Diy plumber’s secret: how to join pex pipe underground like a pro (step-by-step guide)

When it comes to plumbing underground, PEX pipe has emerged as a popular choice due to its flexibility, durability, and ease of installation. However, joining PEX pipe underground requires a slightly different approach than above-ground installations. This blog post will provide a comprehensive guide on how to join PEX pipe underground, ensuring a secure and leak-free connection.

Understanding PEX Pipe

PEX (Polyethylene Cross-linked) is a type of plastic pipe that is made from high-density polyethylene. It is lightweight, flexible, and resistant to corrosion and freezing temperatures. PEX pipe is available in various sizes and thicknesses, making it suitable for a wide range of plumbing applications.

Tools and Materials

Before you start joining PEX pipe underground, you will need the following tools and materials:

• PEX pipe
• PEX pipe cutter
• PEX expansion tool
• PEX crimp rings or clamps
• Crimping tool
• Shovel
• Trenching tool
• Backfill material (e.g., sand, gravel)

Step-by-Step Guide to Joining PEX Pipe Underground

1. Dig the Trench

Dig a trench that is deep enough to accommodate the PEX pipe and allow for proper drainage. The trench should be wide enough to provide ample working space.

2. Prepare the Pipe Ends

Cut the PEX pipe to the desired length using a PEX pipe cutter. Ensure that the cuts are clean and perpendicular to the pipe. Use a PEX expansion tool to expand the ends of the pipe, creating a bell-shaped opening.

3. Insert the Pipe Fittings

Insert the PEX pipe fittings, such as couplings or elbows, into the expanded ends of the pipe. Make sure that the fittings are fully inserted and seated properly.

4. Crimp the Rings or Clamps

Use a crimping tool to crimp the PEX crimp rings or clamps onto the fittings. The crimp should be tight enough to create a secure connection but not so tight that it damages the pipe.

5. Backfill the Trench

Once the PEX pipe is joined, backfill the trench with the excavated material, such as sand or gravel. Compact the backfill material to ensure stability.

Tips for Success

• Use a PEX pipe cutter specifically designed for PEX pipe.
• Expand the PEX pipe ends evenly and to the correct depth.
• Crimp the rings or clamps securely but without overtightening.
• Backfill the trench gradually and compact the material thoroughly.
• Test the connections for leaks before burying the pipe completely.

Troubleshooting Common Issues

• Leaking connections: Ensure that the PEX pipe ends are properly expanded and the crimp rings or clamps are tight.
• Difficulty expanding the pipe: Check if the PEX expansion tool is compatible with the pipe size and type.
• Pipe damage: Avoid overtightening the crimp rings or clamps, as this can damage the pipe.

Wrapping Up: A Secure and Durable Underground Connection

By following the steps outlined in this guide, you can effectively join PEX pipe underground and create a secure and durable connection. Remember to use the appropriate tools, materials, and techniques to ensure a leak-free and reliable plumbing system.

Frequently Asked Questions

1. Can I use PEX pipe for all underground plumbing applications?
Yes, PEX pipe is suitable for a variety of underground plumbing applications, including water supply, drainage, and radiant heating.

2. How deep should I bury PEX pipe underground?
The depth of the trench will depend on the local climate and soil conditions. In most cases, a depth of 12-18 inches is sufficient.

3. Is it necessary to use a trenching tool?
A trenching tool can make digging the trench easier and more efficient, especially in hard or rocky soil.

4. How do I test the connections for leaks?
Pressurize the pipe system and check for any leaks at the connections. You can use a soapy water solution to identify leaks more easily.

5. Can I use other types of pipe fittings with PEX pipe?
Yes, you can use brass or copper fittings with PEX pipe by using PEX adapters. However, it is recommended to use PEX fittings for optimal performance.