How close and what size must a toilet vent be to the commode?

How close and what size must a toilet vent be to the commode?

Your vent size will be two inches. How far away from the toilet will depend on two things. The code you fall under and the size of the drain line.( Both of which you failed to provide.) Generally speaking 10 to12 feet on a 4" drain and 6 'to 10' on a three inch drain line. All depending on where you live, the code your area falls under and any local codes that may prevail. Good luck, Tom

Hi speedball 1,
Thanks for taking time to help. I have been away from the house a few days. That is why I did not hollar back earlier. The drain line is a 3". I was hoping to use a wet vent sertving the lav which is about 3' downstream of the toilet.

Hi Inspectordude...

I'll pop in here because I have good picture of what you are doing. Since the drain line will be 3" you will want to install a 3"x2" wye within 8 feet of the toilet to pick up the lavatory...so if sink is only 3 feet from the toilet you are all set.

The 2" lavatory drain will run to about 18-20" off finish floor to the center of the drain for a lavatory (take off with a 2" x 1.5" sanitary tee fitting). The 2" drain line continues as a 2" vent until it can connect into another vent that is 2" or larger. This sink vent will act as a wet vent for the toilet just as you suggested.

Let us know if you need more info...

MARK