The flow rate used for sizing the storm drainage piping shall be based on the maximum anticipated ponding on the roof.
Ipc roof drain sizing.
Using tools from the international plumbing code ipc it s not that hard.
To convert to an area for a 4 inch per hour rainfall to enter table 1108 1 do this.
The roof drain typically will not remove the water as fast as you may think.
Each vertical drain must carry 2 500 sq ft of roof area at 3 75 inches per hour of rainfall.
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.
Size horizontal storm drainage piping.
This wizard makes it easy to calculate the roof design area by providing various shape calculations and the calculation for vertical walls area per international plumbing code ipc.
Select number of roof drains and calculate the roof area sloped to each drain.
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.
50 000 4 400 11 36.
Following this logic it is possible that for roof drains 6 in.
Take the roof s total square footage and divide by the total square footage handled by one drain.
The flow through the primary system shall not be considered when locating and sizing secondary scuppers.
Determine 100 year 1 hour rainfall rate used for location of building.
The result is the number of drains needed.
Roof drain connected to a 6 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.
For example a 4 in.
Example roof plan 4 a 101 2 solution.
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.
Scuppers shall not have an opening dimension of less than 4 inches.
Sizing vertical roof drains with 2018 international plumbing code.
When scuppers are used for secondary emergency overflow roof drainage the quantity size location and inlet elevation of the scuppers shall be sized to prevent the depth of ponding water from exceeding that for which the roof was designed as determined by section 1611 1.
2 500 4 x 3 75 2 344 sq ft.
Ipc provides four steps to size the roof drains on a building.
Scupper openings shall be not less than 4 inches 102 mm in height and have a width that is equal to or greater than the circumference of a roof drain sized for the same roof area.
Smacna s new downspout and gutter sizing calculator enables the user to manually enter the design area of the roof or use the design area wizard for the calculation.
