We are currently in the middle of getting of roof tiles replaced and as part of the deal, as the attic area is open, it was agreed that the roofer would OSB under the rafters and insulate with 50mm celotex before putting on the membrane, battens and tiles.
I came home and they have already stripped both sides of the roof. put on the membrane and battens but have not yet boarded out the underside of the joists.
I have now found that they have put rolls of HYBRIS HC90C-UK insulation ready to fit afterwards and sheets of ply (not sure what thickness or grade).
What is HYBRIS and how does it perform compared to Celotex? Is it fire resistant? Is it ok for a useable roof space?
I came home and they have already stripped both sides of the roof. put on the membrane and battens but have not yet boarded out the underside of the joists.
I have now found that they have put rolls of HYBRIS HC90C-UK insulation ready to fit afterwards and sheets of ply (not sure what thickness or grade).
What is HYBRIS and how does it perform compared to Celotex? Is it fire resistant? Is it ok for a useable roof space?