Can I have the same vent from the sink (I have a T that woks as drain and vent, connected to the 3" drain) for the toilet and shower? The vent pipe is 2", the toiler and shower are less than 5 ft from the sink vent. Because the sink vent pipe is used as drain also I am not sure that I can used as vent for the rest even that the critical distance is not more than 5 ft that is OK for 2" pipe. I don't want to have more concrete blocks in the basement.

Hi Monoloca

You are asking if you can WET VENT a toilet and a shower using the 2" sink drain and vent. The answer to that will depend on your state/local plumbing codes, but yes, there are many states that allow wet venting of an entire bathroom group...;)

Here are just a couple of examples of how wet venting rules are applied to 1/2 bath (toilet and sink only) and an entire bathroom group (toilet, sink, tub or shower)...see images. Let me know if you have questions, OK?

Mark

Thank you very much! My is like the second pic. I wasn't sure I can use the wet vent from the sink for the other two.