Replacing copper pipe with PVC???

[DaveDay]

My 20+ year old wooden home has copper water pipes throughout.

For some reason, the 3/4" hot water pipes have all decided to die at about
the same time. I have gone under the house and done 3 repair jobs on 3 sections of pipe so far over the last 4 months. Each leak was in a stretch of pipe, not in a joint. -- though the joints don't look great.

I am concerned enough to be thinking about a complete replacement job. I notice that pvc is about 1/3 the cost of copper, and I find it easier to work with.

I seem to recall that the copper pipe is normally part of the grounding system in homes with it. So there must be some electrical grounding work required before I could switch it out.

Anybody know about this???

Thanks in advance for your thoughts.

Dave Day

[maxparot]

PVC pipe is generally thought to be 15-20 years of use. If your copper pipe is only lasting this long it's past time to consider why? Does it go through near freezing cycles or is your water hard? If the pipe is expanding because of freezing insulation of the pipes and or the space where they are located may solve the problem. If it is corosion then a whole hose treatment system should do the trick. Copper pipes should last a lifetime.

[JimD]

Dave,

I live in Lexington, SC - nearby. We had our house built when we moved here in 1999 and the builder used CPVC piping. He said it would last longer than copper. I do not know about that but it was cheaper. I finished two bathrooms myself and also used CPVC for the first time ever. I have soldered quite a bit of copper but glueing CPVC is far easier and faster. The only thing I used copper for was the riser from one of the control valves for a shower to the shower head - I think copper makes the shower head more solid.

I would use CPVC is I was you. I agree, however, that it would be good to know why your copper is failing. Plastic may last longer but it would be nice to know what happened to the copper, it should not be corroding this fast.

The water pipe should not be part of the grounding of the house. If it is, you will have to reconnect it to a grounding rod. That is just run a wire outside, buy a grounding rod at the home center, pound the grounding rod into the ground, and connect the grounding wire.

Jim

[JSUPreston]

Dave,
The water pipe should not be part of the grounding of the house. If it is, you will have to reconnect it to a grounding rod. That is just run a wire outside, buy a grounding rod at the home center, pound the grounding rod into the ground, and connect the grounding wire.

Jim

Jim, I read in my wiring book at the house the other day that it is acceptable to use the cold water pipe as a ground. This was one of those basic home owner wiring books, so there obviously could be some mistakes in it. However, I've seen a lot of grounding here in Alabama that uses a water pipe going into the ground.

[Deadhead]

I would use CPVC is I was you. I agree, however, that it would be good to know why your copper is failing. Plastic may last longer but it would be nice to know what happened to the copper, it should not be corroding this fast.

The failing copper is probably due to the grade of copper used. My dad had the same problem in his ~20 year old house - except it was the upstairs leaks that kept showing themselves on the downstairs ceiling. After having the leaks professionally cut out and replaced, and having the drywall professionally patched 3 times, he decided it was time open up the ceiling and replace all of the copper. We replaced it with CPVC.

As it turned out, he had a cheap grade of copper. There were many, many leaks in the near future for that pipe. Some you could see from the outside as green streaks, some you could see from the inside as little mounds of desposits trying to eat through the copper. One of the downfalls of new construction is in a lot of cases (not all), the job goes to the Sub who bids the lowest price. If you ask the builder to include a car with your house, he's going to give the job to the Sub who bids a Yugo and not the one who bids a Lexus. It's just the nature of the business in a hot building market.

Now, fast forward about 1 year. My dad just had his electric water heater relocated/replaced from the utility room to the garage. He hired a very reputable, full service plumbing company to do it. Sure, they cost more, but the peace of mind is worth it. Guess what they used......high grade copper! They said that when PVC fails, it literally explodes under pressure and the resulting "leak" is like cutting a section out of the pipe. If/when the high grade copper fails, it will be far less damaging.
He plans on having them replace the low grade copper under the house with high grade copper.

If you don't plan to be in the house for long, the CPVC may be the way to go. And if you disclose that the plumbing was replaced with CPVC (especially if it's hidden in the walls or ceilings where a home inspector can see it) then you should have peace of mind about selling it to someone else.

(Someone else will have to help out with the grades - I think his low grade was J or K and the high grade used was M, but I could be totally wrong).

[parnelli]

I think his low grade was J or K and the high grade used was M, but I could be totally wrong.

Heck, I didn't even know there were different grades. That explains stuff in my house....anyhow- did a google search and found this:




QUESTION:
Is all copper plumbing the same or are some grades more susceptible to corrosion?
ANSWER:

All copper plumbing is not the same grade. Some corrosion leaks are due to the quality of copper used for the plumbing. There are three grades of copper thickness referred to as K, L, and M grades, where K is the thickest and M in the thinnest. Since type M is the thinnest grade, it is also the cheapest and most susceptible to corrosion leaks in the shortest period of time.


And this:


Copper comes in three grades, M for thin wall pipe used mainly inside homes, L for thicker wall pipe, used mainly outside for water services and K, the thickest, used mainly between water mains and the water meter. Copper lasts a long time, is durable and connects well to valves.


Copper should not be installed if the water has a PH of 6.5 or less. The majority of public utilities supply water at a PH between 7.2 and 8.0 . Many of the utilities that have source water with a PH below 6.5 are treating the water to raise the PH. Private well water systems often have a PH below 6.5. When this it the case, installing a treatment system to make the water less acidic becomes a good idea.

[LinuxRandal]

I have gone under the house and done 3 repair jobs on 3 sections of pipe so far over the last 4 months. Each leak was in a stretch of pipe, not in a joint. -- though the joints don't look great.

I seem to recall that the copper pipe is normally part of the grounding system in homes with it. So there must be some electrical grounding work required before I could switch it out.

Anybody know about this???

Thanks in advance for your thoughts.

Dave Day

UNDER THE HOUSE? Are you talking crawlspace, where the metal can get fatiqued by being exposed to freezing tempatures? If so, cpvc would be worse. Others have posted good suggestions, I am just going to add, locally, there are three things that get grounded to your cold water pipes. You have the neutral bar from the electrical box, that has a line out, that leads to the input side of your cold water line (if you have an inside meter), The phone line grounds to it, and the cable service entrance. You would need to jump these all to the entrance, if they are anywhere near these lines.

[JSUPreston]

I was watching an ATOH episode a couple of weeks ago, and Silva said that no matter if the line is hot or cold, insulate it. If it is in a crawlspace and you can get to it, insulation is a whole lot cheaper than a plumbing job.

[DaveDay]

Thanks guys!

I continue to be amazed and thankful for the thoughtful responses I get when I post a question to bt3central.com.

I have seen at Home Depot that they sell two of the 3 grades of copper referred to in these posts, and of course the thicker ones are noticeably more expensive. I may well end up opting to install CPVC and insulating it.

Thanks again.

[don_hart]

My house was built 7 years ago and we made the decision to go with a flexible plastic piping in the house. I have to say now I will never use copper again. There are many advantages to flexible plastic piping in your house.

First off it is the only plumbing option that comes with a garantee. It has a 25 year one.

There is no expansion noises in the system. Those of you with oil fired hot water heat will appreciate this one.

The plumbing is run like the electrical lines. Meaning that it go through holes in your studs and joists. This means you will have no piping hanging below your joists in your basement and that istallation is easier.

Making any additions or changes in the system are very easy and quick. You can add a new T in a line in a couple of minutes. No pipe cutters no braising.

Can safely be frozen and will not burst

[Hellrazor]

Don: You talking about PEX?

[JeremyM]

He has to be talking about PEX. Nothing else works like that. It's pretty cool stuff overall.

I haven't plumbed the whole house but have used it to make repairs on systems. Once you are used to it, it's very, very fast.

[LinuxRandal]

My house was built 7 years ago and we made the decision to go with a flexible plastic piping in the house. I have to say now I will never use copper again. There are many advantages to flexible plastic piping in your house.

First off it is the only plumbing option that comes with a garantee. It has a 25 year one.

Please give a little more info on the guarentee! At our garage (family mechanics, I part time at), last year the main line burst, and by the time it was all said and done, the plumber replumbed it with pex, and installed a regulater at 60psi. He said there would be no warranty if it was more then that, but the pex line was marked at a higher rating (I believe 150psi). As this is close to my house, the average pressure (without regulator, like tons of these houses are) is between 100 up to 120.

[parnelli]

My house was built 7 years ago and we made the decision to go with a flexible plastic piping in the house. I have to say now I will never use copper again. There are many advantages to flexible plastic piping in your house.

Every time I see TOH use that stuff I wish we could use it here. Of course every time I see them run electric without having to use conduit, I wish we could do that as well. Sigh.

[billwmeyer]

Pex looks interesting, but I have never used it. I have redone 3 houses completely with cpvc pipe and have only had one problem. I missed some insulation on one pipe and it froze and broke. Copper will allow some expansion on frozen pipes. Cpvc will not. It is easy to use, and if you mess up, it is easy to redo. I will never do copper.

Bill