Roof Drain Pipe Slope

Larger lines such as 8 pipe actually require less pitch due to the larger circumference of the pipe.

Roof drain pipe slope.

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. An accurate calculation is essential for properly functioning plumbing. The standard slope is anywhere from inch to 3 inches per foot. Slope of drain and waste pipes drainpipe sloping requirements vary according to the pipe s diameter.

Tips on calculating drain pipe slopes use the longest level possible for your application for the best accuracy when the bubble on a level is about 1 4 of the way past the line it is about a 1 4 slope. In general plumbing codes require pipes less than 3 inches in diameter to slope a 1 4 inch per foot of run. It is generally accepted that 1 4 per foot of pipe run is the minimum for proper pitch on a sewer line. Cleanouts in draining systems cleanouts provides access to the sewer for rodding.

All of your drain pipe with one exception must slope slightly downhill. According to the chart for 1 8 slope per 12 of pipe for 5 000 square feet of roof area with a 6 per hour of rainfall the required pipe size is 8. Sanitary drainage systems the purpose of a sanitary drainage system is to remove effluent discharged from plumbing fixtures and other equipment. To size the vertical roof drain for the same parameters 5 000 square feet of room area and 6 per hour of rain consult table 1106 2 figure 3.

Drain waste and vent pipe hanger spacing support of drain waste and vent dwv pipes. Usually 1 8 per foot is plenty for drainage this is the same as the commonly recommended 1 slope. But there are other issues concerning pitch to keep in mind. Note that i said the drain pipe must be sloped rather than the french drain.

Same logic with 1 8 slope 1 16 slope etc. Smaller pipes are more likely to experience blockages than larger pipes and therefore require a steeper slope. The flat roof must have sufficient slope to allow water to flow towards the roof outlets. Ss525 2006 code of practice for drainage of roofs.

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. The term slope is also frequently used and has the same meaning as pitch. Pipes must slope slightly downhill to drain properly.