Board between ceiling insulation and tongue and groove?

[carlbanan]

Yes, to create the air gap between the tongue and groove on the rafters and the insulation underneath (partially sloped ceiling), I was thinking of installing some kind of board.

What type of board should I use then? I saw that Byggmax had some cheap kind of board, would that maybe suffice?

And how thick should the batten be between the tongue and groove and the board? I was thinking of using some leftover purlins, or would that be too little?

 

[Styx]

Oil-hardened board (masonite) is what we usually use..
The air gap should ideally be 50mm, but we usually set 22-45 on edge and get 45mm..
It's a good idea to place one in the middle of the space too, so the masonite doesn't bow up against the ceiling - this is especially important in roof trusses where you spray completely tight against the masonite.

 

[ByggaNytt]

http://www.byggahus.se/forum/isolering/50076-material-foer-luftspalt.html
http://www.byggahus.se/forum/isolering/61489-gips-som-vindavledare-i-snedtak.html
http://www.byggahus.se/forum/isolering/50421-luftspaltsbildande-cellplastskivor.html
http://www.byggahus.se/forum/byggmaterial-byggteknik/41743-materialval-till-luftspalt.html

 

[Chinaski]

I have thought of using these:
Product Database

I have also used them as blindbottenskivor.