Ibc Roof Drain Sizing

The international code council icc is a non profit organization dedicated to developing model codes and standards used in the design build and compliance process.

Ibc roof drain sizing.

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. P 1503 4 1 secondary emergency overflow drains or scuppers. 1 inch 25 4 mm 1 inch per foot 83 3 mm m. 2 500 4 x 3 75 2 344 sq ft.

The result is a roof collapse. P 1503 4 roof drainage. Take the roof s total square footage and divide by the total square footage handled by one drain. The international codes i codes are the widely accepted comprehensive set of model codes used in the us and abroad to help ensure the engineering of safe sustainable affordable and resilient structures.

Following this logic it is possible that for roof drains 6 in. Vertical and horizontal storm drain piping shall be sized based on the flow rate through the roof drain. Each 4 drain size in a 6 hourly rainfall area will accommodate drainage of 3 070 sq. 1106 2 size of storm drain piping.

In total square footage covered per drain 23 14 2 880 1 920 1 440 1 150 960 720 575 480 410 360. Example roof plan 4 a 101 2 solution. The flow rate used for sizing the storm drainage piping shall be based on the maximum anticipated ponding on the roof. The minimum size of any building drain serving a water closet shall be 3 inches.

For example a 4 in. Or 12 drains required. Design and installation of roof drainage systems shall comply with section 1503 of this code and sections 1106 and 1108 as applicable of the international plumbing code. The flow rate in storm drain piping shall not exceed that specified in table 1106 2.

The result is the number of drains needed. Roof drain connected to a 6 in. The roof drain typically will not remove the water as fast as you may think. Or less in diameter the piping will be larger in diameter than the roof drain.

From figure 1108 4 the 100 year 60 minute precipitation is 3 75 inches per hour. The maximum number of drainage fixture units connected to a given size of horizontal branch or vertical soil or waste stack shall be determined using table 710 1 2. To convert to an area for a 4 inch per hour rainfall to enter table 1108 1 do this. Select a reference of a roof drain size with hourly rainfall together with the roof area square footage you have estimated and then determine from the chart below how many roof drains you require.

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.