How to Re-Plumb Your House with PEX: A Step-by-Step Guide

If your home still uses old galvanized steel or corroded copper pipes, you’ve probably dealt with low water pressure, discolored water, or even unexpected leaks. How to re-plumb your house with PEX is a smart, future-proof solution that thousands of U.S. homeowners are choosing for its durability, flexibility, and ease of installation. Whether you’re renovaging an older property or upgrading your plumbing system, this guide walks you through the entire process with clarity and confidence—even if you’ve never held a pipe cutter before.

Why Choose PEX for Repiping Your Home?

Before diving into the steps, it’s essential to understand why PEX (cross-linked polyethylene) has become the go-to material for modern plumbing.

Unlike rigid copper or PVC, PEX is flexible, freeze-resistant, and less prone to leaks due to fewer required connections. According to the U.S. Department of Energy, homes repiped with PEX experience up to 40% fewer plumbing failures over a 10-year period compared to traditional materials.

The International Association of Certified Home Inspectors (InterNACHI) notes that PEX installations typically cost 30–50% less than copper, thanks to lower material costs and faster installation times.

💡 Pro Tip: PEX isn’t approved for outdoor or UV-exposed use, so it’s strictly an indoor solution—perfect for whole-house repiping.

What Tools and Materials Do You Need?

Re-plumbing with PEX is DIY-friendly, but only if you have the right gear. Here’s your checklist:

Materials:

• PEX tubing (A, B, or C type—Type A is most flexible; Type B is most common)
• PEX crimp rings or expansion sleeves (depending on your connection method)
• Shut-off valves, manifolds (optional but recommended)
• Pipe insulation (for cold climates)

Tools:

• PEX tubing cutter
• Crimping tool or expansion tool
• Deburring tool
• Tape measure
• Pipe supports/clamps
• SharkBite or similar push-fit fittings (for hybrid setups)

🔗 For more on PEX types and standards, see the Wikipedia entry on PEX.

Step-by-Step: How to Re-Plumb Your House with PEX

Step 1: Turn Off Water & Drain the System

• Shut off the main water supply.
• Open all faucets (starting from the highest point) to drain residual water.
• Use an air compressor (optional) to blow out remaining water from pipes for a dry workspace.

Step 2: Remove Old Plumbing

• Carefully remove old pipes (copper, galvanized, etc.).
• Cap or seal any remaining sections not being replaced.
• Clean the work area—remove nails, brackets, or debris.

Step 3: Plan Your PEX Layout

• Decide between a home-run (manifold) system or branch system.
  • Home-run: One line per fixture from a central manifold. Offers consistent pressure and easier leak isolation.
  • Branch: Traditional tree-like layout. Uses less tubing but may reduce pressure with multiple fixtures running.
• Measure distances: Add 10% extra for bends and mistakes.

Step 4: Install the Manifold (If Using)

• Mount the manifold near the main water line (often in the basement or utility room).
• Connect hot and cold inlets to your water heater and main supply using PEX or copper adapters.
• Label each outlet (e.g., “Master Bath Hot,” “Kitchen Cold”).

Step 5: Run PEX Tubing to Fixtures

• Use ½-inch PEX for most residential fixtures (¾-inch for main lines).
• Secure tubing every 32 inches horizontally and 6 feet vertically with plastic clamps.
• Avoid sharp bends—maintain a bend radius of at least 6 inches for ½-inch PEX.
• Never kink the tube; use PEX bend supports if needed.

Step 6: Make Connections

• Crimp method: Slide ring onto tube, insert fitting, then crimp with tool. Verify with go/no-go gauge.
• Expansion method: Use an expansion tool to widen the tube, insert fitting, and let it contract.
• Push-fit (e.g., SharkBite): No tools needed—just push in. Great for repairs or tight spaces.

⚠️ Note: Local codes vary. Always check with your municipality—some require permits or licensed plumbers for full repiping.

Step 7: Pressure Test the System

• Cap all open ends.
• Turn water back on slowly.
• Check for leaks at every connection.
• For a formal test: Use a pressure gauge; system should hold 80 PSI for 2+ hours with no drop.

Step 8: Insulate & Finalize

• Wrap PEX in foam insulation in unheated areas to prevent freezing.
• Close walls only after 24 hours of leak-free operation.
• Update your home’s plumbing diagram for future reference.

PEX vs. Copper vs. CPVC: Which Is Best?

Source: Plumbing-Engineer.com & HomeAdvisor Cost Data 2024

Common Mistakes to Avoid

• Using barbed fittings without clamps → Leads to leaks under pressure.
• Running PEX through sharp metal studs → Always use grommets or protective sleeves.
• Ignoring local codes → Some states (e.g., California) restrict certain PEX types.
• Skipping insulation in cold zones → Even PEX can freeze and stop water flow (though it rarely bursts).

FAQ Section

Q1: Can I re-plumb my house with PEX myself?

Yes—if you’re comfortable with basic tools and follow code requirements. However, full-house repiping often requires a permit, and some jurisdictions mandate a licensed plumber for final inspections.

Q2: How much does it cost to re-plumb a house with PEX?

For a 2,000 sq ft home, DIY materials cost $1,500–$3,000. Hiring a pro typically runs $4,000–$10,000, depending on layout and accessibility.

Q3: Is PEX safe for drinking water?

Yes. PEX is certified by NSF International (Standard 61) for potable water. Choose brands labeled “NSF-pw” to ensure safety.

Q4: How long does PEX last?

Studies by the Plastics Pipe Institute show PEX lasts at least 50 years under normal conditions—longer than most homeowners stay in one house.

Q5: Can PEX be used for both hot and cold water?

Absolutely. PEX handles temperatures from -40°F to 200°F, making it ideal for all indoor plumbing lines.

Q6: Do I need a manifold system?

Not required, but highly recommended. A manifold reduces pressure drops, simplifies troubleshooting, and allows individual fixture shut-offs—great for vacations or repairs.

Conclusion

Re-plumbing your house with PEX isn’t just a repair—it’s an investment in comfort, efficiency, and home value. With lower costs, faster installation, and superior performance in freezing conditions, PEX stands out as the modern standard for residential plumbing.

If you’ve found this guide helpful, share it with a friend who’s tackling a home upgrade—or pin it for your next project! Got questions? Drop them in the comments below. Happy plumbing! 💧🔧