Several years ago, I was getting ready to take a nice bath, but my home had other ideas for me.
After a morning of gardening, I was ready to relax and soak until my fingertips turned into prunes. Book to read? Check. Bath pillow for my head? Check. Bubble bath? Check.
I felt my muscles begin to relax as I lowered myself into the warm, soapy water. I picked up my book and let the water soothe me as it ran.
Moments later, after turning off the tub faucet, I was surprised to hear the sound of water rushing inside the wall. Oh, no! Luckily, I had my wits about me, and I scrambled out of the tub, verified the sound was coming from the back side of the faucet wall, and ran outside to shut off the water at the meter.

PEX piping comes in red (hot water) and blue (cold water). The small gray pipes are the stub ends of the polybutylene piping, which ran through the concrete slab floor.
Today, almost $5,000 out-of-pocket later, and with a new shut-off valve installed inside the house, I am happy to report that my 40-year-old home (at the time) has brand new water supply piping. And, I’m that much wiser about plastic piping and what home insurance doesn’t cover.
Polybutylene pipe, also referred to as PB or Poly-B, is a light gray colored pipe (sometimes seen as blue or black) that was used between 1978 and 1996. Along with the more well-known (and less problematic) PVC pipe, it was used instead of copper or cast iron, especially at fixtures. I’m sure it was used in many other homes in Tampa Bay and Florida, too.
What they didn’t know when they were installing it, is that Polybutylene has the tendency to fail without warning. No leaking, no dripping, no lower water pressure. It just suddenly bursts. And in my bathroom, as we found out, there was a one-inch slit in the pipe nearest the tub valve, and it split similar to how a pea-pod splits open.
Luckily, I was right there when it happened, and immediately cut off the water supply. With a tile floor over a concrete slab, I had minimal clean-up. (Of course, I finished my bath first, because, why not?)

New PEX under the cabinets – red for hot water (with dark gray insulation) and blue for cold water. You can also see the original piping still in use: PVC plastic piping for the sink drain and ventilation, the copper pipe leading to the toilet, and the braided stainless steel hoses connected to the sink faucet handles.
In between calling plumbers to get quotes, I researched the options I had and decided to contact my Home Insurance agent. Surprisingly, they didn’t cover the problem or the solution, even though this is a known problem for Polybutylene pipes. (They would have covered the water damage to my home & furnishings.) Moreover, now that I had confirmed that my house contained the pipe, it was my responsibility to replace all of it, not just one pipe. I was left to ponder the definition of insurance.
Back to the options: my choices were really PVC or PEX, and I chose PEX. PEX is short for cross-linked polyethylene, and it’s used in Europe a lot. While PVC (polyvinyl chloride) comes in straight piping lengths, PEX can bend, and that is an advantage in an existing house. Be sure your plumber is experienced with this type of pipe, as there are different types of fittings to connect the pipes to fixtures than those used with PVC.
While the existing water supply lines were laid under the concrete slab, the new ones are placed inside the attic. They are red (hot water) and blue (cold water) and I made sure they were insulated both in the attic (they’ll get too hot) and in the house (to maintain the temperatures). The plumbers were able to climb through my attic to lay the new piping and only cut out one square hole in the bathroom ceiling to help fish the new pipes through the attic and down the interior walls. The only place they couldn’t reach from the attic was the kitchen sink, so they wove it through the backs of the base cabinets.

New PEX through the attic is covered with pipe insulation and attached to the wood trusses.
The PEX now runs from the water meter in my front yard, into and throughout the whole house. The plumbers also replaced the outdoor hose bibs, and I was able to move 2 of them (within reason) to more convenient places. They removed the old polybutylene pipes, which stuck out of the concrete slab inside the walls, too.
The whole re-piping took about a day and a half, not counting the drywall repair later. If you work from home, be sure to make friends with your neighbors beforehand.
Overall, I am glad I was able to replace the Polybutylene pipe with PEX, and I would use it again in my future Forever Home. The new pipes definitely give me peace of mind every time I take a bath.