IM in the process of converting an attached brick garage into a habitable space. A local builder has given me some ideas and we discussed how he would insulate the walls. His plan is to build a timber stud frame and fill the gaps with 50mm cellotex. The cellotex would be in direct contact with the brickwork with no cavity. The studwork would then be covered with plasterboard and skimmed. Since the garage is single skin brickwork, IM wondering whether this is the correct approach and whether a vapor barrier and/or a cavity should be used? When I questioned the builder he said there was no need for a vapor barier as the cellotex has a silver foil backing and is waterproof.
Thoughts and comments about this approach appreciated
Thoughts and comments about this approach appreciated