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joeusa 01-24-2011 09:07 AM

PVC into cast iron soil stack? (pics)
This is DIY bathroom re-do job. The drain pipe from the shower has rusted and broke off at the "y" branch arrow "B". It will be replaced with PVC. The yellow line is the bathroom sink drain...and I've cut that pipe off at the yellow line. It is going to be replaced with PVC as well. I want to remove the Y-branch.

I figure that I'll use one of these rubber couplers slipped around the hub at "A" to adapt to the new PVC from thre sink and shower.

So here is the problem. I cannot get the "Y" branch out of the hub at "A". I do not have any experience with this hardware...but I figured it would wiggle out with some muscle. I don't have enough muscle to do it.....even with the mutha-of-all-breaker-bars on the end of a pipe won't budge. It's a tight fit under the house and not much room to work.



kok328 01-24-2011 03:28 PM

Back in the day, these were assembled with rope (Oakem(sp)?) and lead. They literally packed/hammered rope into the joint and then fill them with lead.
Knowing this, you'll need some fire to put on the joint and maybe a hammer and chisel to dig out the joint. This is cast iron and prone to crack if not handled properly. Another approach I've taken was to drill out around the pipe and then break it with a hammer and remove the pieces.
IMO, your best bet is to tap onto the stub remaining from the bathroom sink drain.
Good Luck.

Redwood 01-24-2011 04:39 PM

I would pick the lead and oakum out of the joint the wye goes into then use a Ty-Seal to put in the new PVC in place...

JohnchambersJr 01-25-2011 12:40 AM

Cast-iron transition
The previous repies were the best way to go. Make sure you use a tye-seal and not any of the couplings that you pictured. I concure with the answer about removing the original joint; do not stress and crack it! Be patient and for you I would recommend drilling it out. You may not be aware that a shower drain needs to be 2" by code. I also question the other line you cut off at "B". It looks in the picture to be 2." Are you sure that it is just the bathroom sink"lav"? Does something else such as a kitchen sink tie in upstream? Lav lines are usually 1 1/2" inch. If you don't replace all of that horizontal pipe back as far as you can, you will be doing it again in the future. If you do elect to do these horizontal lines, you can use the couplings you showed, provided they are the right size and application, to attach to any verticles for now. The verticles are usually in much better shape. Most couplings are specific to the type of pipe as the wall thickness is different. John

joeusa 01-25-2011 07:38 AM

Great input guys! Thank you!

OK...I think I got...I'm going to crawl back under the floor and try to drill aroung the wye to remove as much of the lead and rope packing as possible....then pick and chisel...then keep trying to work it loose.

I don't think I want to get in there with a torch...I'm guessing that it will take a ton of heat to loosen things up...and there will be lot's of smoke and smell. That won't fly very well with the wifey.

Thanks for the picture Redwood! That is very helpful!

2" for shower drain...Got it! (thank you..I was on the way for 1-1/2")

Yep the top horizontal run is just sink drain. I've removed it all...up to the dry vent area in the wall. The vent stack for the sink is very solid and will be kept...but the wet sections had to be cut out and will be replaced with PVC.

The bath re-do is a complete gut job to bare studs and ceiling there's good access in the walls right now.

Again, thank you kindly for these tips...great stuff!


Redwood 01-25-2011 11:58 AM

Just so you know there are several different types of cast iron pipe and the hub sizes are different so you will need to get the right size ty-seal.

When you have the right one it goes together with a little difficulty and lubrication...

When you have the wrong one it's like an elephant making love to a gopher...
It's just a question of which one is the male and which one is the female....

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