Toilet Drain Pipe Size

The drain pipe in your toilet carries waste away into the home s main drain line.

Toilet drain pipe size.

The toilet flange is the fitting that attaches the toilet to the drain line. A standard rule of thumb is that sewer pipes leading away from a toilet are 3 inches in diameter. The fourth size is 3 inch drain pipe that can be connected to 20 units in horizontal stack and 30 units in vertical stack. Water closet s flushing 1 6 gallons or less are rated at 3 dfus drainage fixture units.

Regardless of your plumbing code the minimum drain size for a toilet is 3 inches. Compare the fixture to the minimum sizes of drainage pipe by fixture table. For instance the minimum pipe diameter for a washing machine drain is pipe with a 1 1 2 inch diameter. The toilet s drain size.

The main sewer pipe leading to the septic tank or public sewer is usually 4 inches. Main toilet drain or stack 4 inch pvc or iron pipe. The bottom is designed to fit on 3 inch schedule 40 pipe used in most homes as standard sized drain pipe. This is the home s main drain line the drain pipe connects to this pipe.

This is also the size of the closet bend pipe in most cases. Sewer drains from laundry sinks or washing machines are 2 inches in diameter and those from sinks in the kitchen bathroom or powder room generally use a 1 5 inch pipe. The drain pipe connects to the flange which mounts the toilet itself and this flange is usually built to connect to 3 inch schedule 40. The top side of the flange which connects to the toilet is 4 inches in diameter while the bottom diameter of the pipe is 3 inches.

The last size is 4 inch drain pipe that can be connected to 160 units in horizontal stack and 240 units in vertical stack. Most homes use a 4 inch drain pipe only high rises supporting more than 5oo appliances use a larger pipe size. Slope this pipe at 1 8 inch per foot grade to the main drain stack. The diameter of the waste outlet for the toilet may not match the diameter of the drain pipe the toilet may be 4.

This is the minimum size to use for building sewer or drain pipe that is connected to the toilet.