: I am remodeling a bathroom and found that my water supply lines are copper 1/2" throughout the house (both hot and cold

David,
The max you can run on a 1/2" line would be one bathroom. Even that is cutting things tight. For best performance, try to use 1/2 lines to two plumbing fixtures, and increase to 3/4" after that. A typical two bath home will have a water service from the meter of 1".

Increasing pipe sizing will improve water volume to the fixtures involved. As to whether to use CPVC or Copper, to me it depends on the available water supply. If the balance is correct, copper would be my first preference. In not, then I would suggest the CPVC. In the Seattle area, the City water is treated for longevity of use. Some of the local well water systems are best done in the plastics.

Regards,
Terry

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