The speed at which the rain collects at the drain.
Roof drains per square foot.
This reveals that the minimum size for the leader pipe is 5.
The number of roof drains shown should be verified with local code requirements.
For 1 one inch hr.
Sizing data for conventional drainage.
Round spee d catch basins.
According to the chart for 1 8 slope per 12 of pipe for 5 000 square feet of roof area with a 6 per hour of rainfall the required pipe size is 8.
The downspout is the portion of the gutter that drains water away to a safe place on the ground.
0 cubic feet per second cfs peak runoff volume.
Divided by the 4 600 sq.
Use the following formula to determine g p m.
0104 x r x a g p m.
To size the vertical roof drain for the same parameters 5 000 square feet of room area and 6 per hour of rain consult table 1106 2 figure 3.
Hy tech is an authorized distributor of all roof drain manufacturers so you can find what you need when you need it.
Therefore the 100 000 sq.
Measuring the square feet of the roof along with knowledge of local rainstorms is invaluable when.
Equals 32 6 or 33 drains required.
50 000 4 400 11 36.
The result is the number of drains needed.
We also stock many of the top selling drains and parts onsite so most orders ship same day.
Drainage pipe required minimum diameter.
0 gallons 0 cubic feet.
Take the roof s total square footage and divide by the total square footage handled by one drain.
And then determine from the chart below how many roof drains you require.
For example a 3 inch per hour rainfall will build up to a 3 inch depth on a flat roof in one hour at the rate of 1 87 gallons per hour sq.
Or 12 drains required.
Or 0312 gallons per minute sq.
Each drain can handle 4 600 sq.
0 submit your design let nds evaluate and help you with preparation of your submittal drawings and specs.
Using a 10 000 sq.
Roof area the 3 inch rainfall will produce 18 700 gallons in one hour at the rate of 312 gallons per minute.
Each 4 drain size in a 6 hourly rainfall area will accommodate drainage of 3 070 sq.
Gallons per minute r rainfall intensity inches hour a roof area square feet 0104 conversion factor g p m sq.
They come in a variety of shapes tubes chains etc but their goal is to prevent gutters from overflowing and give water somewhere to go.
The next step is to consult table 1106 3 figure 2 to learn the required size of pipe.
The drains should be equally spaced and located symmetrically about the roof.
Area roof will require 100 000 3070 32 5 or 33 roof drains for ideal drainage.
