I am currently converting my garage into an office, I have built the stud walls. There is a cavity behind them of 50mm between the stud and brick. I have backed all the studs top to bottom with a DPM, can anyone tell me if this is right or wrong? Would it pass building regs?
Depends on your inspector. Usual practice is: Facing masonry cavity breather membrane sheathing board stud wall insulation vapour control layer plasterboard. But that's text book. You might get away with what you have done. The easiest thing to do is simply phone your inspector, they'll let you know straight away what they are prepared to accept.
Er isn’t that “ text book” for timber framed construction, how the hell do you fix breather membrane and sheathing board to the backside of a stud wall when someone has inconveniently put a masonry wall there
It is timber framed construction, technically. Its simple to construct; just time consuming, if done right. Like I said, that's the text book solution. There are a few ways to achieve this retrospectively. But you need to speak to your local authority building control as different authorities have different standards.
Fine for a single length of wall, but as garages tend to have more than one and quite often at right angles, how does one maintain the integrity of the breather membrane