I have a 1920's house with an integral garage and bathroom above. I want to put a small hatch in the garage ceiling to access a shower trap in the bathroom. The existing ceiling is plaster on expanded metal, ie non combustible. Presumably making a hatch cover out of plywood is not ok. I'm thinking it has to be made from something fire resistant.
Any advice on what material to use would be appreciated.
Any advice on what material to use would be appreciated.