Our 20 year old copper pipe is starting to fail. It was a poorly done job in cheap copper. There have been a couple of pinhole leaks in the walls recently and I am worried about the future.
Will the epoxy treatment where epoxy is pumped through the lines work to prevent the deterioration of the pipe?
The house is not subject to freezing so there may be low spots that do not drain. Will the epoxy work in those areas and will the pipes plug up with epoxy there?
We are planning to recarpet, should I redrywall and plumb at the same time? $$? I will be doing a bit of that anyhow but replumbing the whole house is a much bigger project than I was hoping to have to do. Also it is a triplex with tenants in the other units who cannot be disturbed – either by rennovations or the water damage from the leaks.
Eric
Replies
I don't think it would be worthwhile to spend money on a poorly done job with old inferior leaking copper pipe. I read that they use this as a preventative, not restorative, measure on new pipes. The pipes are "sanded" inside with garnet particles mixed with water to get to bare copper. Your pipes may be coated with lime scale inside, which would be tough to sand. They may have to use an acid to remove the scale.
I think replumbing is in your future. Perhaps PEX could be installed with minimal drywall destruction.
I've never heard of this technique, and I'm a bit skeptical of whether it would work on "used" copper (if it works at all). In addition to the problem of buildup in the pipes, you have to problem of simply getting them dry so the epoxy can stick.
I'm guessing you live in an area with corrosive water. Normally copper pipe is good for 50-100 years, but in certain parts of the country (I'm thinking Florida and some of the Gulf Coast) the water is acidic and eats through copper fairly rapidly, often in ten years or less. In such areas it's probably best to bite the bullet and replace as much of the copper as possible with PEX.
Another option is to add a neutralizer to your water supply. I believe these work by running the water through a bed of limestone or marble chips. They raise the pH of the water to where it's no longer corrosive.
It is done, mainly on large units like condos and apartments etc. The pipe is dried by blowing hot air through it. It does sound like the process is rather iffy to me though.
Your problem may not be as bad as you think. The differences in various grades of copper pipe (or, more correctly, copper tubing) are based on wall thicknesses, not the actual composition of the metal. It is highly doubtful that your building has "cheap copper". Even the thinnest wall type (Type M, as opposed to Types L or K) should easily last the 50-100 years that DanH mentioned.
The couple of pinhole leaks that you have seen could be due to a number of things that may not mean that the whole system is on the verge of failure.
If, for example, the leaks have been near a soldered joint, and downhill from the joint, it could well be that the leak was caused by flux pitting. This happens when a blob of overheated flux that was left there during the soldering process remains stuck to the wall of the tube. Over time, the acid in the flux will eat a pinhole thru the copper wall.
Another common cause of pinhole leaks is due to erosion, usually on a hot water line that has a re-circulating system. The constant flow of hot water, especially at a high velocity, will erode, or wear away, the copper. This usually shows up near a sharp bend in the line that creates extra turbulence. You did not mention that your triplex has a re-circ system, but I mention this as another example for the cause of pinhole leaks.
So, if you can take a lttle time to identify the problem, you may find that your copper sysem is essentially sound, and good for many more years.
I suggest cutting out a short section of tube, preferably one that includes a soldered elbow (replace it with another piece of tube, connected with Sharkbite fittings), and then, using a hacksaw, split the sample section along its length. If everything looks good inside, that's a good indicator that the system is not deteriorating as a whole.
If the sample looks bad, you should send it to the Copper Development Association http://www.copper.org/ to have it analyzed. DO NOT hand it to your plumber for his opinion. His job is to sell plumbing jobs, on top of which, he may have very limited knowledge of copper's potential problems. You could even send CDA a good digital photo of the halves of the cut-out section for a preliminary analysis.
I have had this happen in a few condo units where I lived before. It was caused by a copper colored steel strap being used. I think the installing company did it on purpose because every time it was in the exposed utility room. It took 25 years before the copper had a pin hole leak.
How does a copper colored steel strap cause copper tubing to develop a pinhole leak?
Galvanic corrosion (some times called dissimilar metal corrosion).
Two reasons why that probably wasn't the cause:
1) Steel is sacrificial to the copper, not the other way around. This means that it's the iron or steel that will be corroded away, because, in that combination, steel is the anode and copper is the cathode. This is quickly confirmed by looking at the galvanic chart for metals http://www.corrosionist.com/galvanic_corrosion_chart.htm
2) Both metals would have to immersed in electrolyte for galvanic corrosion to happen. Even if a minor amount of water from condensation happened to be present between the strap and the copper, see #1.
I don't mean nitpick your post in partiular, it's just that this misconception is so widespread that it needs to be stopped. (And plumbers like me are the worst culprits for spreading it. They use it to explain leaks in copper that are actually a result of poor design or workmanship.)
What you say is correct, however since this happened to me and a few others I can attest that there was a leak and it was caused by corrosion. This link is exactly what I had encountered: http://www.finishing.com/246/64.shtml and it does explain why the corrsion was not at the contact of the pipe strap and the copper.
Clicking on the link you supplied gets me to a page that says: "Sorry, that link is broken."
Thanks for the input. The triplex does have a circ pump. The problems have all been in sharp bends (except for the nail through the pipe). There was evidence of corrosion from flux. There are lots of sharp bends that our repairs replaced with smooth pex and sharkbites.The pressure drop when someone uses water ruins the shower. There are lots of problems. I would like to isolate the showers with home run pex so a bit of drywall work is needed.
But replumbing the whole house is a bigger project than I want to take on. So I am still looking for anyone with actual experience (good or bad) with epoxy lining of older copper.
Eric
You might also reduce or even eliminate the leaks from the erosion effects of the circulating system by slowing down the flow from the re-circ pump. This can be done by installing a ball valve at the outlet of the pump. You would use it to throttle down the flow to the minimum needed to maintain the temperature you want in the hot lines.
Erosion of the copper will be reduced both by reducing the water velocity and by lowering the temperature of the circulating water, if practical.
As for your original Q, I am not familiar with just how complete and effective epoxy coating of small diameter lines would be. Before going ahed with that, you really do need to get input from someone who has experience with it.
It should be noted that there would be substantial cost savings in turning off the pump or putting it on a timer.