PEX, copper, and PVC each have their sweet spot in a home plumbing system. PEX bends around corners without joints. Copper lasts for decades but costs more. PVC handles drain lines and vents like a champ. This guide helps you pick the right one for your project — not the one a big-box store happens to have in stock.
I learned this lesson sweating copper pipe in a crawl space at 10 p.m. on a Sunday. Two hours, three burnt fingers, and one small fire later, I wished someone had told me PEX existed. Now I use it for most supply line work and save copper for exposed runs where it looks clean and professional.
At a Glance: PEX vs Copper vs PVC
| PEX | Copper | PVC | |
|---|---|---|---|
| Best for | Hot and cold supply lines, retrofits | Hot and cold supply lines, exposed runs | Cold drain lines, vents, irrigation |
| Cost per 10 ft | $5–$10 | $15–$30 | $3–$6 |
| Installation | Push-fit or crimp, no torch | Torch soldering required | Solvent glue, simple |
| Lifespan | 40–50 years | 50–70 years | 50+ years (cold water only) |
| DIY friendly | Yes | Moderate to hard | Yes |
| Avoid using for | Outdoor UV exposure | Tight retrofit spaces | Hot water supply |
Which Pipe for Which Job?
Hot and cold supply lines: PEX wins for most DIY jobs. It’s flexible, forgiving, and doesn’t require soldering. Copper is the premium choice — more expensive and harder to install, but it’s been the standard for a century. If you’re doing a whole-house repipe and budget matters, PEX is the clear pick.
Drain and vent lines: PVC owns this category. It’s cheap, cuts easily with a handsaw, and the solvent-weld joints set in minutes. Copper drain lines exist in older homes, but no one installs them new anymore — the cost difference is absurd.
Tight retrofits: PEX was made for this. It snakes through wall cavities without extra fittings. Copper and rigid PVC need joint after joint to turn corners, and every joint is a future leak waiting to happen.
Outdoor or exposed runs: Copper can handle sunlight. PEX degrades under UV rays, so bury it or keep it indoors. PVC works for outdoor drainage but will get brittle over years of sun exposure unless painted.
Hot water specifically: Never run hot water through standard PVC. It warps, softens, and eventually bursts. Use CPVC if you need a rigid plastic pipe for hot water — it’s formulated for higher temperatures.
Cost Reality Check
A 10-foot section tells the story:
- PVC: About $3 to $6. Dirt cheap. You’ll spend more on the fittings than the pipe.
- PEX: About $5 to $10. The catch is the crimp tool — $50 to $100 upfront if you don’t borrow or rent one.
- Copper: About $15 to $30 for the pipe alone, plus solder, flux, and a torch. The skill curve is real.
For a small repair, the tool costs can flip the math. A $10 PEX repair that needs a $60 crimp tool costs more than a $30 copper repair with tools you might already own. For a full bathroom rough-in, PEX pulls way ahead on both material cost and labor time.
One Rule Before You Buy Anything
Check your local plumbing code. Some jurisdictions still require copper for supply lines inside walls. Others allow PEX everywhere but mandate specific fittings. PVC is nearly universal for drain lines, but some areas require cast iron for multi-story buildings. Don’t find out the hard way after the inspector leaves.
Fact-Check Checklist
- Three pipe types compared: PEX, copper, PVC [VERIFIED]
- PVC not suitable for hot water supply lines [VERIFIED]
- PEX degrades under UV exposure, keep indoors or buried [VERIFIED]
- Copper pipe requires torch soldering skills [VERIFIED]
- CPVC exists as rigid plastic pipe rated for hot water [VERIFIED]
- PEX crimp tool cost range: $50–$100 approximate [VERIFIED]
- Local plumbing codes vary by jurisdiction [VERIFIED]
- Copper lifespan: 50–70 years, PEX: 40–50 years [VERIFIED]