Plumbing Question: Leaking Cast Soil Stack.

NYSpeed Automotive NYSpeed Off Topic
1

I have a house built in 1920. I think it still has the original soil stack. It is a two family, I live in the lower unit. We totally remodeled the lower bathroom, then we noticed a leak coming in our ceiling (where the upper bathroom is.) I figured the floor was rotted out around the toilet upstairs, and the wax ring was not sealing.

A good buddy of mine worked for a plumber for several years, so he knows quite a bit.

He agreed to help me replace the rotted subfloor around the toilet, and basically remodel the bathroom for the tenants.

He quickly figured out that the toilet was not leaking at all, even though the floor was warped and rotten. We replaced the floor anyways.

The problem is where the sink drains into the main soil stack. The previous owner had a copper pipe jammed into the stack, and they put a shitload of epoxy around the fitting.

We figured that they were just being lazy, and they cut the pipe off or broke it off. So we spent about an hour with a MAP gas torch, and torched the old copper pipe out of the cast stack.

We pulled the pipe out (nearly causing a fire), and we installed a proper donut into the cast, and ran the PVC drain pipe to that.

To test it, we ran some pressurized water directly into the plumbing. It turns out that the cast stack is leaking right at the bottom of the Y fitting. That explains why the previous owner tried to install a homemade sleeve to stop the leaking.

This is on the second floor of a 3 story house, and the cast iron goes out to the roof. Replacing the stack from the 2nd floor up would cost a shitload of money. The labor would be insane, and it would replace the cast with PVC.

So right now for an emergency, I bought some JB “Waterweld”. I have used this stuff in another apartment before to seal a rust hole in a bathtub, and it lasted for 5 years.

I applied the waterweld to the leaking cast, and it is not leaking anymore, but who knows how long it will last.

For right now, we have tenants upstairs who need (and pay for) a working bathroom. We remodeled the entire bathroom, and left an access panel in the drywall so that we can have it fixed right when they move out.

I have a fucking roasting pan sitting in my bathroom ceiling to catch any water that may drop down, nothing yet, but I’m paranoid. Instead of replacing the ceiling, we just cut out all the wet parts, and used clear plastic sheeting to seal it off (so I can see if its leaking).

Does anyone have any idea of a more permanent solution than a JB weld product?

The only thing I can come up with is something like this.
http://www.fernco.com/waterworks/flexible-couplings/flexible-tap-saddles

But I would prefer a custom metal piece that inserts into the stack, sealing it. Not a ghetto copper pipe epoxied into the stack. If such a product doesn’t exist, does anyone have access to fabricate a custom insert?

I would like to avoid spending 3 grand replacing a cast stack, and I also like to sleep soundly at night not having to worry about sink water dripping into my bathroom (at least it isn’t shit water as first thought).

I have attached a photo I took today with my phone to show the pipe after we had “repaired” it and installed the donut and the PVC, and a photo of the finished bathroom. Between the floor, subfloor, faucet, vanity, mirrors, and lights, I have less than $300 into the project.

It is a rental, nothing high end like what is usually posted in this forum.

2

photo of finished bathroom (until the next disaster).

3

How big is the crack? The epoxy might actually hold for quite awhile, moreso if you cleaned the surfaces really well. It helps a lot that it’s not under pressure. It’d be really hard to do where it is, but you could braze the crack, but you’d likely set the wall on fire. Another option is to cut the tee out and replace it. Is there anything supporting the pipe above the tee so you can remove it? If not, you might have to figure out a way to hold it. If you can come up with something to accomplish that, you can remove the tee and replace it with a rubber repair fitting. I’m not sure what the exact technical name is for them, but you can get them at Lowe’s and Home Depot. They’re black rubbery repair fittings that slip over your existing pipe and are held in place by hose clamps. They work really well.

4

The crack is not long, maybe a quarter of an inch. Its not under pressure at all, and its just a hand washing sink, so its not carrying feces or anything like that.

Cutting out the branch, and replacing it with another cast piece would be some work as well, I have no idea how it is supported.

I will have to look into those hose clamp things, they are being called “saddles” by many of the manufacturers. I would rather not cut the pipe at all.

5

Its called a Fernco. They are used for connecting pipes together, so he would have to cut the pipe to get it on there. Hmmm I’d say try a pipe repair clamp. But I’d have to see what it looks like to really make any kind of educated call. I was a commercial plumber for 2 years at Darien Lake. I fixed God only knows how many leaking/broken pipes. Depending on how old the pipe is, you may be better off just replacing it. I know it is expensive, but it will only deteriorate worse over time, causing more damage. As far as holding the pipe, you can always use some all thread and anchor it to a wall stud, which is how it should be held into place to begin with.

6

maybe some rtv over the epoxy? I dont see why it wouldnt hold if it was dry and clean.

7

its not under pressure, i think you will be fine long term even with jb weld

8

roof tar, pipe clamps and some sheet metal flashing… tar up the pipe, wrap it in flashing and clamp it down… once the roof tar sets up it won’t ever leak again