Copper vs PEX Repiping: Cost, Lifespan & What CA Homeowners Pick
When a house needs a whole-house repipe — after repeated slab leaks, failing galvanized or polybutylene pipe, or chronic pinhole leaks in aging copper — the first question every plumber will ask is: copper or PEX? Both are approved under the California Plumbing Code, both can last 50 years, and both have passionate defenders. The right answer depends on your budget, your water, and your house.
The case for copper
Copper is the incumbent: rigid metal pipe, soldered or press-fit joints, a track record going back generations.
- Proven longevity — 50+ years is common with non-aggressive water.
- UV and rodent resistant. Copper doesn't degrade in sunlight and rodents can't chew it — relevant for exposed runs and crawl spaces.
- Naturally biostatic and impermeable to outside contaminants.
- Handles high heat without derating, and looks tidy where exposed.
Its weaknesses: materially higher cost (copper is a commodity metal with volatile pricing), labor-intensive installation, vulnerability to pinhole corrosion in certain water chemistry — a known issue in parts of California — and theft appeal at construction sites.
The case for PEX
Cross-linked polyethylene has become the default for most repipes in the last two decades, and for good reasons:
- Lower cost — both material and labor. Flexible tubing snakes through walls and joists, meaning fewer fittings and dramatically fewer drywall openings.
- Corrosion-proof. Hard or aggressive water that eats copper doesn't touch PEX — a real advantage in much of the state.
- Freeze-tolerant. PEX expands rather than bursting — useful in mountain and high-desert zones.
- Quieter — it damps water hammer noise.
Its trade-offs: it must be protected from UV light, rodents can chew it, and some fitting systems have had recall history in past decades — a reason to insist on quality brands and an experienced installer.
What a whole-house repipe costs
In California, a full repipe of a typical single-family home runs $4,500-$15,000+. PEX generally lands in the lower half of that range and copper in the upper half; the spread also depends on square footage, number of bathrooms, one story vs two, and how much of the house has finished walls versus accessible crawl space or attic. Our repiping cost guide breaks down pricing by home size and material. Two line items homeowners often forget:
- Permits and inspection. A whole-house repipe requires a plumbing permit in California, with rough-in inspection before walls close. A contractor who suggests skipping the permit is telling you something about how they work — walk away.
- Drywall repair. Repipe crews cut dozens of access openings. Most repipe quotes include patching but not texture-matching and paint; some don't include patching at all. Ask exactly where the quote stops, because finishing drywall separately can add $1,000-$3,000 — and matching a hand-troweled texture is a skill in its own right.
Also confirm the quote covers new shutoff valves at every fixture and a fresh main shutoff — small items that make a big difference the next time anything leaks.
How to decide
For most California homes, PEX wins on value: lower cost, immunity to the corrosion that caused the problem in the first place, and faster, less invasive installation — a full repipe often takes just 2-4 days. Copper still makes sense when exposed runs need UV/rodent resistance, when local code or an HOA prefers it, or when you simply want the metal system and the budget allows. Many plumbers run copper stub-outs at fixtures with PEX in the walls — a sensible hybrid.
The best move is to get quotes for both materials from the same job description and compare line by line. Post your project on Plumber Comparator and request your free quote — licensed repipe specialists in San Jose, Los Angeles, and across California will respond with real numbers for your house.
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