Flat roof fall?

You answered your question yourself with furrings, depending on the size of fall on the flat roof is dependent on how big the furrings are example for a fall that only 3meters you would use 3 by 2 cut opposite corners to make two equal triangles if you get a level out on it there should be plenty of fall. For a longer stretch you might use 4 by 2 etc, a flat roof is never actually “flat” your looking for a slight pitch of 5 degrees or so. I would personally add more then one outlet two is good three if it doesn’t look over crowded. If your smart you can use furrings going length and width ways to create a funnel point to direct all the water to single hopper however this is very complex and tricky to get right and your better off with multiple outlets. Don’t forget your vapour barrier on the warm roof build up this is very important. It might be worth hiring a professional if your still confused. Regards Frankie BT Roofing Services

you Need to cut to do a 6” wide x 2” deep cutout on top of the joist at the end where the water is running to and fix in 3, 2” tapers, so it forms a box gutter.. so when the water runs down your flat roof to the front, it drops into a 6” wide box gutter and then that tapers down the 2” to the outlet hopper... maybe better fibreglass roof rather than epdm.... hope this helps

The Furrings can be put in at various angles to create a fall to one particular point, but it is more fiddly than a single drop. Personally I would put extra outlets in theparapit wall and have a lencth of guttering leading to the down pipe. With regards to material. I would go for EDPM over fibreglass everytime. Fibreglass is prone to cracking, where as EDPM if installed properly should last 25years plus. Having said that both EDPM and Fibreglass are easily repaired if required.

Only way to cure that problem is have cut to falls insulation then it will go to a direct point will fall 3 ways