I'm in the process of recovering a flat roof, currently the drainage is a 75mm roof penetration which, whilst adequate, could be better. This drain connects into a 110mm soil pipe vent just under the roof level. Currently the Soil stack extends to just above the parapet level but i'm wondering if it is possible / advisable to cut it off flush with the roof to add an additional drain path. The vent is well away from any "openings". I've had a look at the building regs and I cant see anything that says I shouldnt but I may have missed something or there may be other factors that I haven't considered.
Cheers
Gareth
Cheers
Gareth
