What should be the size of the air gap in the roof, between the interior ceiling and the roof decking? That is, the air gap visible in the eaves. I have read anywhere from 20-50mm. My roof is at a 35-degree angle and will be ventilated via gable vents.
50 mm was recommended by several actors a few years ago but when that construction was assessed as a risk construction regarding mold, I have seen that new recommendations are a maximum of 15mm http://www.traguiden.se/TGtemplates/popup2spalt.aspx?id=7731
I do not know if that construction has been tested with 15 mm is better than 50 mm over time.
It is best to build with insulation above the raw plywood or with a diffusion-open construction.
Thank you for the reply. I am planning to build a so-called warm roof up to the triangle at the top where the gable vents will be located. For the air gaps, you use masonite, right?
On the link you referred to, wind barrier board was recommended but it costs 170 SEK per square meter. That becomes insanely expensive. Is asphalt board not an option?
