Roof Drains Really!!

What has happened to the roof drain 30 years ago roof drains were rarely replaced at reroof time Today it has become a common occurrence Why?

What makes a good roof drain Durability Low height of free area in assembled drain 1 ½” drain bolts Integral gravel stop No plastic Sump twice pipe diameter

What makes a good installation Drain being installed at correct elevation What is that elevation? Roof insulation minus height of free area drainage Overflow installed so as to allow primary system to reach it’s designed capacity.

ponding

Wrong Right

Drain Elevation

ASPE/IAPMO Flow test criteria Standardization of test rig IPC is adopting the test criteria in to the 2015 code. All manufacturers will be required to provide test results

DRAIN WITHOUT DRAIN PIPE Water head (inch) 1" 2" 3" 4" 5" 6" Flow of water into box (gpm) 118 202 402 616 714 870 Velocity of flow (ft/s) 1.8 4.5 6.2 7.8 3.3 3.2 DRAIN WITH 10 FT PIPE 120 192 397 604 704 866 Velocity in drain pipe (ft/s) 2.4 8.2 8.8 8.9 8.6 Pressure in drain pipe (in. W.C) 7.4 7.6 6.9 5.5 5.3 5.6 DRAIN WITH MODIFIED PIPES 117 210 401 596 916 1164 Velocity in 1st stack (ft/s) 2.9 4.2 5.0 7.0 Velocity in horizontal pipe (ft/s) 0.5 5.2 6.5 7.3 Velocity in 2nd stack (ft/s) 5.9 6.4 8.0 7.9 Pressure in 1st stack (in. W.C) 15.5 17.6 17.3 18.1 14.2 -5.4 Pressure in horizontal pipe (in. W.C) -13.2 -13.3 -13.8 -11.7 -10.6 Pressure in 2nd stack (in. W.C) 6.0 1.9 -11.0 -22.4 -34.3 Flow Water Head gpm Inch-W.C 100 1.8 200 2.7 300 5.2 400 N/A 500 600 Flow Water Head Pipe Press. Velocity gpm Inch-W.C inch-W.C ft/s 100 1.9 2.1 3.1 200 2.3 1.2 3.5 300 3.4 -5.2 4.1 400 4.0 -12.5 4.3 500 4.4 -20.7 5.1 600 4.7 -25.8 5.6 700 4.9 -28.6 5.8 800 -36.8 6.3 900 5.2 -45.2 6.7 1000 N/A

ASME A112.6.4 is in revision Bringing larger sizes in to standard Roof drain with integral overflow is being added Suggestion was made to remove thickness requirements from the standard.

Green roof

Green Roof issues What is the proper way to install a drain into a green roof, well that depends on the green roof How do you make sure it will always drain Are the new drain configurations safe? Have they been flow tested? How will maintenance be performed?

Only 20 minutes under perfect conditions

Drainage must be unobstructed

Siphonic Drains Is a great idea and works, but what happens after it is installed? Does anything in a building stay the same for the life of the building What about building code variances It gets disassembled and reassembled four to five times at least throughout the life of the building. But by who?

The Roofer!!!