billyb

Materials market .com is excellent for general materials. They are brokers across a wide range of merchants and have saved me a few quid in the last year.

When you say no condensation below the vapour barrier do you meant the vapour barrier on top of the first layer of OSB (decking)? Also, where are you in the UK? I'm looking to do exactly what you've had done in a garden room and trying to reassure myself it'll be fine :-)