The previous owner put on an addition and extended the kitchen. Half of the kitchen is below one of the upstairs bedrooms and the other half is roofed and extends into the backyard. I have been having leaks at the vestibule and in the kitchen ever since I moved in five years ago. A neighbour who has experience in these things went onto the little roof with a hose and started spraying water on the windowsill of the bedroom above the kitchen. We re-did the windows and the sill and everything was fine for about two seasons and now its back. I'm tired of people telling me I need a new roof.
Answer:
At least 9 times out of 10, the problem here has to do with the transition from one structure to the other. The addition roof should be the fist thing to look at. If it has been re-sealed, the old seal should have been removed first. If it was removed, the flashings have to be checked for integrity. This does not mean you need a new roof. It means you might need a new roofer looking at the flashings on the existing roof.