Standard Shower Drain Pipe Size

Rough in plumbing should be calculated for a 1 1 2 inch pipe.

Standard shower drain pipe size. However most of the bathroom sinks use 1 inch drain pipe. As a result most building codes will require this size drain pipe for every shower. A standard modern bathtub drain is 1 1 2 inches in diameter the width straight across the middle.

Shower only units require a 2 inch drain and p trap. This size is the minimum size that is allowed which means that you cannot install a trap with a smaller diameter or the trap is not within code. Every state may have different code on plumbing and it may affect the required size of the bathroom sink pipe.

Also the drain pipe that the trap is connected to must also be 2 inches to comply with the code. A vent pipe will need. This size is precisely the diameter of the pipe instead of the length.

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. Most shower pans or trays are going to be fitted with a two inch pipe. The usual size for a shower drain trap is 2 inches which is the diameter of the trap.

And if you keep a supply of size adaptable shower drains on hand such as the oatey 2 inch or 3 inch pvc shower drain available from supplyhouse the size discrepancy won t slow you down at. The main sewer pipe leading to the septic tank or public sewer is usually 4 inches. The drain requires a horizontal drop or angle of fall of one quarter inch per linear foot.

A 2 inch drain pipe is better. Keep in mind that shower drain assemblies are generally made to fit a 2 inch drainpipe not the 1 1 2 inch pipe usually found on tubs. A standard rule of thumb is that sewer pipes leading away from a toilet are 3 inches in diameter.