copper pipe and cement

[jerseyjoe]

Hi

I just found this site and I know this isn't tile but I am hoping a plumber out there can give me the right story.

Last Spring a home inspector on the house I bought told me that the copper tubing in basement for the oil should be covered with cement. The previous homeowner did this.

This fall the oil serviceman who serviced my furnace told me to rip out the cement that it would cause pin holes in the copper tubing.

I went back to the home inspector he maintains that it should be covered with cement for safety and it is even a requirement in some towns.

Who's right?

Thanks,
JerseyJoe

[Davy]

Hi Joe, I'll ping Lonnie the plumber and see if knows the answer. Here in Texas we keep all our oil in the ground or in our trucks, we never bring it in the house. Hang tight.

[John Bridge]

Hi Joe,

I know that copper (water) tubing that runs through a slab is protected with a sleave to keep it from coming in contact with the concrete. I don't know how oil running through the tubing would change the requirement. Let's wait and see what Lonny has to say.

Davy,

In Jersey they don't put oil in the truck; they put earl in the truck.

[LonnythePlumber]

Cement eats into copper. You cannot have them in contact. Home inspectors are a problem. We don't have a national standard although some of them are being certified. State legislatures are attempting to pass legislation to require them to assume some responsibility for their advice and that they have some experience or training. It's almost like sending $25.00 someplace and Pow you're a minister or you have a degree. They provide a service that is really needed so I will be pleased when they become respectible.

[jerseyjoe]

Thanks all

I'll be chipping cement off the copper pipe.

JerseyJoe

[Davy]

Lonnie, how long does it take to eat thru a copper pipe? I have noticed the sleaves John mentioned in the last few years. My house is 27 years old and there aren't sleaves around the copper.

[LonnythePlumber]

I believe there is a chemical reaction that occurs and the time varies. The quickest I have seen is 5 years. Many have gone 20. We think it depends on the composition of the concrete but you would know more about that than I. Also the electric charge in the ground that is conveyed by the pipe may contribute. Gauge of pipe makes a difference.
It is not certain that concrete will eventually eat through your pipe. We have a bunch of 50 year old homes with the concrete poured around the copper and only a few of them have leaked so far. I wonder if the concrete today is different from that in the past?

[cx]

I've heard the discussion about Portland eating into copper for years, but have personally never actually seen it happen. I have always sleeved my in-slab copper in poly pipe (not the thin just-pretend red and blue sleeves you see sticking up outa the concrete on new construction) from end to end. It's mostly to protect it from physical damage before and during the concrete placement, though. I've had a number of failures of copper under the slab, but never from damage from cement. Nor have I ever seen any such damage in un-sleved copper I've removed or worked on in old installations. Maybe it happens, but I'm not entirely convinced.

And I agree with Davy about keepin' y'all's all inside the house. Sounds weird to me. I don't personally own none, but alla peoples I know that do keep theirs inna ground like Davy said. Onliest time they even bring any of it up is when they need a lotta dinero.

Must be a Yankee thing.

[Davy]

My spelling's gettin worse, spelled it "oil". I should have known it's "all" or "earl".

[LonnythePlumber]

Our copper gets pits in it. Looks like a shot gun fired at it or acid sprays that have eaten into it. The outside of the pipe is rough. It's not smooth any more.
Here's another twist with copper but no concrete. In half the country methane gas eats through copper vent pipe and the top of horizontal drain lines. Yet there are some states that require copper drain and vent because it lasts there. It's hard to separate prejudice from fact.

[cx]

Originally Posted by Lonny

It's hard to separate prejudice from fact.

Yep, you got that part right.

I have one house I built in 1985 in which I have pulled/repaired five copper leaks in the slab. One other house I built in 86 has had two such repairs. A few years later we learned that there was a seriously flawed batch of copper tubing from Mexico sold in this area during that time period.

But... In the second house I spent about 500 dollars having the copper and the water tested; both were OK at the time of testing but the laboratory said there had to have been something in the water at some time before the leak. The pipe was clearly damaged from the inside out and there was no damage on the outside (I was able to pull the pipe out of the sleave in that instance).

Of the five in the first house, we were able to pull the pipe out of the slab for three of the repairs. One was clearly a hole caused most likely by a piece of tie-wire from the reinforcing steel. One appeared to have rotted from the inside out. And the third pulled in half at the leak and was too deformed to make a certain determination.

Lotta failures in only two houses. Never have had such a failure in any other house or remodel of my doing. Have repaired other such failures, but none where I was able to remove the pipe intact to determine the cause of the failure. I have removed copper pipe during demolition for remodel that was run directly in concrete and it looked perfectly normal on the outside, pipe that may have been installed as long as twenty years earlier.

I've always ended up with a lot more questions than answers on that issue.

My opinion; worth price charged.

[John Bridge]

CX,

Clew: Don't runn yer wadder unner the slab.

[ESM]

I've heard it's the lye in cement that eats at copper pipes. Don't know if it's true.