Quick answer
Both are approved for home water supply. PEX is flexible plastic tubing that runs in long lengths with few fittings, so a repipe costs less and takes less wall opening; it tolerates freezing better than copper but must be kept out of sunlight and away from high heat. Copper is rigid, long proven, unaffected by UV, and tolerates heat, but costs more and can develop pinhole leaks in aggressive water. Most whole-house repipes today use PEX; copper is still common for exposed runs and near water heaters. Call (888) 217-6781 to reach a plumbing company taking calls in your ZIP.
Follow the short menu, then your 5-digit ZIP. The line goes quiet for a few seconds while it connects; stay on. If it does not connect, call once more: companies taking calls change minute to minute.
Written & reviewed by Marcus ReedIICRC WRT
Reviewed November 4, 2026· Next review May 2027
If you are repiping a house, replacing galvanized or polybutylene, or fixing a section, the choice usually comes down to PEX or copper. Both are approved for drinking water in US codes.
Side by Side
| PEX | Copper | |
|---|---|---|
| Material | Flexible cross-linked polyethylene | Rigid metal tube |
| Installed cost | Lower | Higher |
| Fittings | Few; long runs | Many soldered or press joints |
| Wall openings for a repipe | Fewer | More |
| Freezing | Expands; more tolerant | Splits more readily |
| Sunlight (UV) | Must be protected | Unaffected |
| Heat | Not right at a water heater outlet | Tolerant |
| Aggressive water | Not affected by corrosion | Can develop pinhole leaks |
| Track record | Wide US use since the 1990s | Many decades |
When Each Makes Sense
- PEX suits most whole-house repipes, especially in finished homes, because it snakes through walls with fewer openings and fewer joints.
- Copper suits exposed runs, basements where it may be in sunlight, and the first section at the water heater, where many codes and manufacturers require metal.
- Mixed systems are common: copper at the heater and exposed runs, PEX elsewhere.
Talk to a plumber about this
One call reaches a plumbing company taking calls in your ZIP.
Your Water Matters
Very soft, acidic or highly chlorinated water can wear copper from the inside, causing pinhole leaks. If you have had them, see pinhole leak in copper pipe.
What a Repipe Costs
HomeAdvisor puts a whole-house repipe at about $4.50 per square foot of house, with labor about 70% of the total; PEX usually brings the material share down. See repipe house cost and repiping.
The Call
Call for quotes in both materials before deciding. (888) 217-6781 connects you to a plumbing company taking calls in your ZIP. Follow the short menu, enter your 5-digit ZIP and stay on while it connects; if it does not connect, call once more, because the companies taking calls change minute to minute.
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Frequently Asked Questions
Is PEX better than copper?
Neither is better everywhere. PEX costs less, installs faster and resists freezing better. Copper is long proven, heat and UV tolerant, and preferred for exposed runs.
How long does PEX last compared to copper?
Copper systems commonly last 50 years or more. PEX has been in wide US use since the 1990s; manufacturers rate it for decades when kept from sunlight and installed to spec.
Does PEX burst when it freezes?
PEX expands and resists splitting better than copper, but it can still burst, and its fittings can fail. Insulating and heating the space still matter.
Sources
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Disclaimer: HearthDry is an independent educational resource. This article is for informational purposes only and does not constitute professional, legal, or insurance advice. Consult licensed professionals before making decisions about your property or insurance claims.
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