Most plumbing codes allow three bathroom sets on 3"
The fourth bathroom set requires 4"
Hi all. I have a new 3" PVC horizonal soil line running under a new bathroom. The soil line runs 13 Ft and long sweeps down to basment 4" line and wyes in. My question can I Wye in to that 3" line along the way and pick up my bathroom fixtures as I go. 1-toilet, 1-shower, 1- lav, 1- shower. Each and every fixture will have its own vent with in allowable distance. The vents will tie together above the highest fixture and get increased to 3" before going out to roof.