CPVC pipe to shower valve

[MiamiCuse]

I am redoing the run from my shower valve to my shower head on the pool side shower.

Originally it was all copper pipes in and out. However, the copper pipe from the shower up the exterior wall, then a 90 degree elbow, then three feet along the soffit is exposed piping. Now that I have the inside sheet rock removed for other work, I am thinking of removing the exposed copper pipe and run the pipe to the inside wall from the shower valve, and up and over on the inside of the wall and above the soffit, so the entire pipe run would be concealed.

Originally, the copper pipe was soldered to a coupling that has a stub on one end and 1/2" male thread on the other end. I cut the copper pipe and unscrewed the coupling. So now the top of the valve has a 1/2" female threaded outlet.

I am thinking of using CPVC pipe instead for this concealed run. It's code approved and a lot easier than copper with no need to solder. I will do all the fittings using CPVC fittings except at the end of the run I will probably use a sharkbite drop ear 90 to secure the CPVC to a piece of wood for a ceiling mount shower arm. How would I connect the shower valve to CPVC pipe? Do I need some coupling to go from a female threaded 1/2" to CPVC? Is there a sharkbite coupling that does that or a special CPVC coupling that does that?

Thanks,

MC

[Bob F]

There is a fitting just for this. It is an ell with female thread on one end, and a stub of CPVC on the other, and has "ears" for mounting. Do not use a CPVC part for the threads. It need to be metal.

[MiamiCuse]

Thanks! I will go look for it. Much appreciated.

MC

[HerHusband]

MC,

I used CPVC when I plumbed our house. When connecting to valves and other fixtures, I used a "transition fitting". Basically, it's a brass fitting on one end, a CPVC fitting on the opposite end, and a gasket that gets sandwiched between the two halves (held together with a threaded coupling). The gasket is supposed to allow for the different expansion rates of the two materials, but I don't know if there's any truth to that. They're not cheap, about $5-10 each, but well worth it.

Here's a link to the type I used:

These days I've been seeing a molded transition fitting, where the CPVC fitting on one end is molded around the back end of a brass fitting. I used these at my in-laws house, but I don't know how they compare with the gasketed type.

In my case, the shower valve was not threaded, so I had to solder in a small stub out to use with the transition fittings. I did that out in the garage before I installed the valve, so I didn't have to worry about the torch in close quarters. So, you have an advantage with a threaded shower valve body.

There are also brass drop-ear transition fittings. It's a brass elbow with ears you can secure to a wood block, with the same gasket and CPVC stub on the bottom.

Here's the type I used:

I used the transition elbows for the shower head, tub spout, and for all the shutoff valves in the house. I mounted the elbow and stubbed it out through the drywall with a small brass nipple (usually around 2 to 3 inches long). Then I used threaded shutoff valves.

CPVC is great to work with, but it won't hold up to situations of physical stress. So the brass transition elbows are much more secure than a CPVC drop-ear.

Anthony

[Alta47]

As others have said, you can buy an adapter that has a threaded copper end and a CPVC-compatible other end to make the transition.

Also, you can probably find a place the secure the CPVC pipe itself to a joist or stud using an ordinary metal bracket that is used to secure pipes to walls and ceilings. You probably don't need a dog-eared fitting.

[MiamiCuse]

Thanks. I saw one of those at HD, actually I I guess I could use either a CPVC fitting, like the one on the bottom there:

or a sharkbite fitting, with a FPT connector on one end and a standard push-fit on the other end.

MC

[HerHusband]

MC,

I bought all my transition fittings at Lowes, but the last time I looked they were only carrying the molded type like your photo showed.

I have no idea how these compare to the gasketed type for long term reliability, but they are slightly less expensive. I've used both types and they all work great for transitioning from CPVC to metal fixtures.

Anthony