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Now it's time to run the new PEX lines. Use blue PEX for cold water and red PEX for hot water to maintain clear identification. Starting at the manifold, unroll and run a continuous PEX line to each fixture location. You can often follow the same paths as the old pipes. If you need to drill new holes through studs or joists, use an auger or spade bit and keep the holes centered to avoid accidental piercing with future nails or screws. To prevent sagging and water hammer noise, secure the PEX tubing with plastic pipe hangers every 32 inches on horizontal runs and every 48 inches on vertical runs. PEX is flexible, so use wide, sweeping turns instead of sharp 90-degree fittings where possible.

You're viewing a step from: How to Replace Grey Polybutylene Pipe with PEX

Intermediate

40 hours

2/4 Inventory

This is a comprehensive, step-by-step guide for a whole-house repipe project, detailing the process of removing problematic grey polybutylene (PB) plumbing and replacing it with a modern, reliable PEX (cross-linked polyethylene) system. The instructions assume the use of a central PEX manifold and the crimp/clamp connection method, which is common for DIY and professional installations.

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Frequently Asked Questions

Given the 40-hour estimate, is a whole-house PEX repipe truly an 'intermediate' DIY project, or should I hire a professional?

While labeled intermediate, this project demands significant time, precision, and adherence to plumbing codes. It's suitable for experienced DIYers comfortable with tools and problem-solving, but if you're unsure about the complexity or time commitment, consulting a licensed plumber is advisable, especially for main supply connections and final inspections.

What are the most crucial safety precautions I must take when replacing polybutylene pipes with PEX?

Always shut off and thoroughly drain the main water supply before starting. Wear appropriate PPE, including eye protection, and ensure good ventilation if soldering is required for main tie-ins. Be cautious when cutting into existing lines to prevent accidental damage or uncontrolled water release, and always have a plan for containing potential leaks.

The project lists specific PEX tools like crimp tools and cutters. Are these absolutely essential, or are there budget-friendly alternatives?

Yes, specialized PEX tools such as a PEX pipe cutter and a crimp/clamp tool are essential for making reliable, leak-free connections. While there are different brands and price points, investing in quality PEX-specific tools is crucial for successful installation. Avoid using standard tools for PEX connections, as they can lead to costly leaks and system failures.

What are common mistakes DIYers make during PEX installation, particularly with crimp connections, and how can they be avoided?

Common mistakes include improper crimp ring placement, not fully deburring cut pipes, and over-tightening manifold connections. Always ensure the crimp ring is correctly positioned over the fitting's barb, deburr all pipe ends to prevent leaks, and follow manufacturer guidelines for manifold valve torque. Testing sections of the system as you go can help catch issues early.