I looked at a house "bathroom" for a friend today. He wanted an opinion
and unfortunately, I didn't have one, so I'll ask youse.
There is a bathroom sink with its own P-trap under the sink. The sink's
drain (ABS - in the basement below) runs into the drain (ABS) from the
shower, also in the basement below. This drain has a P-trap for the
shower and then the drain exits the basement.
Is it a problem having the drain for the sink have, essentially 2 P
traps, its own and also the P-trap for the shower downstream?
Also, the vent stack (I forgot to get the size of this) for the sink is
the same one for the shower and it's downstream of the shower's P-trap.
He says he hasn't had any problems with flow, though the shower and sink
aren't used every day. All of the drain lines in the basement are 2" ABS
It's an older house and I assume the work was done by a previous