Insulated board for loft

[nicholab]

Hi looking for insulated board to go under loftboards. An area of my loft has a floor with no insulations under it. I would like to put down insulation on top of this and then loftboards on top what product can do this?

[caffrey]

Something like kingspan or celotex ? Won't normal rockwool do ? Or even cavity batts ?

[nicholab]

Not really as I got floorboards down already when someone used it for Photography developing.

[caffrey]

Will you be using stilts for the loft boards ? I think those are 150mm so you can get normal insulation under

[difinity]

I removed all of the old rockwool insulation and replaced it with with Celotex as I wanted to board out my loft but keep it insulated. I put 3x2 CLS timber on top of the joists at 90 degrees then put the loft boards on top. You need to have a space between the top of the Celotex/insulation boards and the loft boards otherwise you will have condensation collecting.

The big sheets are unwieldy and expensive from B&Q/Wickes and have to be cut outside of the loft resulting in lots of up and down ladders. I was patient and bought end of job pieces and a few packs from ebay of the smaller boards that go between rafters.

I looked at the stilts but to do a whole loft worked out expensive.

[rad]

Whatever you buy....make sure it fits through the loft hatch!