Originally Posted by Tim M
Quite a timely thread. I had a roofer round the morning to quote for a cottage I'm currently renovating. He suggested a new type of roofing felt that incorporates the insulation. I can't get my head around this! Was planning to use Celotex and expanding foam to fill the gaps. Any thoughts?
I'd imagine he's talking about a multi foil type insulation Triiso or YBS.
we did our current barn conversion 5 years ago and used 150mm kingspan in between the rafters with 25mm kingspan backed plasterboard over however the building inspector suggested we use Triiso in the walls as it's much thinner and you reduce the room size by much less than using kingspan
The house retains heat very well but can't say which is working best
There was a lot of negativity about the multifoil insulations back then but it seems more accepted as a viable alternative now
We just bought a 250 year old farmhouse and intend to line all the walls with multifoil this time but we will probably use a combination of foil and kingspan in the sloping ceilings and rock wool in the flat loft sections where we can afford to lose 250 - 300mm in height
I think with most insulation products with the exception of rock wool the installation instructions need to be followed to the letter to provide a complete envelope.If you get a contractor who starts to cut corners and leaves any gaps then you start to lose effectiveness
Lots of info on installations on kingspan Triiso and YBS websites