I have a four unit apartment building with a flat roof in Washington DC. It's two stories with two units on each floor. The top two units have experienced leaks in the ceilings, to the point where the dry wall in one of the units is actually sagging. The leaking only occurs when it rains hard I'm in the process of getting quotes from different roofers, and so far I'm recieving very different estimates. When I bought the building 18 months ago, it passed the roofing inspection. The roof was installed around 5 years ago.
The first roofer actually went on top of the roof, and looked for possible problem areas. He said the roof was pretty good(made of ruberoid bitumen?) and that he could tell it was pretty new. However, he said the flashing was done in an inferior manner. He recommended rdoing the front flashing wall, and around the vent pipes, skylght and where ever it's needed. For this he'd charge $3500
The second roofer, didn't go on top of the building(the receptionist told him it was an estimate for aluminum siding so he didn't have a ladder with him). I showed him the leaks from inside the two units, and he said I needed to replace the whole roof. He said he could do it for $6200.
I'm still taking estimates, but it seems strange that the second roofer could redo my entire roof for less than twice what the first roofer would charge me. Any insights, or thoughts would be appreciated.