My garage

[wilfy]

i'm now thinking of using something like this

Polystyrene 25mmx1200x2.4m - Polystyrene Insulation - Insulation -Building Materials - Wickes

i'm still not sure if i need to shape something like that to the contours of the roof or not, preferably i'd sheet the whole roof in that, fill any gaps to the sides with expanding foam and line the joins with that foil tape, but i'm not sure if condensaton will still build up in the air gap or not?? could anyone possibly comment?

[GEOFFREY]

Wilfy, I have just finished (well nearly, there'l still be bits to finish in 5 years time according to the fuhrer) building my house and have had many conversations with the building inspector about "warm roof construction. I think that is probably the best solution,but 50mm foam would be better. the problem is water vapour which will pass through almost anything, so needs to be completely sealed on the warm side. Any moisture the that does penetrate the internal vapour barrier will condense either in the insulation(interstitial) or on the underside of the roof sheet.

The sprayed foam insualtion would almost certainly provide both the insulation, vapour barrier, seal any voids and sticks like ----, however this is probably quite expensive.

Good luck, G

[D.C.]

i'm now thinking of using something like this

Polystyrene 25mmx1200x2.4m - Polystyrene Insulation - Insulation -Building Materials - Wickes

i'm still not sure if i need to shape something like that to the contours of the roof or not, preferably i'd sheet the whole roof in that, fill any gaps to the sides with expanding foam and line the joins with that foil tape, but i'm not sure if condensaton will still build up in the air gap or not?? could anyone possibly comment?

You didn't bother clicking the link I posted did you?

The stuff I linked is basically a thick pastic bubble wrap type stuff coated with shiny thermal film. It is cheaper per sqm than the stuff you are looking at and performs better as insulation.

If you read the comments, people have used this exact stuff for your exact situation and seem to be pleased with the result. ;)

[wilfy]

You didn't bother clicking the link I posted did you?

The stuff I linked is basically a thick pastic bubble wrap type stuff coated with shiny thermal film. It is cheaper per sqm than the stuff you are looking at and performs better as insulation.

If you read the comments, people have used this exact stuff for your exact situation and seem to be pleased with the result. ;)

i'll be honest i looked at the text and thought it was normal loft insulation.. doh... but my point still stands, how do i get it to stick to the tin roof??

i've sorted something now anyway, expanding foam round the sides to seal it off, polystyrene siliconed to the roof and foil tape to seal the joins and flashing tape to cover the screws on the roof