Loft Insulation

[diycooper]

I have just raised my joists in my loft from 3 x 2 to 7 x 2 to insulate and board. I will also be insulating rafters to get the best insulation possible. As the insulation depth for the joist is required to be 10 inch (270mm) and I only going to be able to fit in 170 mm, I was thinking of stapling a aluminum bubble insulation over the joist with the rockwool in before boarding for added insulation. Will this make much difference for the cost and is there any problems in doing this ?


Thanks

 

[tony1851]

It will make absolutely no difference whatsoever, and you would be throwing your money away.

The reflective foil insulation products depend almost entirely on the foil itself to reflect radiant heat. As such, to be at all effective, they need to have a closed air gap each side of the foil to avoid transmitting heat by conduction. Sandwiching them between other materials defeats the object.

Don't waste your time and money.