PVC/CPVC – rigid plastic pipes similar to PVC drain pipes but with thicker walls to deal with municipal water pressure, introduced around 1970. PVC stands for polyvinyl chloride, and it has become a common replacement for metal piping. PVC should be used only for cold water, or for venting. CPVC can be used for hot and cold potable water supply. Connections are made with primers and solvent cements as required by code.
If you decide to try this job yourself, be prepared to keep meticulous track of about a dozen tiny parts (put the stopper in the sink so none of them fall down the drain). There are many different faucet designs, so you may not be able to tell what to replace until you've done the disassembly. Whether you do it yourself or hire a plumber, this would be a good time to think about whether you want to upgrade the faucet with a new design.
I was disappointed with the pressure of a tub and shower that were plumbed with 1/2 supply lines (2nd floor). Could be low pressure from the street, but I want to replace with 5/8. Plus, I'd like to have 2 back to back showers, one inside and one outside. So, I had intended to bring a 1 supply to both, then branch up to valves and shower head with 5/8. Finally, I thought pressure from the street was typically 55 to 70 psi and I am concerned if pvc can take that.Any thoughts?