Attic ceiling joist VCL

pocck

I'm in the process of insulating the attic at joist level in 1970's house. The previous glass wool had faded away, so it was removed and now there is clean ceiling joists and the plasterboard ceiling exposed. The attic is in good condition - no dampness or other issues.

Should a vapor control layer or vapor barrier be placed before I put down glass/rock wool insulation? From the image at the bottom of this page
eco-home-essentials.co.uk/how-to-install-insulation
It seems a VCL can be placed around ceiling joists but any VCL I have seen is taped from the warm side (i.e. like for rafter level insulation). Has anyone put a VCL around ceiling joists from the attic side and if so was its taped from attic side?

listermint

No just lay down the new insulation between the joists and then the next layer 90 degrees to that across the top of that.

Dr_Colossus

Since you've a clean attic you can seal any gaps in the plasterboard below, ie where it meets partitions and around pipes/wires which will help with your air tightness and prevent warm air escaping from below.

If you can't leave electrical wires on top of the heightening insulation I've run them in conduit. Not sure if it makes that much difference but more for peace of mind rather than covering them directly in insulation.

pocck

Thanks for the replies - that makes it easier then. Good point to seal off any gaps i see