Copper rot??? Plumbing issues

[mattl]

Got a question to toss out to all the experts. I have a 1 1/12" copper drain line from my kitchen sink and DW. A few years it developed a leak and I cut it off 4" past the problem area and replumbed with PVC from that point on. Used a Fernco adapter to go from the PVC to the copper. The pipe had developed what looked like a razor slit on the bottom. Thought it was odd but did not give it much thought.

Over Thanksgiving I smelled something like an electrical fire, a vaguely ozone smell. Looked around and found nothing and the smell came and went a few times. Yesterday I went down the basement to get something out of a closet behind the fireplace and I notice my stack of audio equipment is wet! Didn't blow a fuse or anything. The same problem developed again -- a thin slit on the bottom of the copper drain line going from the coupler back about 3". This is buried in the ceiling and not too far from this point it goes into the poured basement wall so if this keeps happening in a few years I won't have any pipe left to cut off.

Any idea why this is happening? Should I cut it back all the way and hope for the best? The whole house has copper drains, this is the only trouble spot.

 

[sudsmaster]

I'm no plumber but I don't think copper is a great choice for plumbing drains. Copper is attacked by various acids, and the usual use for it seems to be for tap water supply. Even then, if the municipal water supply tends to be soft and on the acid side, copper pipes don't last as long as they should.

There's one copper drain pipe in my house - from the washer in the laundry closet to a lateral iron pipe line. Most of the time the effluent from the washer is alkaline, except when I use a vinegar final rinse.

I figure over time bacteria growing in the drain have exuded acid byproducts that have attacked the copper in the drain. It may be selective for any seam in the copper, or just collect at the bottom. That would account for the slit leak. I've seen similar slit type leaks in thin brass P-traps under sinks, so it's not all that unusual.

In my town, the plumbing code says that only cast iron can be used for drain pipes. This didn't stop the previous owner from using aforementioned copper for the washer and even plastic for a semi-legal half bath off the patio. But maybe the code was more lenient back in 1975.

I suspect that over time you'll find more leaks from those copper drains. At this point you might want to call a plumbing company to see if there is a danger of more developing, and what can be done to fix the problem without having to demolish concrete. There may be some plastic lining solutions that would work.

 

[rayjay]

Hi Matt. I had the same problem in the kitchen. Two years ago, the copper pipe from the PVC trap in the kitchen developed a small leak. Plumber cam in cut the pipe added a rubber boot along with a PVC extension. This was year, it happened again. This time he took the whole pipe out and replaced it with a PVC pipe to the main sewage stack.

Now we just had the kitchen renovated. The plumber put in a whole new PVC in the wall. It is now out of the way. Hopefully will not ever have any problems again

 

[everythingold]

copper is the only way to go for main lines, but drain lines should be PVC. It seems to me that you are having back pressure leaks. as you fix one split copper length, it puts more pressure back up the line. any weak spots then split. Still 1.5" pipe is pretty big. A rig job might work, wrap the hell out of it with duct tape ot something. Just use something to reinforce the copper portion. Also, mixing metals in water systems can cause corrosion brcause they have differesnt electrical potentials. But I am not a plumber. Matt

 

[sudsmaster]

I'm still trying to figure out why copper drain pipes were used in the first place. It's a sort of expensive material, and ABS is a much better choice for localities that allow it - or cast iron for those place that require it.

I guess at this point I'm thinking I need to visit the crawl space to check on the copper washer drain line. I have to go down there eventually to finish tacking insulation under all the flooring...

 

[rayjay]

I'm still trying to figure out why copper drain pipes we

Hi Rich. Our home was built in 1959. I think that is they used. I thought that copper was supposed to be stong also. Now, my neighbors who have a custom built home, had the same problem within a year of each other. The copper drain pipe from their bathroom sink got a leak. They had to take the tile off the wall and replace it. What a mess.

Now when we were doing our kitchen renovation, I could see our copper drain pipe from the bathroom sink going into the main stack. It was solid as a rock. The pipe was pitched, so no water lays in the pipe. I was going to have it replaced, because of our neighbors problem, but my contractor said it looked fine and to leave it. Well....in a couple of years when I do the bathroom, I will definately have it replaced then.

Ray

 

[rayjay]

Cast Iron

Cast Iron is great for the main sewage stack, but I do not think it is good for drains, in that water, grease etc. could lay in it and corrode it. Where as copper or PVC does not have this problem. I think SChedule 40 PVC is the way to go. You would never have to replace it.

 

[sudsmaster]

Um, grease will not corrode a cast iron pipe. If anything, it would prolong its life. There are cast iron drain pipes under this house that are 60 years old and show no signs of leaking. Cast iron also doesn't rust as rapidly as steel. In fact, once it starts to corrode, a protective layer naturally forms that is resistant to further corrosion. And it's usually thick enough that it can withstand a lot of corrosion before it fails.

Cast iron is also much quieter than plastic pipe. This can be very important in a multistory dwelling.

Copper also forms a protective oxidation layer in an alkaline aqueous environment (above 7.2 pH). But this layer can be stripped away in acidic water, and copper is also susceptible to attack by sulfides (a popular anti-dandruff shampoo contains selenium sulfide - don't know if it's enough to cause copper corrosion, though).

 

[mattl]

The house was built in '65, and it's copper throughout. I replaced that section today, and took a look, if the rest goes it can be replaced but with some difficulty. The copper goes into a brass hub which looks to go into a 3" drain line. From what I can tell looks like it's set in with Oakum.

Only problem? It's behind 2 6" round heat runs, and the 2 waterlines that feed the back bathroom.

This is the THIRD Plumbing issue I've had this week! Had a leaky toilet in one of the upstairs baths ruin the dining room ceiling, $250 to fix the ceiling a couple of weeks ago, and yesterday my brother noticed it was all bubbled again! I set the toilet well, but did replace the sink, so I redid the drain lines up there, the p trap was just a bit short, might be the problem. Have avoided using that toilet and sink waiting for it to dry up. Then I'll add one back in until I know where the problem is --don't want to tear out the ceiling again!

The third issue is the basement laundry. My laundry room backs up to another bath and for the last week every time I do laundry the water in the toilet bowl bubbles up with some force. I use a stand tube in the laundry tub and it was blocked with some lint, but cleaning it didn't solve the problem, guess I'll check the vent.

God I hate plumbing!

 

[retro-man]

I have had the same issue with copper drain pipes. My house has copper for the drains in the kitchen and baths upstairs. I have cut the copper drain in the kitchen cabinet right down to the bottom of the cabinet floor. Seems to be some sort of connector there where I have put pvc up to that point from the garbage diposal and dishwasher. The same problem as yours was happening. Never have had a problem with the bathrooms. I have checked recently and they are fine. Must have to do with detergents and drain cleaners used over the years since no problem in the other parts of the house. As far as your problem with the toilet bubbling when the washer is draining: with the condition of your father is it possible that he is flushing things down another toilet that should not be? I had this problem in 2 of my rental properties. Older people with dimentia were flushing pads of all sort down the toilet. While it did not block the flow entirely is reduced it enought to have the washer stand pipe back up while washer was draining. Had to have roto-router come in and clear out the main drain to the street. They can send a camera down the pipe to also find and see the clog. Pretty neat tool. Good luck my friend.
Jon

 

[polkanut]

My parents home was built in 1922, and mine in 1925, and all our drain pipes are either PVC or cast iron. Neither of us have had any problems with the pipes degrading. The only reason that some of the pipes are PVC is due to remodeling projects. Both homes even still have some lead pipes too. I know they should be replaced, but with the amount of water that goes through them, the water doesn't have much time to absorb that much lead.

 

[swestoyz]

It really is a shame that the copper drain pipes are not holding up past the 50 year mark. Great idea back then, but now will be causing more problems for home owners for years to come. My grandma's house, built in 1960, is completely copper in the branches, but thankfully the stack is cast iron.

Cast iron also has it's own issues as well. House was built in 1914. Main stack was rotted from the inside out. Once they hit the 100+ year mark it is a good idea to have the whole system inspected to make sure you are not getting rot from the inside out, which in my case was happening on the main stack, as well as the branch from the kitchen.

Glad I was able to catch it when I did. This hole was caused by barely putting pressure on it with a soil pipe cutter. Nasty stuff.

Ben

 

[sudsmaster]

Old Cast Iron may not be perfect

Modern iron pipes that have been manufactured with a spinning technique are more uniform and have fewer defects than older pipe that was manufacturing using a casting process, and thus can last longer with fewer failures. Nothing lasts forever, so of course inspection of very old plumbing is a good idea, to help prevent failures before they cause other damage to the structure.

 

[launderess]

Nothing Lasts Forever

Oh I don't know! *LOL*

There are cast iron water pipes in NYC that have been in the ground for over one hundred years, and are doing fine. True the things do rupture and crack, but still.

This whole conversation puts one in mind of that scene from the film "Moonstruck" when Cher's "father", a plumber, is trying to sell (some would say fleece" and upscale couple about having the piping in their bathroom done with copper.

Cosmo Castorni: " There are three kinds of pipe. There's aluminum, which is garbage. There's bronze, which is pretty good, unless something goes wrong. And something always goes wrong. Then, there's copper, which is the only pipe I use. It costs money. It costs money because it saves money."

 

[sudsmaster]

Minor correction:

Modern iron pipes may be made with a spun cast method. Older pipes may have been made with a sand cast method. The sand cast method is more prone to pinhole discontinuities and irregularities that shorten the life of the piping. I gather that the care with which a pipe is sand cast makes a difference as well. The spun cast pipes are more uniform, more free of defects, and stronger.

I've never heard of anyone using aluminum for drain or water piping. Nor bronze, although most under-sink piping seems to be chrome plated brass, which seems to last maybe 20 years before it corrodes to the point of failure.

The difference between brass and bronze? True bronze is made with copper and tin as the main ingredients. Brass is made with copper and zinc as the main ingredients. A nmemonic to help remember is that the name with a "Z" (bronze) does NOT contain Zinc.

Of course Hollywood script writers often play fast and loose with scientific/engineering facts, but I wouldn't put it past a dishonest plumber to present a phony two out of three options to a customer as a sales technique. I'm surprised he didn't mention paper mache.