D
DAJ
I've recently replaced an entire flat roof. The existing roof was fairly sound but, as a consequence of an extension being erected part on the flat roof, the direction of fall had to be changed. In addition a sky lite had to be removed.
I first removed all existing felt (not torched on) that had been there for around 20 years. I then removed the planks/decking afterwhich I removed the existing furrings from the joists.
I then fixed replacement furrings to the joists giving a fall along their lengths from each end to a "trough". This also had a fall in a different direction to take the rain water away to a gutter.
I then screwed down 15 x 2400mm x 1200mm x 18mm plywood sheets to the furrings. I sealed all the joints with silicone. I then felted the entire roof. I layed several layers of felt in the trough to help the fall, first layer butt jointed then overlapped.
My intention was to tank the trough "just in case". But first, I thought I'd test the fall with a hose. This I done and was very pleased with the way the water drained from the roof. HOWEVER (I hate those howevers!), I now have a puddle obviously at a low point. My guess is that I hadn't accounted for the possibility that the joists may have had a slight sag in them or the furrings hadn't been cut (by the timber mills) exactly.
Anyway, I can guess away and wonder - the point is, has anyone any suggestions as to how the problem may be resolved. I was thinking of cutting more felt in the shape of a triangle to encourage the water to go where I want it to.
Any help would be helpful (but please , no, should'ves). THANKS!
I first removed all existing felt (not torched on) that had been there for around 20 years. I then removed the planks/decking afterwhich I removed the existing furrings from the joists.
I then fixed replacement furrings to the joists giving a fall along their lengths from each end to a "trough". This also had a fall in a different direction to take the rain water away to a gutter.
I then screwed down 15 x 2400mm x 1200mm x 18mm plywood sheets to the furrings. I sealed all the joints with silicone. I then felted the entire roof. I layed several layers of felt in the trough to help the fall, first layer butt jointed then overlapped.
My intention was to tank the trough "just in case". But first, I thought I'd test the fall with a hose. This I done and was very pleased with the way the water drained from the roof. HOWEVER (I hate those howevers!), I now have a puddle obviously at a low point. My guess is that I hadn't accounted for the possibility that the joists may have had a slight sag in them or the furrings hadn't been cut (by the timber mills) exactly.
Anyway, I can guess away and wonder - the point is, has anyone any suggestions as to how the problem may be resolved. I was thinking of cutting more felt in the shape of a triangle to encourage the water to go where I want it to.
Any help would be helpful (but please , no, should'ves). THANKS!