Can't say can't see it but at least a week if you've no idea what you are doing and the neighbouring garage owner wont be too happy if you cause theirs to leak. Get some one in with knowledge on roofing. Got no idea where the other garages join yours, or whether its a middle garage or end garage, or which way the 'fall' is. Felt cold layed last about 10yrs if done properly, A ruberoid roof last about 50yrs but a specialist job is most cases comparable to felt. Try searching the net for flat roof contractors.
Bob, November 2006
