How To Size Roof Leader Collection Pipe Size

For the purposes of this appendix the following metric conversions are applicable.

How to size roof leader collection pipe size.

4 leader size is selected. 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. 300 x 500 150 000 sq.

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 next step is to determine each roof area that will be served by a separate leader drain pipe scupper or downspout. 1 calculate the roof area to be drained. 2 estimate the roof drain outlet size you will likely use.

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. The result is the number of drains needed. The first step in sizing a roof drain is to calculate the surface area of the roof that the drains will be covering as well as the average hourly rainfall rate at the building location. Sizing a roof water drain.

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. 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. That is what is wrong. The sizing of the roof drainage system must consider all components.

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. Calculate drains needed. Roof area is 300 x 500 ft. In a roof drainage system you have many components.

The above sizing data is offered as a guide only. In sizing roof drains and storm drainage piping one half of the area of any vertical wall that diverts rainwater to the roof shall be added to the projected roof area for inclusion in calculating the required size of vertical conductors leaders and horizontal storm drainage piping. Take the roof s total square footage and divide by the total square footage handled by one drain. Step by step sizing of zurn drains step 1.

The pipe sizing is only one component. Determine the size of leader to be used. Calculate total roof area. This table is based on zurn s roof drain vertical requirement for horizontal roof areas at various rainfall rates table.

4 roof drain 3 determine your building s location on the above map to determine the approximate rainfall as measured in inches per hour.