Sink drain leak (pics)

Hello everyone,

I just moved into my first home - a 1965 single story concrete block house in FL. I noticed recently that the kitchen sink drain was leaking into the cabinet. Figuring I had a simple leak, I pulled everything apart only to find that the copper drain line (which runs into a concrete block wall) is heavily eaten away - it is paper thin in spots and gone in others along the bottom of the pipe.

Being a new homeowner, I'm a bit short on money so I'd like to try to tackle this repair myself. I consider myself very handy - I've done basic plumbing repairs before (copper sweating, PVC drains, etc), but nothing that involves concrete demo. Can anyone offer any suggestions?

I've got a small air chisel, a hammer drill, angle grinder (no diamond blades yet), etc. Should I just keep cutting until I find solid copper pipe? Should I just replace the horizontal portion of the copper drain?

Here are some pictures of the area if that helps.

The pipe


The pipe makes a 90 deg bend inside concrete towards the dishwasher.


The inside view of this wall


The outside view of this wall

Thanks for any words of wisdom you can offer!

- Joe

I'm assuming this is a house on a slab without a basement? Copper in that condition could have similar problems under the slab...could be a big problem - things could be leaking into the ground. Scrap copper is worth around $3/pound, so don't just throw it away. Copper should be sleeved when it goes through concrete - makes it a little easier to deal with and protects it. Wait for one of the pros, but it could get messy.

A no-hub connector might give you a temporary fix because of the rubber sleeve might bridge that gap, but when you tighten it down, it could warp it since it is not a nice round full tube.

Hello jadnashua,

Yes, this is a house on a slab with no basement or crawl space. I had a plumber here a couple of days ago to snake the lines and he said the lines were cast iron. He didn't run a camera up in there and didn't even look around the house so I'm not sure how he knew that - maybe he just guessed.

I tried putting a fernco/flexible coupling on that part of the pipe and it still leaked - just further back. As you predicted, it just deformed the pipe.

Thanks,

- Joe

You are about to go on a search and destroy mission for a good pipe where you can attach the new pipes to.

It doesn't get any better than that!

Hopefully you find some soon without tearing up the place too bad...

Listen... relax for now and watch Tom Hanks in The Money Pit tonite! Just remember it won't be that bad!

You say you used a Fernco coupler. If this was the neoprene sleeve with 2 clamps, that is the wrong thing. You should get a no-hub aka banded coupler. These have a solid band the length of the sleeve. It's may be you crushed the pipe with the hose clamp. Also, the neoprene sleeve is not approved for above ground applications. The banded coupler holds the pipe ends much better.

The sleeve I used was thick black rubber with two hose clamps on either end. Don't worry - this is only a temporary fix. I plan on re-doing my kitchen in the next year or two and will address this in a less "sketchy" manner then. I just put in a new central A/C unit and just can't afford to rip the kitchen apart right now.

If anyone else needs a quick, temporary fix for something like this, I internally sleeved the copper pipe with a piece of 1-1/2" PVC sink drain pipe cutting the end at a 45 deg angle to not obstruct flow in the 90 deg elbow. I coated the copper and the PVC with automotive RTC and used the black rubber coupler to clamp the two pipes together. So far, no leaks.

Thanks for all of your help!

- Joe

Man, I love creative solutions like that. Good thinking re the angle on the end.

Sounds like somebody in the past might have used a corrosive drain cleaner that did a number on your segment of copper waste pipe. I hope the plumber was right about the cast iron. Where in FL are you? Your local building dept might still have the as-built plans and inspections on file, but they usually toss them after 20-30 years. Check with your neighbors to see what they might know.

I'm in Boca Raton, FL - about 40 minutes north of Miami. I just noticed an error in my post - I coated the copper and the PVC with RTV not RTC.

I'll check the building department but from what I've been told, FL contractors are known for not pulling permits for the work they do.

The main cleanout outside my house looks like it is cast iron. Would that indicate that the main sewer line in the slab is also cast iron or would they have switched materials?

Thanks,

- Joe

I figured out the RTV thing OK. With a tube of that and a roll of duct tape, you can fix darn near anything.

Even in FL, it's pretty hard to avoid permitting new construction -- remodeling is another story, however.

I'm guessing (one of the pros can provide a much-more-educated guess) the CI cleanout implies a CI pipe, so you're not likely to have serious leaks under the house. Your ultimate repair will probably be to replace the copper with PVC from the sink to the CI. An easy job once you gain access to the waste line, probably easier from the outside.

I've seen 30-year-old Tyseal CI pipe eaten clear through for a 60' horizontal run hanging in a basement. Goes to show that overuse of drain cleaners isn't a good idea. I'm not able to say that's the case here. Having copper buried in block walls is surely not something I'd be looking forward to fixing - I'm feeling for ya.