I have a dorma Bungalow, and the lead lined gulley coming down from an apex above the porch keeps splitting and letting water in. Periodically I have to get it plugged. I was told that when it was installed it should have been done in two seperate pieces not one. I want the lead replaced with Fibre glass. I understand the roof was replaced in 1979 with tiles. There had been a fire caused by decorators with a blow torch and a birds nest.