indoor air can't get into the insulation – try placing a match in a bottle neck then blowing it into the bottle as a party trick.

Unfortunately I heard this after building our house and we ran the timberwrap/Tyvek horiziontally rather than vertically which would have allowed the joins to be trapped under battens.