Can I insulate under a VCL?

[Red Squirrel]

I'd like to add additional insulation to a vaulted ceiling with exposed rafters by adding 70mm foil backed celotex between the rafters and plasterboarding over.

My concern is that there is an existing VCL (polythene sheet) that I'd be insulating underneath. The existing roof consists of 80mm joists/15mm fibreboard/VCL/fiberglass mat/felt//baton/tiles.

Would this cause problems later on?

 

[catlad]

Can't see why it would cause problems.

 

[Red Squirrel]

Thanks for replying. I was worrying about having a VCL sandwich and any moisture buildup inside.

 

[catlad]

Shouldn't be a problem as long as you install a new vcl once you have insulated.