Maximum pipe flow.
Roof drainage design guide.
The greater the slope the less water build up and thus roof load.
Volume of expected rainfall.
Type of roof construction 2.
Structural design of the roof and roof load.
Determine leader or pipe size.
Safety load requirement 8.
Ipc provides four steps to size the roof drains on a building.
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 of discharge.
Size vertical storm drainage piping.
To select the proper roof drain the following information must be known.
The sizing of the roof drainage system must consider all components.
The location and degree to which.
Step by step instructions step 1.
When selecting a roof drain note.
In either case the discharge shall be located so that it is readily visible by building occupants.
Slope of the roof.
Rainfall intensity roof catchment area gutter size capacity gutter fall gutter outlets sumps rain heads nozzles downpipe size quantity and placement overflow consideration material.
Inspect the roof surface and roof drains on a regular schedule to find and clear away any debris clogging the drains.
2 3 4 5 6 and 8 in.
From there consider the following.
2 3 4 5 6.
Pleasing dome shape with a low profile and adequate free drainage area corrosion resisting dome material effective debris protection overflow drainage to allow drainage during debris build up gravel stop positive flashing clamp seepage control channels.
Calculate the total roof area by multiplying its length by width.
Select number of roof drains and calculate the roof area sloped to each drain.
Properly designed roof drain must have the following features.
In the design and detailing of a roof drainage system consideration must be given to a range of factors such as.
Secondary drainage shall be provided through the use of sidewall scuppers or internal roof drains.
Secondary or emergency roof drainage is required wherever the buildup of water is detrimental to the roof structure.
Size horizontal storm drainage piping.
Developing the design criteria for a roof drainage plan that will perform with the roofing system to drain the roof is critical priorto the bid process and roof system installation.
First and foremost be sure to comply with all local plumbing codes.
Design assistance services are offered as a courtesy to the roofing design professional and contractors to ensure the project s success.
Inspect the current roof drain s and the drain line through the building for leaks and assure that the materials are.
Location of drains 5.
Desired rate of drainage 6.
Calculate total roof area.
