Floor Drain Pipe Pitch

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

Floor drain pipe pitch.

Standard horizontal drainage pipe slope. Expressing slope in. A pipe that doesn t slope enough won t drain. A pipe with a very extreme slope of 45 degrees or more is considered vertical.

Pipe slope and pitch terminology plumbers and building authorities express slope in either percent grade or inches per 1 foot unit. Laying a drainage pipe for plumbing is a job for professionals. Larger lines such as 8 pipe actually require less pitch due to the larger circumference of the pipe. 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. The term slope is also frequently used and has the same meaning as pitch. Drainage pipes are usually run at the minimum allowable slope so that ceilings can be kept as high as possible. Note that i said the drain pipe must be sloped rather than the french drain.

How to use the calculator. The maximum slope for efficient drainage is usually a drop of 1 2 inch per 1 foot of horizontal distance. With the siphon principle in mind i first make sure that any drain less than 3 inches in diameter has at least a 1 4 inch slope 1 8 inch slope for 3 inch diameter and greater and then i simply measure from the floor assuming that it is level to the bottom of the drain at the trap connection where the trap weir is located. A pipe that slopes too much drains water but not solids.

If you re installing a drain pipe here s an easy way to figure out the slope for a drain pipe. Lay the pipe with enough slope to drain to a non perforated pipe that carries the collected water to daylight to a drywell to a storm sewer if approved by the local municipality or to a sump pump that will. Install drain pipe to sit outside of not on top of the footings and below the bottom of the concrete slab or crawlspace floor. Calculating the slope of your drain pipe is easy.

It is generally accepted that 1 4 per foot of pipe run is the minimum for proper pitch on a sewer line. Don t bite off more than you can chew. Drain pipe slope calculator. 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.

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. All of your drain pipe with one exception must slope slightly downhill.