fred wrote:
In article , Stuart
Noble writes
RubberBiker wrote:
Kingspan/celotex, or kingspan/celotex-backed plasterboard.

http://www.celotex.co.uk/Products/Ce...Celotex-GA3000

http://www.celotex.co.uk/Products/Ce...Celotex-PL3000

Jablite is cheaper, and probably adequate for a garage.

Just to be clear to the o/p though, it is an inferior product, requiring
5" to get the same insulating effect as 3" of Celotex or Kingspan.

Sure, but any insulation makes a big difference to a garage. I'd
probably go for 25mm celotex as a balance between price and loss of space