[B]Crew...[/B]

As part of the same bathroom gutting/remodeling undertaking (in my Step Son's recently purchased home) that prompted an inquiry from me over in Electrical Wiring...he finally got the floor disassembled right down to the joist bays (save for one small square of original flooring which supports the toilet.)

Today I peered into the floor under that toilet while visiting...in hopes of finding an easy solution to replacing the existing tub & sink drain lines...but it doesn't look so easy after all.

There is what looks to be a 1 - 1/2" aluminum or steel lateral (from the old vanity) running to the 4" the soil line (in the area of the toilet base); & an 1-1/2" copper lateral (from the old tub) running to same.

I was hoping to replace them both with PVC, but I've never run across the type of coupling that joins the drains to the soil line. There is a hole in the side (of the soil line) for each, of approximately 3 to 3-1/2" in diameter, with a metal funnel shaped collar piece emanating from the opening. The funnel shape tapers down to the diameter of the laterals, where they look to be brazed or soldered together. Not sure what exactly holds the base of the funnel collar inside the opening in the side of the soil line.

So I'm wondering...does anybody know what this is?

& even more importantly...once I remove everything...is there some sort of expanding PVC or hard rubber base that can be inserted in the holes in the soil line & secured...to accept the new 1-1/2" PVC drains?

Thanks very much,

[B]mark4man[/B]