Roof Drain Pipe Slope

The calculations below are meant for drainage from flat roofs where water are expected to spread over the entire flat roof during rain.

Roof drain pipe slope.

I downloaded installed and tried out harmer drainage s free roof drainage calculator for a flat roof choosing a roof drain product line which has implications of drain pipe diameter and thus capacity geographic area the tool can plug in rainfall rates for the u k and i used an assumed a roof area of 10x10m 100 m2. Sanitary drainage systems the purpose of a sanitary drainage system is to remove effluent discharged from plumbing fixtures and other equipment. Calculating the slope of your drain pipe is easy. A slope of less than 1 4 inch per foot will cause constant drain clogs and a slope of more than three inches will allow the water to drain without the solids.

Drain pipe slope calculator. But there are other issues concerning pitch to keep in mind. The term slope is also frequently used and has the same meaning as pitch. This drain pipe slope calculator will calculate the slope and total drop fall of a drainage pipe over a specified length of pipe.

The following diagram lays out the different terms that are used in the calculator. The best type for the application depends on several factors such as the size and slope of the roof the desired appearance and how much regular maintenance the drain system might need. It is generally accepted that 1 4 per foot of pipe run is the minimum for proper pitch on a sewer line. The secondary roof drains shall connect to a piping system in accordance with section 1101 12 2 2 1 or section 1101 12 2 2 2.

Cleanouts in draining systems cleanouts provides access to the sewer for rodding. Usually 1 8 per foot is plenty for drainage this is the same as the commonly recommended 1 slope. Roof drains for flat or low slope roofs come in a few standard types. Drain waste and vent pipe hanger spacing support of drain waste and vent dwv pipes.

According to plumbing code drain pipe has to be sloped a minimum of 1 4 inch per foot and a maximum of three inches per foot or vertical. How to use the calculator. The maximum height of the roof drains shall be a height to prevent the depth of ponding water from exceeding that for which the roof was designed as determined by section 1101 12 1. While vent piping generally runs straight to the building s roof in a vertical path drain and waste branch pipes must slope toward main drainpipes which slope toward main drain outlets.

The roof drainage outlets and rainwater downpipes are calculated based on the design principles for gravity drainage systems established in ss525 2006 code of practice for drainage of roofs. All of your drain pipe with one exception must slope slightly downhill.