PEX Stub-Out Secrets: Avoid Leaks & Future Headaches!

PEX Stub-Out Secrets: Avoid Leaks & Future Headaches!

"Stubbing out pex," the process of creating a short PEX pipe extension from a wall or floor to connect to a fixture, can seem simple. However, improper execution can lead to leaks, reduced water pressure, and costly repairs down the line. This guide provides essential knowledge for successfully stubbing out PEX, preventing common problems, and ensuring a long-lasting, leak-free connection.

Understanding the Importance of Proper Stub-Out Technique

A PEX stub-out serves as the final connection point between your plumbing system and fixtures like faucets, toilets, and showerheads. Its accessibility makes it vital for maintenance and future fixture replacements. A poorly executed stub-out can cause several issues:

• Leaks: Leaks lead to water damage, mold growth, and increased water bills.
• Reduced Water Pressure: Kinks or sharp bends in the PEX can restrict water flow.
• Difficulty Connecting Fixtures: Improper length or positioning can make connecting fixtures awkward or impossible.
• Future Repairs: Difficult repairs due to inaccessible or improperly installed stub-outs are a common problem.

Essential Materials and Tools for Stubbing Out PEX

Having the right materials and tools readily available ensures a smoother, more professional installation.

• PEX Tubing: Choose the correct size PEX for your application (typically 1/2" or 3/4").
• PEX Fittings:
  • Elbows (90-degree): For turning the PEX at the wall or floor.
  • Stub-Out Elbows: Specialized elbows designed for secure mounting.
  • Couplings: For connecting PEX segments.
• Mounting Brackets or Stub-Out Clamps: Securely anchors the stub-out to the framing.
• PEX Cutter: For clean, square cuts on the PEX tubing.
• PEX Crimp or Expansion Tool: Dependent on the chosen connection method (see below).
• Crimp Rings or Expansion Rings: Corresponding to the PEX size and connection type.
• Measuring Tape: For accurate length measurements.
• Marker or Pen: For marking cutting points.
• Drill and Screws: For attaching mounting brackets to framing.
• Safety Glasses: Protect your eyes from debris.
• Gloves: Protect your hands.

Choosing the Right Connection Method: Crimp vs. Expansion

There are two primary methods for creating PEX connections: crimp and expansion. Each has its advantages and disadvantages.

• Crimp Connections:
  • Process: A copper or stainless steel ring is placed over the PEX tubing, and a crimp tool compresses the ring, creating a tight seal around the fitting.
  • Pros: Relatively inexpensive tools and materials. Widely available.
  • Cons: Can’t be reused. Requires specific crimp tool calibration.
• Expansion Connections:
  • Process: A special tool expands the PEX tubing before inserting it onto the fitting. As the PEX returns to its original size, it creates a tight seal.
  • Pros: Stronger connection compared to crimp. Full-flow connection (less restriction).
  • Cons: More expensive tools. Requires more space for the expansion tool.

Consider these factors when choosing your connection method.

Step-by-Step Guide to Stubbing Out PEX

Following these steps will help you create a secure and professional stub-out.

1. Planning and Measurement:

   • Determine the desired location and height of the stub-out.
   • Measure the distance from the water supply line to the stub-out location.
   • Add extra length to accommodate bends and connections.

2. Cutting the PEX Tubing:

   • Use a PEX cutter to make a clean, square cut on the PEX tubing. A straight cut is essential for a leak-proof seal.

3. Making the Connections:

   • Crimp Connection:
     1. Slide a crimp ring over the PEX tubing.
     2. Insert the PEX tubing onto the fitting until it bottoms out.
     3. Position the crimp ring according to the fitting manufacturer’s instructions.
     4. Use a PEX crimp tool to crimp the ring. Ensure the tool is properly calibrated.
   • Expansion Connection:
     1. Slide an expansion ring over the PEX tubing.
     2. Use a PEX expansion tool to expand the PEX tubing.
     3. Immediately insert the fitting into the expanded PEX tubing.
     4. Hold the fitting in place until the PEX contracts and creates a tight seal.

4. Securing the Stub-Out:

   • Use a stub-out elbow or a regular elbow in conjunction with a mounting bracket or clamp.
   • Position the elbow at the desired height and orientation.
   • Secure the bracket to the wall or floor framing using screws. Ensure the bracket is firmly attached to prevent movement.

5. Pressure Testing:

   • Before closing up the wall or floor, pressure test the connection to check for leaks.
   • Turn on the water supply and inspect all connections for any signs of leaks.
   • If leaks are found, repair the connection immediately.

Troubleshooting Common PEX Stub-Out Problems

• Leaks at Connections:
  • Crimp: Ensure the crimp ring is properly positioned and crimped. Recrimp if necessary.
  • Expansion: Ensure the PEX was fully expanded and the fitting was inserted immediately.
  • If problems persist, cut the PEX and try again with new fittings and rings.
• Kinks in PEX:
  • Avoid sharp bends. Use elbows to make turns.
  • If a kink occurs, it is best to replace the section of PEX.
• Incorrect Stub-Out Length:
  • Carefully measure and plan the length of the stub-out before cutting the PEX.
  • If the stub-out is too short, use a coupling to extend it.
  • If the stub-out is too long, cut it shorter.

Best Practices for Long-Lasting Stub-Outs

• Use Quality Fittings: Invest in reputable brands of PEX fittings.
• Proper Tool Maintenance: Regularly check and maintain your PEX crimp or expansion tool.
• Secure Mounting: Ensure the stub-out is securely mounted to the framing.
• Insulate PEX: In cold climates, insulate the PEX to prevent freezing.
• Avoid Sharp Bends: Use elbows to create gradual turns in the PEX.
• Follow Manufacturer’s Instructions: Always follow the manufacturer’s instructions for the specific PEX system you are using.

And that’s a wrap on stubbing out PEX the right way! Hopefully, these tips help you avoid some headaches down the line. Happy plumbing!