Two good materials, different trade-offs
Most repipe conversations in Fullerton come down to copper or PEX. Copper is rigid metal pipe that has been used in homes for generations. PEX is cross-linked polyethylene, a flexible plastic tubing that has become common in new construction and repipes. Neither is automatically the right answer.
What usually decides it is the house. A single-story slab home with an open attic suits either. A two-story home with finished ceilings may favor PEX because it can be fished through walls with fewer openings. Some owners simply prefer copper, and some plumbers are more experienced with one than the other. A careful installer matters more than the label on the pipe.
Side by side
Copper
- Rigid pipe joined with soldered or mechanical press fittings at every turn.
- Long track record in homes; tolerates heat and sunlight.
- Usually needs more and larger wall openings to route.
- Can develop pinhole leaks after many years, especially with aggressive water or high velocity.
- Comes in wall thicknesses such as Type L (thicker) and Type M (thinner).
PEX
- Flexible tubing that bends around corners, so fewer fittings.
- Often routed with fewer, smaller wall openings.
- Must be kept out of sunlight and away from high heat sources.
- Joined with crimp, clamp or expansion fittings depending on the system.
- Often color coded red for hot and blue for cold.
Questions that tip the decision
| Question | Leans copper | Leans PEX |
|---|---|---|
| How many finished walls must be opened? | Few, or access is easy | Many, or you want fewer openings |
| Is the route through a hot attic? | Either, if insulated and supported | Either, if protected from heat and sunlight |
| Do you have strong preferences about plastic in the home? | Yes | No |
| Are lines exposed outdoors or in sun? | Copper handles exposure better | Needs covering or a different material there |
Terms you will hear
- Type L / Type M
- Copper wall thicknesses. Type L has a thicker wall than Type M. Ask which one is quoted.
- PEX-A, PEX-B
- PEX made by different manufacturing methods. Each is paired with specific fitting systems.
- Expansion fitting
- A PEX joint where the tubing is expanded over the fitting and shrinks back to seal.
- Crimp or clamp ring
- A PEX joint sealed by compressing a metal ring around the tubing and fitting.
- Manifold
- A central block that feeds individual lines to fixtures, sometimes used in PEX layouts.
- Press fitting
- A copper joint sealed with a pressing tool instead of solder.
Ask before you choose
- Which material do you recommend for this house, and why?
- For copper: Type L or Type M, and soldered or press fittings?
- For PEX: which type and fitting system, and is it rated for potable water?
- How will lines be supported, insulated and protected in the attic?
- What connects the new lines at the water heater?
Common questions
Is PEX allowed for drinking water in California?
PEX is used for potable water in California homes when it is listed for that use and installed to code. Ask your plumber which product and fittings they use and check with the city on any local requirements.
Is copper quieter than PEX?
Flexible PEX can dampen some water hammer noise, while rigid copper can transmit it. Proper support and, where needed, water hammer arrestors matter more for either.
Can a house have both?
Yes. Some repipes use copper where pipe is exposed or near heat and PEX elsewhere. Transitions should use fittings designed for that connection.
General information for Fullerton, not a quote or professional advice. In an emergency, call 911.