Hi there. I had an alteration done to my house +- 1 year ago. They have used wooden trusses with +-6 flat corrugated sheets. Cloth & sealer have been used on the sides. I have damp in the roof & cannot see where it is getting in. I have personally re-sealed the roof with cloth & " raincote" & yet there is one annoying area that keeps on leaking. The strange thing is that it sometimes drips in the area on hot days as well. Please help. Regards