Having a new boiler put in - old flue went directly and vertically out thru flat roof. (No longer meets regs -Boiler and flue being relocated elsewhere).

So I will have a hole approx 150-200 mm diameter when flue is removed.

Should it be patched with timber and new roofing felt -Can 2 layers of top layer felt be used for the patch and what cold adhesive would you recommend?

or should the whole roof be replaced (size approx 4m x 2m)

serenfach, July 2009

u can patch the roof. cut the timber back to the joists, then cut some ply and fix into place. you can buy torch on felt. you will need some torch on underlay and some torch on green mineral. cut to size and heat until the tar is just melting. then fold it down and it will stick. then repeat with the green mineral. i would allow 6 to 8 inches lap onto the existing felt

mel burton, July 2009