This is going to be a mess I can see it all ready. Here it goes. I have planned out my basement and I am putting a full bathroom, washer and kitchen in. I am planning on cutting the vent through an existing upstairs closet (so I can hide it and later frame a plumbing chase around the pvc). The problem is that the toilet is about 9 feet away from the closet area that I intend to run the vent through. My questions is are:
1- How far away can the toilet be from the vent?
2- Do I have to use a 3" vent pipe?

Are there any other concerns that I need to be aware of?

Hi Swatcopsot80:

If you live in a typical single family home then the distance you are concerned about really isn't an issue. The more important issue is the distance between the toilet drain pipe and where you connect the 2" vent into that pipe.

If you are wet venting the toilet and tub/shower using a 2" lavatory drain (which becomes the 2" wet vent for the toilet and tub/shower and a 2" vent for itself) then you will need to connect the 3"x2" wye for the lavatory drain within 8 feet of the 3" toilet elbow. After the 2" picks up the lavatory drain the 2" turns into a vent that goes up and connects into another 2" vent or larger. You need to check to be sure that wet venting is allowed in your area to do this.

If wet venting isn't allowed then you will need to install a 3"x2" wye for a toilet vent (no fixtures on the 2" vent) within 8 feet of the toilet elbow. You will also need to run a 3"x2" wye for the tub/shower and the lavatory drain... these will need 1.5" vents that will need to connect into the 2" toilet vent at a minimum of 48" off the finish floor.

Kitchen sink gets 1.5" vent minimum. Washing machine gets 1.5" vent minimum. ALL vents connect into the 2" vent from bathroom and the 2" vent goes up and connects upstairs to 2" vent or larger.

You do not need a 3" vent.

Let us know as questions pop up...

MARK