That is what is wrong.
How to size roof leader collection pipe size.
Using figure 8 the 312 g p m.
Each drain will carry away is the size of leader therefore increasing leader size decreases the number of drains required.
Calculate drains needed.
1 calculate the roof area to be drained.
300 x 500 150 000 sq.
Roof area is 300 x 500 ft.
The result is the number of drains needed.
This table is based on zurn s roof drain vertical requirement for horizontal roof areas at various rainfall rates table.
The pipe sizing is only one component.
1 in 25 4 mm 1 ft 305 mm 1 ft2 0 0929 m2 100 0 figure a101 1 example roof plan 4 a 101 2 solution.
Step by step sizing of zurn drains step 1.
The above sizing data is offered as a guide only.
The next step is to determine each roof area that will be served by a separate leader drain pipe scupper or downspout.
Determine the size of leader to be used.
2 estimate the roof drain outlet size you will likely use.
Sizing a roof water drain.
4 leader size is selected.
In a roof drainage system you have many components.
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.
To the table in figure 8 to determine the sizes of the various components of the conventional roof drainage system including roof drains vertical leaders and horizontal drainage piping.
Roof drain system and size the scuppers denoting the required head of water above the scupper for the structural engineer.
For the purposes of this appendix the following metric conversions are applicable.
4 roof drain 3 determine your building s location on the above map to determine the approximate rainfall as measured in inches per hour.
The sizing of the roof drainage system must consider all components.
Take the roof s total square footage and divide by the total square footage handled by one drain.
Roof area is 200 x 500 100 000 sq.
Rate of rainfall would require a 5 inch roof drain and leader as well as a 6 inch horizontal drainage line if a slope of 1 4.
Calculate total roof area.
The rain storm the flow of rainwater on the roof surface the ability of the roof drain to move the water from the roof to the piping the vertical piping the horizontal piping and the connection to the point.
