Rigid Insulation in the Ceiling

[D2WW]

Hi all,
Am replacing the (very) old fibreglass in my ceiling with some foil backed rigid insulation between the joists, then putting the fibreglass over it. My problem is, how to make sure I don't get thermal looping between the plasterboard and the Xtratherm, other than pushing it flush and hoping for the best.

 

[granda]

thermal looping is caused by air circulating (convection) between the two materials, reducing the effectiveness of the insulation......but i suspect you already know this, however if the two insualtion materials are fitted snugly together, no gaps, you will not get thermal looping.

 

[D2WW]

I spoke to a guy from Xtratherm who suggested using a can of expanding foam filler to fill in any gaps. Will have to be very careful about any gases given off though.