I'm putting in a drain system. I've run a 3" vent pipe with a WC and lav on one side and a floor drain and tub/shower drain on the other, all within five feet, and draining into the main line. These all tee into the main sewer line, which runs horizontally under a slab. Will this be adequate venting, or will I need to tie into the main stack? I don't feel confident about venting knowledge. I read that the WC and all fixtures do not need to be re-vented if they are within five feet of the main stack and it is sized properly for the combined FU's.
Thanks much!
Thanks much!