Corrugated Steel Garage Roof Condensation

[rvp]

Hi fellas, thought I'd throw this one out there and hopefully get some decent advice.

Here goes.

I have a major condensation problem with my Garage roof due to it being made with box profile steel sheeting.

Untitled

• rvp
• 20 Jan 2015
• 1

Untitled

• rvp
• 20 Jan 2015
• 1

Replacing the Roof with EPDM etc is NOT an option so looking for a remedy.

I have done alot of research on this and making it a cold roof seems the answer so I am planning on sticking 50mm polystyrene boards up leaving a 50mm air gap with a membrane below the insulation.

Do I have the right idea here? would this cure my problem??

Finally failing that, I did come across this which looks great on paper!

http://www.grafoproducts.co.uk/selfapp.htm

 

[oldbutnotdead]

Not sure about putting membrane under the rafters- assuming you've got some sort of ventilation under the tin sheets I think you'll be better off with something impermeable like B & Q tarpaulins (so that warm air carrying water vapour can't get up into the insulation). But the whole condensation sketch is littered with pitfalls...

That link you put up looks interesting- if you try it can you post the results?

 

[rvp]

Not sure about putting membrane under the rafters- assuming you've got some sort of ventilation under the tin sheets I think you'll be better off with something impermeable like B & Q tarpaulins (so that warm air carrying water vapour can't get up into the insulation). But the whole condensation sketch is littered with pitfalls...

That link you put up looks interesting- if you try it can you post the results?

Thanks for the reply, I'll certainly post up the results if I go on to use that stuff.

Anyone else have any advice?

 

[Burnerman]

I have a very similar situation......I have put particle board on the rafters, and nothing between that and the steel roof, and I have the soffits open (just) at the gutter end.
No rot after 10 years, but the rafters were tantalised originally so it wouldn't be any big deal anyway.
It's an excellent roof covering you have, but in the winter there's bloody drips everywhere without some sort of ceiling.
John

 

[rvp]

I have a very similar situation......I have put particle board on the rafters, and nothing between that and the steel roof, and I have the soffits open (just) at the gutter end.
No rot after 10 years, but the rafters were tantalised originally so it wouldn't be any big deal anyway.
It's an excellent roof covering you have, but in the winter there's bloody drips everywhere without some sort of ceiling.
John

Hi John,

Thanks for the response. Do you suffer from condensation like me then?

I am just weighing up my best options, just got a peice back from the company I linked to earlier, £3.13 per KG and that covers 1m2.

It certainly looks the part going off the website but not sure if it's too good to be true!

 

[Burnerman]

Suffer from condensation? I'd say so.....my garage is a concrete panel pre fab, steel roof and in winter time is like it's raining once the frost lifts
If that product of yours works it could well be worth a try.....at least it can't do any damage where it is!
John

 

[oldbutnotdead]

I am just weighing up my best options, just got a peice back from the company I linked to earlier, £3.13 per KG and that covers 1m2.

£3.13 per sq metre? Is that net or gross? Whichever it's a bit pricey considering all it is going to do is reduce the condensation- your original polystyrene and tarpaulin sketch will only be about £4/sq m and will make the space more comfortable as well..

 

[rvp]

I am just weighing up my best options, just got a peice back from the company I linked to earlier, £3.13 per KG and that covers 1m2.

£3.13 per sq metre? Is that net or gross? Whichever it's a bit pricey considering all it is going to do is reduce the condensation- your original polystyrene and tarpaulin sketch will only be about £4/sq m and will make the space more comfortable as well..

I believe that is before VAT and delivery so maybe it will be about the same really as my polystyrene idea although it does seem like it stops condensation 100% if their site is to be believed.

Undecided I must say at the moment - just want a usable storage space really.

 

[oldbutnotdead]

The advantage of that spray-on goo is it won't do any damage (whereas if you end up with lots of water trapped near the joists they might rot out). Another option might be (though I'm sure there are cons to this idea) spray the tin sheets with expanding foam. Dunno if it would stick though and it would probably look really ugly.

 

[rvp]

The advantage of that spray-on goo is it won't do any damage (whereas if you end up with lots of water trapped near the joists they might rot out). Another option might be (though I'm sure there are cons to this idea) spray the tin sheets with expanding foam. Dunno if it would stick though and it would probably look really ugly.

Yeah looked into expandable foam idea but probably be very messy and cumbersome.

I am not too fussed about it looking ugly to be honest though just want the condensation gone!

 

[rvp]

Update.

Got a price back in order to cover the area, quoted us £92 delivered.

Decisions decisions