Help re Insulating a wooden shed with Kingspan/Celotex

[fluffybunny]

Hi all

I'm new but need a bit of advice...

We've had a new wooden shed and we're going to put a pool table and dartboard in the for our teenage kids to go out there.

We want to insulate it and then just put OSB boards up (or possibly pallet wood) so that hopefully it won't be too chilly in there. The depth of the walls are 64mm...I've had 50mm Celotex so there'll be a 14mm air gap.

What I want to know is , with Celotex, do I also need a membrane? I've had differing opinions from friends where some have said I need it and others have said I don't. I didn't think I did....I was just going to put the sheets up against the shed wall and then put the boards up.

Any advice would be greatly appreciated

Thank you in advance

 

[John D v2.0]

You need one on the outside if you need to stop water getting through (same as under roof tiles) and it must be breathable.
You need one inside if there's going to be humidity inside and there's a risk of condensation in the structure, that can be polythene or something cheap like that.