Copper is not without its disadvantages: it's outrageous expensive as of late, soldering can be dangerous (banned in some cases due to fire risk), it takes longer to install than most other options, and some water supplies have a composition that leads to premature failures.
PEX is a universe of options: PEX-A, PEX-B, crimp rings, clamps, plastic/brass fittings, etc. It also needs to be properly installed - PEX B has very specific locations for the crimp/clamp rings on the fitting, and the difference between a proper crimp/clamp and a failure waiting to happen is very subtle.
Just my personal opinion, that's the problem with US housing. We build stuff to last 20-30 years(if properly installed) , instead of 100s of years.
Well obviously, if we don't build houses to last longer than a few decades. You're describing a symptom not a reason.
My house is typical for a house its age. I have no idea what people will want from a house in 2073, but it will be at least somewhat different from today. Some of that will be style of course, but some will be real functional differences.
My point is that it's possible to build a house with with a lasting structure that can be updated for new technologies as they arise relatively easily, but we don't do that because the home building industry is overrun with corner cutting.
If you visit old houses (pre-war) you can see that the general quality of the construction is just considerably higher than the crackerjack boxes we've been erecting since the '50s. Sure, there is an element of survivorship bias, and some of the legacy stuff is ugly to deal with (lead paint, asbestos, horsehair, and knob and tube, I'm looking at you), but overall they were built to last in a way that new construction today just isn't.
Sure the old houses looked stronger, and and often were in places where strength is not needed. However they often are lacking in critical areas.
Floods generally will not destory a house structure but it will destory the drywall, carpet, and the like so the cleanup is expensive.
No need to worry about incorrect crimps and it just works.
If you consider push-to-connect fittings acceptable, something like this could be very nice for connecting tubing to shower valves:
https://www.johnguest.com/us/en/cts-fittings/prolock/threade...
(3/8” is permitted by code, but not by the tables in the UPC - actual math is required.)
[0] PEX, unlike copper, tolerates fairly high velocity hot water. Copper has a delicate passive layer on the inside, and scrubbing it off will erode the pipe. The interior of a PEX pipe, is, drumroll please, just PEX, which is a rather tough polymer that is not going to be easily eroded away.
For domestic hot water, for the connection from whatever part of the system stays hot (the header, the recirc loop, etc) to the fixture, the amount of time and wasted water needed to get hot water to the fixture is directly proportional to the volume of the interior of the pipe, and for a fixed length of pipe, it’s inversely proportional to velocity. So you want the narrowest pipe you can get away with. 3/8” PEX has about half the interior cross-sectional area as 1/2”. This means you get hot water about twice as fast. 3/8” PEX loses about 26 psi/100 ft at 2 gpm and much less at lower flow. If you have 40 psi water and you have a short-ish pipe, that’s usually fine. Or if you have higher pressure and a longer pipe, you’re still fine.
The issue here has that, while the 3/8” PEX is near-perfect for this application, the rest of the system is not amazing. Your sink is likely (sigh) “3/8 female compression”, aka non-standard 9/16 UNEF or so, but the flow rate is well under 2 gpm, so this isn’t a big deal - use whatever adapter you like.
But your shower likely has 1/2” NPT brass female threads. To get the benefit of 3/8” PEX, you need to adapt it at the shower.
> If needed anything that required the 3/8 in, I would just use copper because it’s likely a very small and isolated case.
No, don’t do that. From the horse’s mouth (this particular horse very much wanting you to use copper):
https://copper.org/applications/plumbing/cth/design-installa...
> [Copper Pipe] Water Velocity Limitations
> To avoid excessive system noise and the possibility of erosion-corrosion, the designer should not exceed flow velocities of 8 feet per second for cold water and 5 feet per second in hot water up to approximately 140°F. In systems where water temperatures routinely exceed 140°F, lower flow velocities such as 2 to 3 feet per second should not be exceeded. In addition, where 1/2-inch and smaller tube sizes are used, to guard against localized high velocity turbulence due to possibly faulty workmanship (e.g. burrs at tube ends which were not properly reamed/deburred) or unusually numerous, abrupt changes in flow direction, lower velocities should be considered. Locally aggressive water conditions can combine with these two considerations to cause erosion-corrosion if system velocities are too high.
A 2.2 gpm shower head fed by 3/8” copper is out of spec.
I have personally seen copper tube fail when used with plain water at excessive velocity. It’s not pretty. Fortunately it was outdoors. Don’t do this inside your walls. Most vendors seem to think 8 ft/sec in PEX at 140F is fine, though.
Can you elaborate on this please?
It takes 90 seconds for hot water to flow from my water heater to my kitchen in the winter. I’m not sure if I have 1/2 or 3/8 pex (I’d have to crawl under the house to check). I’ve been thinking of adding a small Bosch water heater under the sink or a recirculation like, but maybe I should reduce the size of the pipe too
But they don't list all possible pipes, or all lengths. And the argument is that 3/8 PEX will flow to requirements and have a smaller amount of water sitting in it.
Back in the day all us kids knew to get the ABS stuff when building our potato cannons. I was terrified of the combustion chamber shattering right next to my face.
I guess the pro move is to either (1) fully characterize the amount of pressure made from a random shot of hairspray, then choose a PVC pipe to accommodate, or (2) put a larger ABS sleeve over the inner PVC combustion chamber to contain the shrapnel.
This should be repeated every year.