Cold Flat Roof Membrane

[matlob]

Hi,

Another question

I have a cold flat roof being installed as below

Where would I place the membrane? Over the joists above the insulation or below the joists before the plasterboard goes on

There is airflow between the firing strips above the insulation so not sure If I should have something there?

Thanks for any help

 

[Deluks]

Your vapour barrier membrane should go over the joists before plasterboarding. Or use foil backed plasterboard, (or both to be on the safe side)

Where does the insulation go in that wall cavity? There's a risk of cold bridging there where the ceiling meets the wall.

One assumes that those airbricks are sleeved and don't vent into the wall cavity?

 

[matlob]

Thanks for the reply!

Was going to take the cavity insulation level with the top of the joists with a cavity closer on top. If not a cavity closer should it be closed some other way?

Will be two air bricks with sleeves yep