CPVC/PVC plumbing questions

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I am running new plumbing lines in the basement of a 3-unit apartment building that I own. The purpose of the re-plumbing is to separate out the water service for each unit. All of the existing plumbing is copper. The hot and cold copper lines that go to each individual apartment are easily accessible in the basement, so separating out the water service for each apartment will be easy because all I will need to do is tie into the copper lines for each apartment in the ceiling of the basement.
I don't want to use copper, and I think I am probably not going to go with PEX. My plan right now is to use CPVC pipe and fittings for all of the new plumbing and to tie that into the existing copper lines for each apartment.
One question I have is whether to use all CPVC, or use CPVC for the hot water lines and PVC for the cold water lines. My inclination is to use all CPVC rather than try to save a few bucks on materials by using PVC for the cold water lines. Does that make sense? Is there any reason NOT to just use all CPVC instead of trying to use both CPVC and PVC, other than the cost of materials?
I also have questions about how to connect the CPVC to the existing copper lines. I can easily solder female threaded adapters to the ends of the existing copper lines and use male threaded CPVC adapters to make the connections. But, I think there may be a problem with doing that for hot water connections due to possible variations in expansion of the two materials and, therefore, possible future leaks at the connections. I have seen the Sharkbite and Watts push-on connection adapters but they make me nervous in terms of how secure the connections would be. And, I believe there are copper to CPVC adapters that either screw onto, or get soldered to (I am not sure about that), the copper and then are glued to the CPVC pipe.
I would appreciate any thoughts or suggestions on how to best make the connections from the CPVC to the existing copper.
And, any thoughts, suggestions, pointers etc. regarding the whole CPVC (or CPVC and PVC) project would also be appreciated.
Thanks.
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It's not what you asked, but I'd stick with copper in an existing building with copper plumbing. I would not change horses unless *all* of the plumbing is coming out. Then I might go with PEX, but I'm not a fan of PEX either.
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The grounding/safety long term service requirements favor copper. Tenants can do unbelievable things to facilities, so saving a few $$ doesn't make sense.
Joe
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Joe wrote:

See my earlier reply regarding the electric/grounding issue.
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Bob F wrote:

........
Thanks. I'm not sure if that would work. I read somewhere that there can be problems with the female CPVC threaded fittings cracking when tightening and that using male CPVC threaded lessens the chances of cracking.
I just went to Lowes and saw some "transition unions" that can be soldered to the copper and then use a compression fitting (similar to a garden hose connection/washer) that converts to a CPVC glue fitting. Here's a link with some of those types of fittings: http://milo.com/nibco-34-in-cpvc-transition-union-brass-and-cpvc .

The 3-unit building has all new electric wiring throughout. And 4 new service panels (one for each unit and one "house" panel) were installed by a licensed electrican with all the rquired permits, final inspection, etc. The new service panels utilize the current code requirements including two 8-fot grounding rods located 6 feet apart; the required jumpers across the hot water heaters, and the water meter, etc. So the electrical system does not rely on any cold water pipe grounding. I think the new codes take into account that people now use PEX, PVC, etc. which would make cold water pipe grounding not reliable since there can be in the continuity of the pipes.
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RogerT wrote:

I'd go with the CPVC only on the half inch stuff. That's what I did for most of my plumbing. The PVC is a little larger diameter so you will get more volume for the same size if there might be a problem with adequate flow in a cold water "main feed" system. Sounds like a rent place? Large manifold pipe for supply, cutoffs to the individual units etc. And when I had rentals I always kept the battery for the sawsall charged, a metal cutting blade and various caps and plugs so I could cut into a pipe and cap or plug it until a permanent fix could be done. For transition from metal to plastic I usually screwed a threaded plastic male into the female metal threads and then glued the plastic from there. In your case a soldered female copper and then a male plastic. That way if you need to you can cut the plastic line and unscrew it at the transition. I never had it happen but supposedly the hot water can back flow if a HWT over heats and flow enough hot water through PVC under pressure to cause problems on the cold water side of a HWT. Be sure to use only code approved CPVC glue for long, hopefully forever trouble free joints and connections.
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On Sep 16, 3:33am, FatterDumber& Happier Moe

Was just looking at some new construction here in NJ and they used CPVC for both hot and cold. Which is what I would do instead of using half PVC, if I were going that route.
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RogerT wrote:

For system "earthing", the NEC has for a very long time required that if there is a metal water service pipe, at least 10 ft in the ground, it be one of the earthing electrodes. It is far better than ground rods. For many years the connection has had to be within 5 ft of where the pipe enters the building, and the water meter must be bonded across. If you have a metal water service pipe, the system depends on the cold water pipe for a "ground". Sounds like that is what you have.
You used to be able to make a ground connection, such as adding a ground to an existing receptacle, to a water pipe. That has not been allowed for many years because, as you say, there may be plastic in the future. Using plastic pipe inside the building is irrelevant for grounding.
--
bud--

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bud-- wrote:

Thanks. I checked and, yes, that is what I have. The new service is grounded to the metal cold water pipe where it comes in through the wall (before the meter), there are jumpers across the water meter and hot water heaters, and the system is also grounded to the two 8-foot grounding rods that are 6 feet apart.

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If I am remembering correctly, plumbing codes only allow standard PVC for outdoor use (underground supply lines, irrigation, sprinklers, etc.). You must use CPVC for indoor supply lines (both hot and cold).
CPVC offers a number of advantages over copper, including lower cost, easier installation, better resistance to acidic water, no risk of starting fires from soldering, not likely to be stolen by copper thieves, etc.

NEVER use a female fitting made of PVC or CPVC. They aren't allowed by code and my own experience shows they have a nasty habit of cracking, either during installation, or some time in the future. I'm not sure why they even sell them.
You CAN use a male CPVC fitting threaded into a metal female fitting. Just apply a few wraps of teflon tape before assembling, and don't go crazy tightening it. I have done this many times, but as you mentioned, you could potentially have problems later on as the two materials expand at different rates. I would only use this approach if the connection were accessable and I had no other option.
I plumbed our entire house using CPVC and transitioned to brass fittings (drop ear elbows and whatnot) where needed using special transition unions. Basically, these have a brass connection on one side, a CPVC connection on the other, and a rubber gasket between the two. A threaded ring tightens it all together. They're not cheap ($5 each if I'm remembering correctly), but compensate for different expansion rates. While they do make drop ear elbows out of CPVC, I would never trust plastic for a stress situation (shutoff valves, shower heads, etc.).
In recent years I have seen one piece molded adapters, where a CPVC fitting is molded around one end of a metal fitting. They seem to cost less, but I have no experience with them to know how they hold up in the long term.

For 1/2" and 3/4" CPVC, pick up a plastic pipe cutter (looks like a ratcheting pair of pliers). It's fast and makes nice clean cuts on the pipes.
Remember to clean the pipe and fitting with primer (usually purple) before applying the appropriate CPVC cement (usually orange). The colors don't matter, but makes it easy for the inspector to see if you used the appropriate solvents. It also helps you to visually double-check you didn't skip a fitting anywhere (it happens).
Anthony
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I think you are remembering incorrectly, at least in these parts. PVC is widely used indoors. The purpose to CPVC is to support higher temps of hot water. What would the point be to restrict PVC from being used for water inside?
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HerHusband wrote:

Thanks. I think PVC is allowed for indoor cold water lines where I am located (New Jersey). But, I'll double check that to be sure.

I agree.

I think I also read that on the Charlotte brand piping website, and it makes sense to me.

I did find those transition unions at places like Home Depot and Lowes and I think that's what I am going to use. They come apart so the copper/brass side can be soldered to the existing copper pipe. Then the CPVC or PVC side gets reconnected as you described and the threaded fitting tightens down on the rubber gasket.

I did see the ratchet-type CPVC/PVC pipe cutters when doing Internet searches. I'm going to get one for sure. I will be using 1" for each of the 3 supply lines, then branching off to 3/4" and 1/2" piping where appropriate. I am guessing that the ratcher/cutter tool may not be a good idea for the 1" lines due to the possibility of cracking the pipe while cutting. So, I'll probably use a tubing cutter or saw/Sawzall for the 1" pipes.
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RogerT wrote:

i've used a ratchet type scissors on 1" pipe ok.
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Roger,

After reading the replies to my post, I had to look it up in my old "Code Check Plumbing" manual (I recommend you get the latest release of this reference book!).
PVC is permitted for "Service" lines (underground supply coming into the house), but NOT for interior distribution.
CPVC is allowed for all situations.
My Code Check book is a few years old now, but the codes referenced are:
[IRC T2904.4.1] and (UPC 604.1)
I also found a few discussions mentioning this limitation with a quick Google search:
http://www.nachi.org/forum/f22/cpvc-and-pvc-16677 /
http://www.homerepairforum.com/forum/plumbing/3417-pvc-pipe.html
http://www.nachi.org/forum/f22/pvc-pipe-12663 /
I'm sure you could find additional references with more searching, but bottom line regular PVC is no longer allowed for plumbing runs inside the building.
Your local codes may override this, but from a practical standpoint it's easier to do everything with one type of pipe rather than stocking up on two different kinds of fittings.

I "did" use some female fittings years ago when I installed a washer hookup in a mobile home. No leaks at the time, but a year or so later the fitting cracked along the seam and caused water damage to the floor. Code or not, I learned my lesson not to use threaded plastic female fittings.

You can find the pipe cutters at Home Depot or Lowes, and most will work fine with 1" pipe also.
For larger pipe (i.e. 1-1/2" and larger DWV pipes) I prefer to use my power miter saw when possible to ensure a straight accurate cut. But, I made most of my cuts with a hacksaw as it was more convenient when crawling around in the crawlspace. Remember to remove the burrs from cutting with a knife before gluing up the joint.
Anthony
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HerHusband wrote:

Anthony,
Thanks so much. That is VERY interesting information.
I checked out the 3 links you provided and I did more searching for the actual codes. It looks like you are absolutely correct -- PVC is allowed for water supply --, but for water distribution WITHIN a dwelling unit, PVC is not allowed. From the links you provided, it appears that PVC for cold water distribution within a dwelling unit used to be allowed but now is no longer allowed.
I looked up the 2009 IRC online and here are 5 links to the actual code:
http://publicecodes.citation.com/icod/irc/2009/icod_irc_2009_29_sec005_par007.htm
http://publicecodes.citation.com/icod/irc/2009/icod_irc_2009_29_sec005_par010.htm
http://publicecodes.citation.com/icod/irc/2009/icod_irc_2009_29_sec005_par017.htm
http://publicecodes.citation.com/icod/irc/2009/icod_irc_2009_29_sec005_par018.htm
http://publicecodes.citation.com/icod/irc/2009/icod_irc_2009_29_sec005_par035.htm
One caveat is that this 2009 IRC says it is for One and Two-Family residential dwellings. Mine is a 3-Family. I haven't found a specific code yet for that, but my hunch (hope) is that using all CPVC for what I am doing will be okay.
I also haven't found the exact UPC 604.1 online yet, but one of the links you provided quoted from that and it said the same thing about CPVC being okay and PVC not being okay for water distribution within a dwelling unit.
So, I'll still be doing some more checking online, but I can see for now that using PVC will not be allowable for the water distribution system.
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P.S. I just found the 2009 UPC online and it appears to be the same as the 2009 IRC regarding types of piping allowed for water distribution within a dwelling (that is, CPVC is okay, PVC is not). Here is the link:
http://publicecodes.citation.com/icod/ipc/2009/icod_ipc_2009_6_sec005_par004.htm?bu=IC-P-2009-000004&bu2=IC-P-2009-000019
RogerT wrote:

http://publicecodes.citation.com/icod/irc/2009/icod_irc_2009_29_sec005_par007.htm
http://publicecodes.citation.com/icod/irc/2009/icod_irc_2009_29_sec005_par010.htm
http://publicecodes.citation.com/icod/irc/2009/icod_irc_2009_29_sec005_par017.htm
http://publicecodes.citation.com/icod/irc/2009/icod_irc_2009_29_sec005_par018.htm
http://publicecodes.citation.com/icod/irc/2009/icod_irc_2009_29_sec005_par035.htm
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RogerT wrote:

http://publicecodes.citation.com/icod/ipc/2009/icod_ipc_2009_6_sec005_par004.htm?bu=IC-P-2009-000004&bu2=IC-P-2009-000019
Is this thing going to be inspected by whatever authority has authority over it? If so you better be getting with them before doing anything, they will probably require this job to be done by a licensed plumber, and the inspector would have the final say on what is and isn't allowed. What are you going to do with the old copper? It's up again and worth taking to the scrap dealer. http://www.barchart.com/charts/futures/HGZ10
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On Sep 18, 4:36am, FatterDumber& Happier Moe

Why doesnt OP not want to use PEX??
Its cheap, easy to work with, going with all home runs from fixture to manifold means theres no fittings buried in walls to leak. ands all home runs makes isolating a problem easy......
PEX has no downsides and all advantages:)
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snipped-for-privacy@aol.com wrote:

I was originally planning on using PEX. But, in this case, I decided against it.
The way the layout is set up, it turns out that it wouldn't make sense to try to do manifolds and a home-run type of setup. One reason is that the existing plumbing goes up through the walls etc. to each apartment and it wouldn't be practical to try to do new home runs to each fixture.
It also turns out that the cold water coming into the property is in the front of the building and the utility room where the 3 hot water heaters and 3 boiler/furnaces are located is in the back of the building. And, all of the fixtures for each apartment are in the middle. So, rather than running the supply from the front to the back, and putting in 6 manifolds there (3 hot and 3 cold) for home runs, I decided to use a more traditional plumbing layout.
And, another reason for not using PEX is that there are some sharp turns required in a space where PEX bends would not fit. And, if I did the PEX with fittings etc. to make the turns, the cost of all of that would be a lot more than just using CPVC pipe and CPVC fittings.
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On Sep 18, 4:36am, FatterDumber& Happier Moe

Your original idea about using all cpvc is ok. I have used the sharkbite connectors and have not had a problem. They are expensive but I used a couple in a situation where I had to transition from cpvc to pex. It would save you from having to do any soldering. Otherwise I would go with a solder on female threaded coupler and a male pvc threaded coupler. It's better to make the cpvc side male.
If you plan on getting this inspected I suggest you take some pictures. Draw out what you plan to do and make a materials list. When you pull the permit go first thing in the morning and see if you can meet with the inspector. Don't wait until later in the day as they will all be out. That way you will find out right then if they are going to have a problem with you using cpvc.
As to copper I would probably do what you are planning with copper myself. I'm guessing you have one large hot water heater and you plan to switch to three smaller hot water heaters? Are you switchng to three meters as well? If all this is happening in one general area of the basement then the copper is not going to cost you that much. I have a house and a condo with copper and another house with cpvc. I have continued to use the existing material in each. Meters are pretty cheap on ebay if that's in your plan btw.
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