Roof Slope Drainage

The following diagram lays out the different terms that are used in the calculator.

Roof slope drainage. 2 see sentence 9 26 3 1 3. The slope of a roof or pitch is determined by how many inches the roof rises over 1 foot or 12 inches. To put it in perspective the angle of this slope would be around 30 degrees. Structurally sloped roof decks can be beneficial in that they can create positive drainage flow.

First figure out the diameter of the pipe you are working with. But with four way structurally sloped roof decks the drain is not necessarily at the low point of the roof. How to use the calculator. We were able to make new crickets to the existing roof membrane providing positive water flow to the drains.

Drain pipe slope calculator. However minimum slope for a flat roof by building code here is 2. Notes to table 9 26 3 1. This means that the rise of the slope goes up or down 8 inches for every 12 inches.

Roof drains in four way slope roof decks. Then we were able to correct the owner s ponding water concerns. Despite the name all flat roofs need to be slightly angled in some direction. This is necessary for allowing water to run off of the epdm membrane surface and towards an appropriate drainage system but this slope doesn t need to be extremely steep and when covering a large property the angle of the flat roof can be near invisible to the naked eye.

The roof pitch or slope factors for roof pitch are used to multiply or increase the rainfall rate if we are draining a sloped roof the roof drain or gutter or drain piping or downspout leader size diameter other size constraints e g. Along with the benefits of a flat roof come unique challenges. Your building and location can help determine which drain will fit your roof needs. Roof slope created a simple and great fix to a project were crickets were missed and ponding water became an issue for an owner.

1 see sentence 9 26 3 1 2. For household sinks the drain pipe diameter is often either 1 5 or 2. The most critical of these issues is the flat roof drainage systems. No roof should be entirely flat but rather should slope either toward the perimeter or toward an interior drainage system.

3 profiled metal roof cladding systems specifically designed for low slope applications are. 2 asphalt and gravel or coal tar and gravel roofs may be constructed with lower slopes than required in sentence 1 when effective drainage is provided by roof drains located at the lowest points on the roofs. An example for a steep sloped roof is 8 12. Of course the best designed flat roof has the correct amount of pitch to drain the water off naturally.

After 48 hours following a rain any roof which still has standing water is known as a ponding roof.