PEX Installation Methods
Updated February 20, 2026
PEX has completely changed residential plumbing. It's flexible, freeze-resistant, doesn't corrode, and you don't need a torch to install it. The learning curve is way shorter than copper. The main decision is which connection method to use -- crimp, clamp, or expansion -- and that comes down to your budget, the tools you have, and what your local code allows.
Overview
PEX has completely changed residential plumbing. It's flexible, freeze-resistant, doesn't corrode, and you don't need a torch to install it. The learning curve is way shorter than copper. The main decision is which connection method to use -- crimp, clamp, or expansion -- and that comes down to your budget, the tools you have, and what your local code allows.
What to Know
Tools & Materials
- PEX pipe (A, B, or C -- check local code)
- Appropriate fittings for your connection method
- Crimp tool, cinch tool, or expansion tool
- PEX cutter (clean, square cuts matter)
- Go/no-go gauge (for crimp connections)
- Pipe support clamps and hangers
Step by Step
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Plan your layout
Map out the pipe runs from the water source to each fixture. PEX can run in a home-run configuration (individual lines from a manifold to each fixture) or trunk-and-branch (like traditional copper). Home-run costs more in pipe but gives better pressure and easier shutoff control.
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Cut the PEX
Use a PEX cutter for clean, square cuts. A crooked cut means the fitting won't seat properly. Don't use a hacksaw -- it leaves burrs that can compromise the seal.
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Make the connection
For crimp: slide ring over pipe, insert fitting, position ring 1/8 to 1/4 inch from the end, crimp. For clamp: slide clamp over pipe, insert fitting, position clamp, squeeze the ear with the cinch tool. For expansion: slide ring over pipe, expand the pipe and ring, insert fitting, wait 30 seconds for the pipe to shrink back.
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Check every connection
For crimp connections, use a go/no-go gauge on every ring. If it fails the gauge, cut it off and redo it. There's no fixing a bad crimp. Pressure test the system before closing walls -- 80 PSI for 30 minutes with no drop.
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Support the pipe properly
PEX needs support every 32 inches on horizontal runs and every 4-6 feet on vertical runs. Use proper PEX hangers -- not metal straps that can chafe through the pipe. Keep PEX away from hot exhaust vents and direct sunlight (UV degrades it).
Pro Tips
- Always use the go/no-go gauge on crimp connections. A connection that looks fine but fails the gauge will leak eventually.
- Color-code your PEX: red for hot, blue for cold. It's not required but saves confusion for the next person who works on it.
- Leave a service loop (extra coiled PEX) at fixture connections so there's slack for future repairs.
- PEX expands and contracts with temperature. Don't pull it tight -- leave some slack in every run.
Mistakes to Avoid
- Using brass fittings designed for copper with PEX. PEX requires fittings specifically designed for PEX connections.
- Running PEX in direct sunlight -- UV breaks it down. Cover any exterior-exposed sections.
- Not supporting the pipe properly, which causes sagging and stress on connections.
- Overtightening crimp connections doesn't make them better -- it deforms the ring and causes failure.
When to Call a Pro
If you're doing a whole-house repipe, it's worth considering a pro -- they'll have the right tools and can pull permits. For individual fixture connections or small repairs, PEX is one of the most DIY-friendly plumbing materials out there.
Bottom Line
PEX is easier and faster than copper for most residential plumbing work. Pick a connection method that fits your budget and project scope, cut square, and check every connection with the appropriate gauge. It's forgiving material that makes plumbing accessible to anyone with basic tool skills.