matthew howden
Hi Jenny. Sorry to say but without seeing the job it will be hard to give any advice. The best i can offer is to locate a well established, expert roofer with vast experience. As it is not an obvious issue, a 'newby', although good at what they do, may not experienced enough to detect any small technical defects that will cause the leak. Hope this helps and good luck Matt - A.A. Roofing,