I'm thinking about having my leaking garage roof repaired & since I am ill health retired I will need to get a company to carry out the work. The garage measures 20' x 12' & has a 3" drop from one side to the other. Can anyone give me a ballpark figure to have it done with EPDM, the existing felt will need removing & since it is only sarking beneath the felt then the roof will probably need sheeting before new finish is installed. I am in Ayr, Scotland.