Roof Drain Sizing Method

Determine 100 year 1 hour rainfall rate used for location of building.

Roof drain sizing method.

Roof drain connected to a 6 in. The following example gives one method of sizing the primary drain system and sizing the scuppers in the parapet walls. Size horizontal storm drainage piping. Ipc provides four steps to size the roof drains on a building.

6 9 can be used as printed. Following this logic it is possible that for roof drains 6 in. Select number of roof drains and calculate the roof area sloped to each drain. Strategies for stormwater storm drainage system research control flow roof drains pub rain collapse roof water drain types and sizing roof drain sizing method library builderfour s to sizing roof drains c1sroof drainage 2016 05 11 plumbing mechanicalroof drain sizing method library buildernew sizing method for roof drainage aims to clear up confusionroof drainage 2016.

1 rate of precipitation. Learning siphonic roof drainage rainwater downpipes and roof gutters how to calculate drainage gravity system roof drainage calculator surveyor land surveying four s to sizing roof drains c1scalculating roof areafour s to sizing roof drains c1sroof drain sizing method library builderhow to calculate drainagegutter and downpipe systems rainwater design system selectionwhat do you know about. When sizing roof drains the limiting factor for the amount of water each drain will carry away is the size of leader therefore increasing. For larger roof drains the pipe may be smaller such as a 10 in.

3 size of leader required. And 4 area handled by each drain. Take the roof s total square footage and divide by the total square footage handled by one drain. 2 total area of roof.

The result is the number of drains needed. 2 500 4 x 3 75 2 344 sq ft. A minimum 4 inch vertical drain is required. Or less in diameter the piping will be larger in diameter than the roof drain.

Or 12 drains required. Each vertical drain must carry 2 500 sq ft of roof area at 3 75 inches per hour of rainfall. Appendix a roof drain sizing method appendix a is for informational purposes only a101 sizing example the following example gives one method of sizing the primary drain system and sizing the scuppers in the parapet walls. 50 000 4 400 11 36.

For example a 4 in. Zurn makes it easy to size roof drains. This method converts the roof area to an equivalent roof area for a 4 inch rate of rainfall so that table 1108 1 and table 1108 2 can be used as printed. This method converts the roof area to an equivalent roof area for a 4 inch rate of rainfall so that fig.

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