Andrew,

I'm rehabbing a bathroom on the second floor of my old house in
Philadelphia, and I'm running all new supply lines. I'll be tapping
into copper in the basement, and I have a wide open chase to get to
the second floor. What should I run? Copper is getting awfully
expensive these days, and I'm curious about the cpvc and pex.

When we built our house a couple of years ago, I chose CPVC for our hot
AND cold supplies, for a variety of reasons:

It's inexpensive.

It's readily available just about everywhere, including mom and pop
hardware stores. You'll be thankful for that if you run out of supplies
near the end of your project, or if you need to make an emergency repair
in the future.

It's lightweight. A big plus if you're crawling around in a crawlspace or
an attic. Much easier than dragging a large coil of PEX around.

It's highly resistant to acidic or other poor quality water conditions.
Copper can sometimes get pinhole leaks.

It only requires a few basic hand tools to install. PEX requires an
expensive crimping tool to install the fittings.

It takes very little practice to learn how to make professional quality,
leakproof, connections. Copper requires a bit of "skill" and experience
to achieve attractive and waterproof joints.

There's no risk of accidently starting a fire since no torch is needed.
However, be careful with the solvent fumes in confined spaces.

It's widely accepted by most plumbing codes. So you shouldn't have any
inspection problems even with the "old-timers".


The only "gotchas" you may want to be careful of a

CPVC expands in length with temperature, so try not to make long
continuous runs over 20' or so. Add a bend or two in long runs to allow
some expansion.

CPVC (and most plastics) don't hold up to "stress" applications very
well. So avoid CPVC valves and use the appropriate brass drop-ear elbows
at all your fixtures. The best ones have a gasket between the brass and
CPVC parts of the fitting to accomodate the different expansion rates.
Expensive (about $5), but worth it.

DO NOT use a female threaded adapter made of CPVC. They're against code,
and I know from personal experience they will crack. If you need to adapt
to another pipe, only use MALE threaded CPVC adapters (the female adapter
would be on the copper, Galvanized, or whatever). Or better yet, use an
adapter made specifically for the purpose.

Anthony