Roof Drainage Design Guide

Safety load requirement 8.

Roof drainage design guide.

Inspect the current roof drain s and the drain line through the building for leaks and assure that the materials are. Maximum pipe flow. Desired rate of drainage 6. Properly designed roof drain must have the following features.

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. The location and degree to which. 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. Secondary or emergency roof drainage is required wherever the buildup of water is detrimental to the roof structure.

In the design and detailing of a roof drainage system consideration must be given to a range of factors such as. Calculate total roof area. Determine leader or pipe size. Inspect the roof surface and roof drains on a regular schedule to find and clear away any debris clogging the drains.

Determine 100 year 1 hour rainfall rate used for location of building. The greater the slope the less water build up and thus roof load. Location of drains 5. Rainfall intensity roof catchment area gutter size capacity gutter fall gutter outlets sumps rain heads nozzles downpipe size quantity and placement overflow consideration material.

Calculate the total roof area by multiplying its length by width. Roofs inevitably serve as temporary rainwater reservoirs. In either case the discharge shall be located so that it is readily visible by building occupants. Roof load requirement 7.

Ipc provides four steps to size the roof drains on a building. Select number of roof drains and calculate the roof area sloped to each drain. 2 3 4 5 6 and 8 in. Size vertical storm drainage piping.

The sizing of the roof drainage system must consider all components. Type of roof construction 2. To select the proper roof drain the following information must be known. Size horizontal storm drainage piping.

Slope of the roof. Step by step instructions step 1. From there consider the following. First and foremost be sure to comply with all local plumbing codes.

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. 2 3 4 5 6. Structural design of the roof and roof load. Volume of expected rainfall.