[Hugh R]

What will the City of Orange permit? Do a permit if you ever want to sell. I'm guessing you have galvenized based on the year of the house. Look at the underslab versus overhead piping. When my house was repiped the underslab was abandoned and pulling the overhead piping out and using the same holes to fish new copper was not difficult. If you use copper consider the "K" commercial grade, don't use the really cheap stuff. Pick up a piece of the three grades at Home Depot and heft it and you'll see the difference.