Plastic Plumbing

The "C" in CPVC is the handy mnenomic that I use to remind myself "for cold water only". I don't know much about the PEX designation, but I've used stock schedule 40 PVC for years, just don't run it directly from your water heater due to the heat from the flue rather than the water. A quick Google check on PEX reminds me that it is a flex tubing, which may or may not be the one which was the source of a number of liability suits recently from its use n mobile homes. Sharkbite fittings are great, though, although perhaps more suited for repair applications than what is essentially a build-out.

Although it seems counter-intuitive, rigid pipe is easier to run than flex - think of trying to push spagetti.
Hope this helps.

ktel60,

The other flexible piping you mention was PB or polybutylene. It came with a good prognosis, but ended up with more problems than it was worth. I believe that the post from Water Buffalo corrected your error in the "C" of CPVC.

I think the determining factor will be the possibility of freezing. If there is ANY possibility, then PEX is much superior to CPVC. With PEX one can purchase manifold assemblies with individual shut-offs for each branch line, to allow the separate drops for each fixture.

--John M.

Hi,

My recolection of the situation was that the problem was not with the polybutylene pipe its self, but with the 'o'ring seals used to join it, that ended up failing far too often, resulting in lawsuits. Poly B as we used to call it therefore fell out of favour.

PEX has been used successfully here on hot water service up to 60degC: the pipe route for extending the services to a new utility room and a new bathroom involved putting both the hot and the cold pipes inside a vertical box that already contained the soil pipe, and routing them below floor level in the services void. The route dictated that a flexible piping system was the only realistic possibility for installation, thereby avoiding extensive rip-out, rebuild and redecorate operations. 20mm Ø blue underground water supply pipe (the UK reader will be familiar with this) and its hand-tightening compression fittings worked a treat. It comes in a big coil. It can be insulated with 22mm Ø slip-over pipe lagging, looking a bit like an elephant's trunk when completed.

Remember that the first few metres of pipe coming off the outlet of the central heating boiler really ought to be metal, not plastic, as the temperatures to be withstood are higher than 60degC.

No problems with either material as regards corrosion resistance to low pH water, though if it's really that low, it really ought not to be drunk - one's teeth will be the first things to deteriorate....

"And I'm not a plumber!"

Be advised that the system will almost certainly have to meet a local building code, and this may include a licensed plumber to install the piping, and it will have to pass an inspection. Unless you:

1) live far enough off the grid that you pipe in sunlight (it IS well water after all, not city water, so that's possible) or;

2) are scofflaw enough to not give a good sharp rap about code requirements (badgers? we don't need no steenking badgers!)

HI There,

PEX is DEFINATELY the way to go.

AQUAPEX is the best of the bunch if you can get it (readily available here in Canada)

There are many diffferent types of PEX and not all are equal, or interchangable for that matter.

I have recently redone my entire 60 year old house, ripping out galvanized steel pipeing (Yikes!) and replacing with PEX.

The Aquapex system uses a tool to expand the pipe end (with a pex sleeve over it) which you then push onto the fitting (your choice of brass or plastic) and let it contract (about thirty seconds) onto the fitting, Voila!

I personally would never use a crimp pex connection, as I would always have doubts about the crimp ring (just an irrational fear I guess)

The Aquapex is rated for close on 100 years in normal use. Freezing does not affect it (the fittings may be another story however), and if you kink it, no problem, you just heat (gently!) with a blow torch until it goes clear and then allow it to cool.

I hope this doesn't sound like I sell the stuff (I don't!), but I used to work in a plumbing supply wholesale, and the plumbers loved it; quick, easy and NO callbacks!

My personal experience with it was the same. As noted in previous posts, you should not connect it directly to the hot water outlet of your hot water tank, I used an 18" copper flexible connection and have had no worries.

The only drawback, the expansion tool is REALLY expensive to buy, so I just rented one from the place I bought the piipe and fittings.

Good luck!

I just happen to be a plumber and I think you would be OK with either type of pipe. I would assume your house currently does not have a manifold system. (That's the method you are describing of running uncut lines to each fixture.) Are you trying to avoid cutting and patching walls? Since the house is small I would think it would be fairly simple to remove the old copper and directly replace with new CPVC. BTW The 'C' in CPVC stands for 'chlorinated'. It is suitable for domestic hot water piping. The CPVC is very simple to install even for a novice and is what I personally prefer. Without knowing the specifics of your particular situation it's difficult to advise you further, but I am happy to help in any way I can. You can post to this thread or PM me. Do you live in the US? What state? How old is your house? Have you looked at the relative cost of a treatment system to neutralize the pH so you won't have to replace your existing piping? Just a few questions I would ask a prospective customer.

Thanks to everyone for their helpful advice----I'm going PEX. Must tear out several ceilings, but it will be a learning experience! Tried an acid neutralizing chemical injected by pump, but I think the cure was worse than the problem, the chemical was sodium hydroxide! ClintB

PEX is a good choice if you own the home but if you intend to sell the structure use CPVC for both hot and cold water with a pressure fitting wher you connect to the copper piping. The reason for using CPVC is due to cosmetic appeal. A floppy hose vs. a structured bend is preferred by potential buyers. Also when a leak develops a small piece of pipe and a connector will solve the problem, but with PEX you have to replace the entire water line.

I hope this helps, If you need further assistance please e-mail me at:

BLACKSCORPION908@YAHOO.COM