DIY Bathroom Addition Vent and Drain Questions

Does every bathroom fixture need a vent?

No bathroom plumbing system is complete without ventilation. When you flush the commode or drain the tub, wastewater pushes the existing air in the pipes and can form a water lock if additional air does alleviate the vacuum effect.

Can a shower and toilet share a vent?

Wet vents are typically used when plumbing a bathroom group. So yes the shower can also be vented by the wet vent along with the toilet. There is one major stipulation when wet venting multiple fixtures when a toilet is one of them: the toilet must be the last fixture connected to the wet vent.

Can two drains use the same vent?

Common vent



This very simple concept allows two traps to be vented by the same vent. The two traps and their fixture drains can be either at the same level or at different levels, provided that they are on the same floor.

How far can vent be from shower drain?

The connection between the fixture drain and the horizontal drain and vent pipe is the only vertical pipe of a combination drain and vent system. 8 feet is the maximum vertical distance.

How far away can a vent be from a toilet?

6 feet

According to the UPC, the distance between your trap and the vent should be no more than 6 feet. In other words, for the vent to work properly, it needs to feed into the drain line within 6 feet of the trapways that connect to it.

Do plumbing vents have to go through the roof?

It does not have to go through the roof. From the plumbing code (I have the 2003 edition), P3103: It must not be less than 4 feet directly beneath a door, openable window or other air intake of the building or adjacent building.

Can a sink and shower share a vent?

You can put the sink drain into the shower drain. 2. If the vent is less than 5 feet from the other fixture, they can share it.

Does vent go before or after trap?

The simple answer is if your trap from the fixture cannot see the vent then it is installed wrong. We must always keep the vent connection above the trap weir to prevent siphoning and keep proper pressures on both side of the trap.

How many plumbing vents can be tied together?

You can usually tie up to eight fixtures to a single stack, but local codes differ, so it’s a good idea to check.

How do you run a vent and drain line?

Quote from the video:
Quote from Youtube video: In order for the waste and water in the pipe to flow freely. You have to have air and that's when the vent plays a big part a vent is just no more than a.

Can you drain into a vent stack?

A wet vent may be allowed if the fixture is close enough to the stack. A tub that is close to a stack may have a drain that empties into a pipe that serves as a vent.

Can 2 toilets share a vent?

The waste lines can usually be tied into the same stack if the house has more than one toilet. They may need their own stack if they are on opposite sides. Two vent openings on the roof are needed since the stacks must be vented.

How many drain vents do I need?

At least one main vent stack is required for every building that has plumbing when connecting separately to the sewer for the building or its septic tank. The stack has to run the most direct route through open air or be ventilated to extend to open air.

Can sink and toilet shared vent?

A general rule is that you can only vent 2 fixtures on a toilet wet vent. The sink drain has a toilet vent through it. The toilet drain should be 3′′, the sink drain is 1.5′′, the shared sink drain/toilet vent area should be 2′′, and the vent going up should be 1.5′′.

How big does a vent stack need to be?

The minimum required diameter of stack vents and vent stacks shall be determined from the developed length and the total of drainage fixture units connected thereto in accordance with Table 916.1, but in no case shall the diameter be less than one-half the diameter of the drain served or less than 1 1/2 inches (38 mm).

What is the difference between a stack vent and a vent stack?

A vent stack is a vertical pipe that is only used for venting, and runs upward from the drain piping to the open air outside the home. Vent stacks are primary vents and accept connections from other vents in a plumbing system. A stack vent is used for both drainage and venting.

How far should a vent be from a trap?

P3105. 1 Distance of Trap From Vent