A large roof is going to move a lot of water which means the downspout locations may need to be adjust to compensate.
How much clearnce do you need around a roof drain.
The result is the number of drains needed.
The national kitchen bath association requires at least 24 inches clearance in front of a toilet.
Take the roof s total square footage and divide by the total square footage handled by one drain.
Zurn makes it easy to size roof drains.
When sizing roof drains the limiting factor for the amount of water each drain will carry away is the size of leader therefore increasing.
Overflow drains shall be the same size as the roof drains with the inlet flow line two inches above the low point of the roof and shall be installed independent from the roof drains.
By the 1997 edition of the upc section 1101 11 2 had been added that completely prescribed where and how secondary roof drainage was to be provided.
Moreover the nkba recommends 32 inches from the center of the toilet waste line to the center.
And 4 area handled by each drain.
1 rate of precipitation.
3 size of leader required.
2 total area of roof.
The four things you will need to know are.
A high slope moves water more quickly and if gutters have trouble dealing with a lot of water in a short period of time an extra downspout can alleviate that issue.
In some cases drains can be offset to rise up in walls to avoid cleanout covers in high traffic areas.
50 000 4 400 11 36.
Or 12 drains required.