If anyone could help me on this it would be very much appreciated.
I am currently doing a garage conversion with BCO approval. Everything is quite straight forward apart from one thing. I have a cold deck flat roof which the BCO insists is cross ventilated through every joist. I have 13 joists. BCO suggested i fit a ventilated soffit on the outside wall eves, no problem. For the house side he says i need to fit mushroom ventilators for every void between joists. That sounds like a nightmare job. How can i weather proof after installation? My garage roof is a silver rubbery finish which looks like it went on as a liquid. The roof is in very good nick at the moment but if i start making 12 holes across it im afraid i will damage it.
Any help would be great. Thanks.