Can I tie a basement vent into drain pipe of upstairs sink?
My stand pipe is galvanized, but the sink drain from upstairs sink is PVC. Can I tie the vent pipe into the existing drain (ie pipe in ceiling of basement) and make it a wet vent?
Is this legitimate, as long as the total horizontal remains under 5' for a 2" pipe?
Note: The pvc goes into the galvanized stand pipe, and that is the only vent pipe. Upstairs bathroom doesn't have separate vent pipes.
Basically, This would keep me from having to crack the galvanized pipe to add in another wye to fit the vent. There aren't walls upstairs that line up to put another vent pipe up.
Connect above flood plane?
Connecting above the flood plane, do you mean above the trap of the sink?
All of the old pipes in this house are using the stand pipe as their vent, and the critical lengths don't match with todays regulations, but I can understand they did when built. So now I'm trying to figure out how to tie into the stand pipe without having to crack the galvanized pipe.
There is a 4-inch cross pipe that connects both upstairs toilets (1 1/2 bath) to the stand pipe. On one side of that cross is a 1 1/2" input that has a wye connection right away. One of those connections goes to the shower (6' run), and the other takes both sinks (5' is the longer of the 2 runs).
Can I break one of those open and put in another wye to tie into the pipe, or do I need to vent clear up separate?