How many plumbing vent pipes can tie into the same two inch vent pipe going through roof ?

Hi Indy

That all depends... vents can connect into the vent prior to going out the roof, but you cannot exceed a certain number of fixture units and distance.

What fixtures are on the line and how far are the vents running from the farthest point to the point of exit through the roof?

Back to you..

MARK

Figure a typical bathroom group at 6 fixture units, a kitchen sink at 2 fixture units and a washer at 3FU you can put 10 fixture units on a 2 inch stack 3 stories or less with not over 2 water closets. The Standard Plumbintg Code also requires at least one three inch stack per single family dwelling. This stack usually services the kitchen. Answer Marks questions and let us know what you wish to accomplish. Regards, Tom

Total number of fixtures: 3 toilets, 2 bathtubs, 2 sinks, 1 shower cabinet.
How many feet: 35 feet from the farthest fixture to where the vent exits in the roof.
Thanks for your help,
Indy

How will your vents be configured? You're within code with a two inch vent for each bathroom group. Most bathroom groups are roughed in like this.
Toilet connects to sewer main or the stack vent. Lavatory connects to toilet drain and runs a vent off the top the stubout tee out the roof or revents back into a dry vent in the attic.. The toilet wet vents through the lavatory vent and the tub/shower connects to the lavatory drain and is wet vented by it. This is a normal rough in and is acceptable both by local and state codes and also The Standard Plumbing Code Book in 90 percent of the country. Check your local codes to make sure you're not in the excluded 10 percent.. The vent off the lavatory may be run out the roof or revented back into a dry vent in the attic or if you're reventing back into a fixtures dry vent you must make your connection at least 6 inches over that fixtures flood rim. Good luck and thank you for rating my answer. Tom