View Full Version : Replacing old-style PEX, from water heater to bathroom

03-14-2007, 12:51 PM
Hi there,

My wife and I recently began the renovation of a newly purchased 1932 home. Our inspector informed us that we had the "old style pex tubing" which runs from the waterheater etc in the basement across the house to the bathroom (about 40 feet away). He did say the copper fittings were a plus though.

I just figured since we're doing so much work under the house anyway (and we have the bath tub out, the toilet out, and the sink out), we might as well upgrade the plumbing.

We'd like to use PEX for the simplicity of it (or, so we're told).

Are there any do's and dont's you can think of? Any good reading online out there? Do we need special equipment or can we just use the connections that screw/couple?



03-14-2007, 03:55 PM
If you can rent the tools (yes, you need special tools to connect pex -generally, at least), or buy them then resell them on maybe e bay, then it's not too bad; they're expensive. If you are only going to be doing a few connections, then Sharkbite fittings could be used - these do not require tools to install, but they are expensive - probably 10x what a crimp connection costs (but you need to tools to install one of those).

What type of pipe is it really?

03-14-2007, 07:58 PM
It is probably gray polybutylene, not "old PEX".

03-15-2007, 06:17 AM
thanks for the responses!

the pipes that are in place now are gray, 3/4", and use copper fittings.

edit: yes, I think they are in fact gray polybutylene - just looked it up and that looks like what I have

I wrote down all of the information printed on them but I'm not sure which info is significant. At any rate, I see:

3/4" CTSX 7/8" O.D.
100 psi
B 137.8 potable tubing
Qest E PB 2110 4137
ASTM-D 3309

Anyway, my local hardware store will rent me the crimper.

my plan is to run new pipes from the water heater and source to the bathroom (I was told these should be upgraded). connections in the bathroom are shower hot/cold, toilet supply, sink hot/cold.

can I use the same cold water supply pipe to feed the shower, toilet, and sink? same hot water line to feed the shower and sink?

which fittings are recommended and is there anything I should consider that I may not be thinking about?

Thank you so much for your advice!


03-15-2007, 08:21 AM
ASTM-D 3309

Yep that the standard for Polybutylene


03-18-2007, 11:11 AM
I've been using the WaterPex fittings- perhaps a "Shark Bite" knockoff. So far they seem to be working great.

I decided to go this route versus crimping with a tool because the tools are way too expensive (about $100 for a tool that handles one size, $175 for a tool that will crimp both 1/2" and 3/4"), and the Water Pex couplings only cost a little more than the standard crimp couplings. (At least at the Lowe's near my house!)