I need to replace the felt on our flat roof and the boarding under it at the entry to our house.
It's a shared flat roof and I know from when I was painting the facia that the boarding under the felt has gone as towards the edge where I wasn't walking on it as it was giving way when I tested it.
How do I know that the joists are rotting without pulling the existing roof up as I want to order all parts and do the job in one weekend, also what's the deal when it's a flat roof shared with a neighbour, we previously had arguments with them over the fence at the back of the house so I don't want to go through that again.
I'm thinking of using EPDM rubber roofing on 18mm OSB Boarding, is this correct?