How To Size Roof Drains 2015 Ipc

For multiple walls use 50 percent of the maximum projected area of all walls.

How to size roof drains 2015 ipc.

The flow rate used for sizing the storm. Size horizontal storm drainage piping. Four steps to sizing roof drains. 2 500 4 x 3 75 2 344 sq ft.

2015 ipc code states. For example a 4 in. Following this logic it is possible that for roof drains 6 in. Or less in diameter the piping will be larger in diameter than the roof drain.

A minimum 4 inch vertical drain is required. To convert to an area for a 4 inch per hour rainfall to enter table 1108 1 do this. For single roof drains for single vertical walls affecting the collection area of a roof drain add 50 percent of the side area to the total for calculating the flow rate. Determine 100 year 1 hour rainfall rate used for location of building.

Section 1111 subsoil drains 1111 1 subsoil drains. Roof drain connected to an 8 in. Section 1105 roof drains 1105 2 roof drain flow rate. For single curved vertical walls use 50 percent of the maximum projected area.

For larger roof drains the pipe may be smaller such as a 10 in. The published roof drain flow rate based on the head of water above the roof drain shall be used to size the storm drain drainage system in accordance with section 1106. Roof drain connected to a 6 in. Each vertical drain must carry 2 500 sq ft of roof area at 3 75 inches per hour of rainfall.

Enter table 1108 1 until you find a diameter pipe that will carry 2 344 sq ft.