What vapour barrier? Breathable or non breathable?

[Chaser]

Scenario is a single skin concrete block wall between unheated garage and heated utility room. On the warm side I've studded it, added 50mm of foil faced insulation and plan to overboard this with 67.5mm backed plasterboard.

I've been advised that I need a vapour barrier between the wall and stud, but don't know if it's breathable or a simple polythene barrier?

Can anyone advise?

 

[geraldthehamster]

A vapour barrier is just that. it isn't breathable.

 

[^woody^]

You don't even need a vapour barrier in that situation.

 

[Chaser]

You don't even need a vapour barrier in that situation.

I did think that, but the building inspector has asked for one. I expected it to be a poly barrier at best but he wants breathable membrane, which I suspect is like roofing stuff.

 

[Notch7]

I did think that, but the building inspector has asked for one. I expected it to be a poly barrier at best but he wants breathable membrane, which I suspect is like roofing stuff.

Are you saying the building inspector wants you to remove the insulation and studs and fit a membrane against the garage wall?

 

[Chaser]

Yes. You can imagine my delight.

 

[stuart45]

A breather membrane is normally used where there is likely to be water penetrating the structure such as below roof tiles, tile hanging, sheathing on timber framed panels etc. It stops water coming in but allows moisture in the air to escape. Can't see the point of it in your situation.

 

[^woody^]

Your inspector had not got a clue. It's an internal wall! Tell him/her to do one.

 

[Chaser]

Cheers all.