If you were to redo the plumbing in your house, would you use metal pipe or plastic pipe?
1.Polyethylene for water supply
2.Copper for water distribution
3.PVC for DWV (drain,waste & vent)
Why not just all copper?
In my opinion, as a homeowner rather than a plumber, I wish to hell my house had more plastic pipe. It's far easier to repair and can handle being flexed. Plus, it's much easier for a homeowner to handle putting in plastic pipe. I used Pex tubing on my kitchen faucet. SO easy to install. I wish I were brave enough to get a torch and some solder so I could fix the crap-a__ plumbing in my house.
The "Supply Pipe" is the direct burial pipe from the municipal water main or well to the structure. While copper certainly is well suited for this application copper has three drawbacks.
2. Hard drawn copper pipe is in 20ft lengths and annealed copper pipe is made in 60' rolls which means we would normally have to make one or more joints underground.
3 Under some adverse soil conditions copper pipe will corrode from the acids or alkali in the soil.
For these reasons I prefer to use continuous roll Polyethylene pipe which is commonly available in rolls up to 250' long, and in some instances 500' by special order. In this manner we can install a joint free pipe that has a proven track record of providing 50+ years of service.
"DISTRIBUTION PIPING" is the pipes within the structure that distribute the water from the house main to the point of demand. The alternatives here are Galvanized Iron pipe, Copper pipe, PEX tubing, CPVC Pipe(difficult to find and almost never used), CPVC-CTS tubing, and if your under the IRC you may use Polybutylene although with the number of failures and class action lawsuits against PB I don't understand why anyone would consider it. I have heard all the arguments in favor of PEX but in my region copper has shown to have a proven reliability of 75+ years (and most of that old copper is thinwall type M with lead solder joints.) It hard to beat a success.
"DWV" piping is the Drain, Waste and Vent (Sanitary Waste) pipes in your house. While they do make DWV grade copper pipe most homeowners would find it labor intensive and cost prohibitive for residential construction. The alternative here would be No-Hub cast iron pipe, PVC or ABS. Here again, most homeowners find No-hub cast iron to be cost prohibitive. The choice between PVC or ABS is generally a matter of choice or local code requirements but in the end, both have proven to be an economical and extremely reliable type of pipe for this application.