PEX is my favorite tubing to snake through floor joists and other areas where many couplings would be required if CPVC or copper were used. This article is about a hybrid water supply system. In this article I will explain how PEX can save lots of money and provide a better water supply system when it is used in a hybrid system (a mix of PEX and CPVC or copper).
In this article, I will not focus on copper. Because of extremely high cost and because copper seems to degrade faster than CPVC or PEX. I think people should avoid using copper pipe, tubing and fittings.
For money conscious people, CPVC can save lots of money on labor and material. Rigid CPVC pipe seems to be a reasonable choice to save money and dramatically reduce risk associated with defective installation (improperly installed crimp rings or other connections).
I think flexible CPVC tubing (because of its thin wall) is risky. Also, as CPVC becomes brittle, it might not be possible to add a tee in the future (tie in for a new bathroom at a later date). PEX tubing’s thick wall makes it a good choice where flexible tubing is needed. Also, adding a tee fitting in the future should be safe. I recommend using PEX where flexible pipe can save money and provide a better system by reducing the number of fittings.
A hybrid system combines the simple, low cost CPVC glue joints advantage with the reliable flexibility of PEX. CPVC fittings are extremely cheap-but-rigid pipe requires many short pieces (and couplings) in tight spaces. Snaking PEX to areas where lots of fittings are necessary (like bathrooms) and then switching (adapting) to CPVC saves lots of money.
For people that worry about improperly installed crimp rings or other connections, a hybrid system dramatically reduces the risk of defective workmanship. Very few or no crimp rings are required with a hybrid system. Push-fit fittings can provide a fast transition from PEX to CPVC (or copper). Even if installers use crimp ring type adapters, the number of crimp rings is dramatically reduced.
Some people worry about CPVC getting brittle as it ages. Many years down the road, if bathrooms are replaced, PEX snaked to bathrooms will provide a brittle free transition to new pipe for a new bathroom. [Note: Kitchens and laundry rooms might be all PEX.]
Properly glued CPVC joints supplying water to fixtures are reliable and last a long time. Bathrooms require many tees and fittings. Bathrooms can be piped out extremely fast using CPVC pipe and fittings.
PEX tubing properly snaked through a home can provide an excellent low cost supply of water to each bathroom, kitchen and laundry room.
PEX and CPVC require proper installation and testing. To prevent dangerous situations, pre-mature failure, noise and other problems always focus on details concerning local codes and manufacturer’s specifications.
If I can use my forty three years of plumbing experience to help educate you and help you focus on details, you will make better plumbing decisions.
PEX vs Copper - Comparing plumbing pipes
PEX vs CPVC - Comparing plumbing pipes