Several years ago, we had a second floor put on our house, and the plumber used PEX tubing for nearly all of the plumbing. For the most part, I’m quite happy with it. The PEX that feeds the forced-hot-water baseboard heat is stapled to the underside of the first floor’s joists, then snakes through the back of a first floor closet to feed the convectors in half of the second floor. When that zone calls for heat, the hot water flowing through the tubing causes it to expand, it looks as if there is a 50% increase in length given the “S” shape that the tubing assumes. As it expands, it creaks and pops through the staples under the floor, and contorts itself through the walls, making a surprisingly loud crackling sound as it does so.
My wife has “had enough” of the noise, and has given me the mission of “making it stop.” I could attempt to switch the PEX to copper, but it is quite a long run and I’m not keen on the investment, given today’s copper prices.
I have seen (both in the stores and on television) a newer version of PEX that has an aluminum tube along with the plastic. The price seems to be comparable to “regular” PEX, does the aluminum PEX have similar expansion issues as the old style, or does it come with its own noise issues?