I am plumbing an addition to my house and would like to know the advantages/disadvantages of putting copper in the walls vs. pex. We are doing the rest with pex.
PEX meets code, is used extensively by production home builders and is growing in acceptance in the housing industry. Having said that, I would use copper. I know as a matter of fact copper will last a hundred years, probably much longer but I don't know that as a fact, if not subjected to radically altered water or physical abuse. PEX is usually warranted for 30 years but I have been bitten by several warranties in the past. I just built a 3400 SF home myself and sweated copper for all water supply lines.
just re did my whole house with Pex and did extensive research on copper vs Pex and chose Pex hands down. Ease of installation COST that was a big on I saved over half. As far as specifically in the walls I guess one could argue it could be pierced by a nail easier but then again so can copper just not quite as easy. Other than that all my wall runs were continuous with no joints as apposed to copper in a tight area where you would have to piece it in or use coiled copper which is twice the cost ridged pipe. I say since you are going with Pex for the rest do it all. PEX has proven its self for years now. It is a pretty hot topic so I'm sure I you will get a wide variate of opinions from others.
Pex Plumbing Disadvantages
If you're already installing pex in the rest of your house, then there's no reason to change. I would be interested to see the research that shows copper will last 100 years. That would have to be with absolutely pure water running through it, or no water running through it. In our area, where the lime content is quite high, I repair at least a dozen in-wall copper line leaks, (usually a pin hole that corroded thru), each year. Most of these houses are less than 40 years old. I'd say Pex is the wave of the future.
The biggest disadvantage to copper is the price compared to pex. Also if copper freezes it will split. Pex can swell without bursting. It will however split at the fittings. The big disadvantage with pex is that the average homeowner does not have the crimping tools and they are very expensive to buy. The big advantages to pex are that it is very flexible and you can bend it around heat pipes and electric boxes without using alot of fittings. Also it is made 500' rolls, so if you wanted you could pull a separate piece for each fixture from the fixture to the basement with no fittings to leak behind the drywall. Just don't kink it while pulling it. Also with pex you don't have to worry about starting your wall on fire. You can also repair pex without having to drain all the water out. Cpvc would be the way to go if you have acidic water because it will eat the copper pipe and the brass pex fittings away. Good luck
