My garage

[D.C.]

Ever thought of adding insulation, it is pretty cheap at the moment and you can just staple the stuff on:

£11 for 8mx60cm
Thermal Insulation Foil Roll 600mmx8m - Loft Insulation - Insulation -Building Materials - Wickes

Expanding foam for drafts will obvious help as well,

[kingcreaky]

forgive me for my naivety, and you guys are ALL cleverer than I... Ive been reading your posts!.
I obviously fell asleep in this lesson..surely the condensation will just form behind the carpet/foam/etc whaever it is your sticking to the roof? so essentially you are catching drips? rather than solving the problem... the foam will eventually smell of stagnent water? I dont know...

[wilfy]

forgive me for my naivety, and you guys are ALL cleverer than I... Ive been reading your posts!.
I obviously fell asleep in this lesson..surely the condensation will just form behind the carpet/foam/etc whaever it is your sticking to the roof? so essentially you are catching drips? rather than solving the problem... the foam will eventually smell of stagnent water? I dont know...

on that one.. the way the foam works from what i can tell is that aslong as you glue the stuff straight to the roof and dont leave an air gap then when the warmer air below the roof rises instead of touching a freezing cold tin roof it touches the foam, which i believe adjusts to the temperature quicker than the tin and therefore isnt a cold surface for the air to condense against.

Ever thought of adding insulation, it is pretty cheap at the moment and you can just staple the stuff on:

£11 for 8mx60cm
Thermal Insulation Foil Roll 600mmx8m - Loft Insulation - Insulation -Building Materials - Wickes

Expanding foam for drafts will obvious help as well,

no the problem with this other than that i hate the stuff, it's itchy as hell and i dont want to lose that much head room is how do i staple it to a tin roof?

[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

[wilfy]

i wish i had the cash to do a better job i really do, but the house isnt even ours so i'm reluctant to spend anymore money on the garage than i need to. all i need to do is stop the condensation like i said before i can deal with myself being cold in there and if i have to stick a pet mat or something in the control box for the cnc when its done i can cope with that.

for me now that polystyrene seems to be the best option and going off the price i may even cut strips to go in the deepere parts of the roof before i stick on full sheets over the top, this will reduce the air gap up there and also provide 50mm insulation in places

[GEOFFREY]

Wilfy,point taken about the expense. Afriend of mine insulated his workshop (small factory) by visiting all the local electrical stores and collecting (did them a favour) all the unwanted polystyrne packaging (washing machines, etc.).He then broke it up into small pieces and sealed it into black (non biodegradable) bin bags making like pillows. This worked for him, but was a lot of work, but more importantly virtually no cost.Reards,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

[martin54]

Sorry Wilfy but I think you have just hidden the problem rather than dealing with it & over time you will have problems. You have all those voids that will continue to collect condensation above the insulation you have fitted, it still has to go somewhere so will find it's way through the insulation or just rot it from the inside.