Breatherquilt?

[sad2k]

Hi,
Planning to replace the roof (membrane, battens, tiles) in the 1970s terraced house, was planning to put in a breathable membrane (eg roofshield), however one of the roofers suggested breatherquilt instead (https://ybsinsulation.com/brands/breatherquilt/). Any thoughts about it? I'm a bit concerned because I don't see a lot of references to it in forums/youtube/people's building projects?
Or is it better to have just a normal breathable membrane and celotex/etc in the rafters internally?

 

[freddiemercurystwin]

Why would you bother insulating at rafter level? Or do you have a loft conversion?

 

[sad2k]

In general cause I like it more and don't want to have messy mineral wool on the floor (which I do now). But I don't think it's massively important to this question.

 

[freddiemercurystwin]

You'll be paying to heat your empty loft space then, also if you're insulation needs to get up to the thickness required by Building Control then you'll need a load of PIR insulation between the rafters too. Superquilts were all the rage 20 years ago until the testing was found to be flawed after which they don't comply with anything when used on their own.

 

[sad2k]

You'll be paying to heat your empty loft space then, also if you're insulation needs to get up to the thickness required by Building Control then you'll need a load of PIR insulation between the rafters too. Superquilts were all the rage 20 years ago until the testing was found to be flawed after which they don't comply with anything when used on their own.

thats what I was afraid of.. so just a normal breathable membrane then?

 

[freddiemercurystwin]

Are you upgrading the insulation to meet Building Control requirements for replacement roofs?

 

[sad2k]

its currently at the joists, up to the regs

 

[freddiemercurystwin]

Yes a normal breathable membrane something like Klober Permo Forte is good, I'd still add a couple of roof tile vents near the eaves on each side though.

 

[robinbanks]

don't want to have messy mineral wool on the floor

Install loft legs and board out on top of the wool; gives you an effective insulation layer and also clean space to store junk