# Does a bathroom sink need a vent pipe?

## Does a bathroom sink need a vent pipe?

A sink needs a vent because the pressure put on the drain pipe when water flows down the drain pipe needs to equalize. The air needs to escape the drain pipe in order for the sink to vent.

## Where is vent pipe for bathroom sink?

In new construction, the simplest way to vent a bathroom group is usually to install a single vertical vent pipe behind the bathroom sink. This works as long as all the plumbing fixtures connect to the main drain line in the floor within 6 to 10 lineal feet of the sink drain.

How far away can a vent be from a sink?

Install the vent between the sink P-trap and the point where the waste line leading from the trap drops to the main sewer. If the waste line has a diameter of 1 1/4 inches, the vent can be no farther than 2 1/2 feet from the trap. If the waste line is 1 1/2 inches, this critical distance is 3 1/2 feet.

How far can a vent be from a sink?

### How far should a vent be from a trap?

P3105. 1 Distance of Trap From Vent

SIZE OF TRAP (inches) SLOPE (inch per foot) DISTANCE FROM TRAP (feet)
11/2 1/4 6
2 1/4 8
3 1/8 12
4 1/8 16

### How far can a sink be from a vent stack?

There is a vent between the sink P-trap and the point where the waste line goes to the main sewer. The vent can’t be more than 2 1/2 feet from the trap if the waste line has a diameter of 1 1/2 inches. The critical distance is 3 1/2 feet if the waste line is 1 1/2 inches.

How far can a bathroom sink be from a vent stack?

Do bathroom vents need to be vented outside?

Note that the bathroom vent fan must always exhaust to the outdoors; never allow the duct to simply blow into an attic, crawlspace or other enclosed area.

#### How far can a vent be from a sink drain?

If you have 1 ¼-inch pipe, the horizontal distance of the vent should not be more than 30 inches. For a 1 ½-inc pipe the vent should be 42 inches away at the most while a 2-inch pipe must have a maximum distance of 5 feet.