Foil Backed Plasterboard

[Pacman52]

Hi all - Would someone please be able to give advice on foil backed plasterboard please.

I'm currently in the process of planning a new garden office. It will be timber framed, externally covered with 18mm OSB and wrapped with Tyvek, then clad with 19mm Shiplap Internally I plan to use 90mm Quinn-Therm PIR board in the frame. Its going to have a warm roof if that makes any difference.

I know foil back plasterboard acts as a vapour barrier and I have no problem putting this in if need be but currently the project is running over budget and I'm wondering if I actually need to use it rather than just standard plasterboard which is a lot cheaper. It will be skimmed over once done (by a plasterer not me !).

Would be grateful for any advice offered - Many thanks

Paul

 

[Vincey]

What’s the difference in cost out of curiosity?
£20/£30 ? For the boards in the whole room

 

[brimplas1]

I personally wouldn't use foil boards but put visqueen over the insulation and stud work then just board it...

 

[Tinytom]

I personally wouldn't use foil boards but put visqueen over the insulation and stud work then just board it...

This.
or staple roofing membrane over, it’s breathable too then

 

[essexandy]

This.
or staple roofing membrane over, it’s breathable too then

But the whole point is it's supposed to be a vapour barrier and not breath.

 

[Brimstone]

You will defo need a vapour barrier. Yes, a warm roof makes a big difference.
As you're at the planning stage you could alter your budget, best option, or size of office. Or consider visqueeen and alternative internal inner skin, like taped joints, or, or, 9.5mm osb or summat the chippies could fix and avoid spending money on that 'orribly expensive plasterer.
Must lie down..not feeling well..

 

[Tinytom]

But the whole point is it's supposed to be a vapour barrier and not breath.

True, just an idea

 

[brimplas1]

But the whole point is it's supposed to be a vapour barrier and not breath.

Just done a single skin garage conversion and the spec off building regs was to put breathable membrane on the back side of the stud, kingspan in the stud and visqueen on the warm side of the insulation...

 

[Deleted member 32554]

Advantage of plastic is no gaps from dodgy boarding

 

[smoother09]

Just use vapour barrier wtf u talking about foil back boards for ? Stop ducking around and do it properly!

 

[hollybank]

I havnt seen foil backed boards for a while in the merchants.
Are they still doing them?

 

[essexandy]

Just use vapour barrier wtf u talking about foil back boards for ? Stop ducking around and do it properly!

Foil backed boards are for vapour barrier.
Spec'd on loads of jobs.

 

[ChrispyUK]

I havnt seen foil backed boards for a while in the merchants.
Are they still doing them?

Yes.

 

[theshed]

Use clear plastic for vapour barrier. Don't forget to lap it 12in onto the ceiling to go under plasterboard.

 

[Pacman52]

What’s the difference in cost out of curiosity?
£20/£30 ? For the boards in the whole room

Far point actually - it would be a bigger difference than £20-30 but probably no more than £90/100 so considering how much the whole project is costed at so far that is not the end of the world !

 

[Pacman52]

Thanks all for your replies I will look at Visqueen or go with a 'plastic' barrier now - I did a bit of a search on google last night as well and that was pretty much the same consensus. You may of guessed I'm not trade so really appreciate the advice !