Replacing foil backed plasterboard ceiling

[Rowly13]

Currently ripping out an old bathroom to refurb and the ceiling had to come down due to bad solder joints and leaking pipes above. It will now have a toilet and basin only.

The plasterboard that has been taken down was foil backed which I understand is a vapour barrier. This is in a single story extension to the front of the house. What would of been the reason for the barrier? I assume to control the amount of vapour entering the cold roof space above. The foil backed plasterboard also extends to the porch next to the cloakroom which is in the same extension.

If I do need to replace the vapour barrier can I use the polythene sheeting to give me the same result?

Thanks.

 

[frutbunn]

Polythene is actually better as a vapour barrier.

 

[Rowly13]

You'd say it was worth replacing the vapour barrier then? In guessing it was put in for a reason. Just threw me as every loft I've been in I've never noticed foil backed below the insulation.

 

[Rowly13]

Guessing I'd need to use an adhesive/sealant round the edges of the polythene too to make sure it's as effective as possible.

 

[frutbunn]

Its not required by B Regs so thats why you don't see them much. I believe they are more common in Europe as they are required by legislation.

 

[dontbelieveawordofit]

why don’t you just replace like for like.
the foil back have thermal properties that polythene doesnt.