I had a question if some one could help answer. Say if you had a toilet with a 3 inch line going directly back into the wall with a tee that is the main stack for the bathroom group with a 3 inch vent. Could you run a lav. Drain into the 3 inch stack vent above the toilet and use the vent as a wet vent. Or would the fixtures have to be a maximin of 2 dfu each. It is under the UPC.

Any help much appreciated.

Thanks

Welcome

If you use the vertical stack as a waste line for the sink then you actually have the sink WET VENTING the toilet... ;)

This is acceptable almost everywhere that I know of... see picture.

Let me know if you have questions...

MARK

What part of country will this project be built ?

The UPC 908.1 say only one and two fixture unit fixtures not to exceed four. The toilet is three dfu. That why I am not sure.

Thanks

If I were you I would call your Building Department and ask your Plumbing Inspector what exactly is required.

I work under UPC in combination with Local Codes. In this situation, I would not be allowed to connect to 3" stack by my Inspector. Also, I would have to run dedicated vent through the roof - or possibly connect to the 3" stack in the attic.