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.