Flipping rain..... Leaky roof question

[Woodworks]

A thin membrane will touch the lower edges of your roofing sheets and some condensation will still form but should be much improved. On the advise of a friend I put a sheet of standard poly sheet under one of our tin roofs and it does help. In my workshop I have also added a rigid PU insulation sheets between the rafters and then sealed all gaps with tape or expanding foam and this has completely eliminated condensation on the roof but not cheap.

 

On your previous question I would take Guss109 up on his offer as as the proper foams guns are a pleasure to use.

 

Hope this helps

[blades]

A thin membrane will touch the lower edges of your roofing sheets and some condensation will still form but should be much improved. On the advise of a friend I put a sheet of standard poly sheet under one of our tin roofs and it does help. In my workshop I have also added a rigid PU insulation sheets between the rafters and then sealed all gaps with tape or expanding foam and this has completely eliminated condensation on the roof but not cheap.

 

On your previous question I would take Guss109 up on his offer as as the proper foams guns are a pleasure to use.

 

Hope this helps

 

Thanks for the advice.... I did think about spraying insulation foam (which I believe is much the same as expanding foam) on the underside of the tin, I have heard good reports.... I assume some of the guns spray in a fan effect??

 

After I priced it, it seemed that sarking/membrane was a cheaper (and perhaps better) solution?

 

Yes... The offer from Guss109 was a kind one.

 

Again thanks for the advice

[Woodworks]

If it would help I can take some pictures of the 2 sheds roofs.

[blades]

If it would help I can take some pictures of the 2 sheds roofs.

 

Yeah that would be a great help... Many thanks!!

[tim Ber]

if you can get the foam infills in it will last longer than the gun foam as it will brack down from exposure to air and sun. it is mainly used as filler where it will be cover from sunlight.

[Woodworks]

Here are the pics.

 

Top one is polythene sheet under box profile roofing sheets. This does get some condensation where it touches the sheets and has broken down with the UV over the clear panels.

 

Lower pic is 50mm PU insulation sheet fixed with wooden pads and filled with spray foam and has eliminated condensation in this shed.

 

Sorry not very good pictures as very dark but hopefully you can see enough.

Edited December 28, 2012 by Woodworks

[blades]

Here are the pics.

 

Top one is polythene sheet under box profile roofing sheets. This does get some condensation where it touches the sheets and has broken down with the UV over the clear panels.

 

Lower pic is 50mm PU insulation sheet fixed with wooden pads and filled with spray foam and has eliminated condensation in this shed.

 

Sorry not very good pictures as very dark but hopefully you can see enough.

 

Thanks for that

[Guss109]

The water used to do a tin roof is- ply or osb on the perlins then felt then put on perlins then fix the profile sheeting to them. This way still allows the roof to breath and you won't get condensation in the shed

[blades]

The water used to do a tin roof is- ply or osb on the perlins then felt then put on perlins then fix the profile sheeting to them. This way still allows the roof to breath and you won't get condensation in the shed

 

Cheers Craig