I have a bit of celotex left over from a previous project and am thinking of using it to insulate our conservatory roof the celotex is only 25mm thick but i ll probably double it up.
How to insulate roof rafters with celotex.
I ll cut the celotex to fit snugly into the shapes made by the rafters.
If you have a non breathable membrane black roofing felt then you could install 50mm of celotex ga4000 between the rafters and 80mm of celotex ga4000 below the rafters maintaining a 50mm ventilated air path below the felt.
Once up at roof level the between rafter boards can be cut accurately to fit the rafter spacings.
Once up at roof level the between rafter boards can be cut accurately to fit the rafter spacings.
Rigid polyisocyanurate pir foam insulation boards from celotex are among the most thermally efficient commonly available insulation materials on the market.
10mm wider then necessary to ensure a friction fit when installed between the joists.
Celotex polyisocyanurate pir foam insulation boards are easy to cut and handle.
When the boards are tightly butted together the tapered edges of the plasterboard are sealed with scrim tape and jointing compound to form an effective vapour control layer with a high vapour resistance.
It is positioned between the plasterboard and celotex foam insulation.
Celotex polyisocyanurate pir foam insulation boards are easy to cut and handle.
The roof is polycarbonate with timber rafters.
Depending on the specifics of the roof it may be possible to fully fill the rafter depth or in most cases leave a 25mm or 50mm air gap between the top face of the insulation and the sarking membrane.