When to say when on replacing old drain pipes

I have an older (1940s) house and I've done a bunch of work on the supply - replaced all the old galvanized from the main with pex. I've also re-routed some old galvanized DWV with ABS, replaced about 3/4 of the drains. BUT...

Now I'm looking at the stack and I've got some issues. It's Cast iron, with the exception of a lead bend for the toilet, which is also connected to a now-abandoned drum trap that used to service the tub. The thing is that the lead drum trap has a lead pipe that goes up into the wall and ties in to the stack, along with a galvanized vent for a basement utility sink.

On the bottom end of the stack, I would like to add a toilet and sink in the basement, but I've chipped the concrete and found that I've basically only got fittings underground on the inside of the foundation; no pipe to fernco onto. Outside the foundation is my neighbor's driveway that would be a lot of work to chip out and dig. I've read about people putting donuts into old cast fittings, but the do-it-yourself plumbing specialty store here told me that "might" work - or it "might" crack the hub and all of the plumbing in my house would be out of commission.

So, what I'm thinking of doing is cutting off the toilet bend above, leaving about 2 inches of lead and using a fernco to go to ABS. I would also cut the lead vent as high as possible and cap it with a fernco (so I don't have to open up the wall).

In the basement, there is a wye that serves as a clean-out with about 1/4" of steel pipe sticking out. I would hog out enough of the lead (I'm thinking about a 1/4") to attach a flexible 4" to 3" connector, then use 3" pipe to connect to a toilet on a platform.

The advantages of this plan are that I wouldn't run the risk of pissing off my neighbor and chip up concrete, I wouldn't have to open any walls, and I wouldn't have to cut any cast iron.

The disadvantages I can think of are that I would still have a little bit of lead pipe, I worry about the stability of the connection to the wye after I remove some lead, I'd have a toilet on a platform, and...

Thanks for any help and ideas.

I would never "Fernco" onto a piece of lead, especially a closet bend, because it is a soft material and can compress/squeeze rather than seal to the coupling. And you should not use a Fernco inside the building anyway. YOU would have a problem connecting to the pipe under the floor, but a plumber would not. I haave never seen a drum trap installed that way with the vent tied into it.

You really need to get a vent on the tub trap. Doing that properly is going to involve opening the wall up above.
You may as well snap out that section of iron and redo it at the same time.
Mickey Mouse has his place, but a plumber he is not.
Rubber couplings are designed to fit on standard pipe sizes, made of ridgid materials. Old lead "pipes" are neither.
Leaded vent connections on drum traps are (were) very common in my area.

There is no vent on the new ABS plumbing. And again, the Ferncos are wrong.
If you want to connect to the cast iron stack, you would pull the pipe out of the hub, and work out from there.
It would be a good time to replace the lead bend on the toilet too.

I didn't open the full width of the picture, otherwise I would have told you to get rid of the "S" trap on the tub.

I would remove the 4" cast iron tee by grinding it in two pieces,splitting it vertically on each side of the upper hub before it enters the floor. Below the lower tee for the tub I would use a grinder or snap cutter and remove that tee as well.

Install a 4x2 left hand wisconson for the tub and toilet. Thats the easiest way to get rid of the lead and vent the tub. Seriously.

hj said:

I didn't open the full width of the picture, otherwise I would have told you to get rid of the "S" trap on the tub.

Click to expand...

That s-trap was first thing that caught my eye