Install Pex Pipe Under Sink in 15 Minutes: The Ultimate Step-by-Step Guide

PEX pipes have become increasingly popular in plumbing applications due to their flexibility, durability, and ease of installation. If you’re looking to upgrade or replace the plumbing under your sink, installing PEX pipes is a great option. In this comprehensive guide, we’ll walk you through the step-by-step process of how to install PEX pipe under the sink, ensuring a leak-free and efficient plumbing system.

Tools and Materials

Before you begin, gather the necessary tools and materials:

• PEX pipe
• PEX fittings (elbows, tees, etc.)
• PEX cutter
• PEX expander tool
• PEX crimp rings
• Crimping tool
• Wrench or pliers
• Hacksaw
• Measuring tape
• Pencil or marker
• Safety glasses

Safety Precautions

Always wear safety glasses when working with plumbing tools. Shut off the water supply to your sink before starting the installation. If you’re not comfortable working with plumbing, it’s advisable to seek professional assistance.

Step 1: Measure and Cut the PEX Pipe

Measure the length of the PEX pipe you need to reach from the water supply to the faucet. Cut the pipe to the desired length using a PEX cutter. Make sure the cut is clean and perpendicular to the pipe.

Step 2: Attach the PEX Fittings

Determine the type of PEX fittings you need based on your plumbing configuration. For example, you may need elbows to change the direction of the pipe or tees to branch off to multiple outlets. Insert the PEX pipe into the fitting until it reaches the stop.

Step 3: Expand the PEX Pipe

Using a PEX expander tool, expand the end of the PEX pipe where the fitting will be attached. This creates a larger diameter opening that allows the fitting to slide on easily.

Step 4: Insert the Fitting

Slide the fitting over the expanded end of the PEX pipe. Make sure the fitting is fully inserted and seated properly.

Step 5: Crimp the Ring

Place a PEX crimp ring over the fitting. Use a crimping tool to crimp the ring around the pipe and fitting. Ensure the crimps are tight and evenly spaced.

Step 6: Connect to Water Supply and Faucet

Connect the PEX pipe to the water supply valve and the faucet using additional PEX fittings and crimp rings. Turn on the water supply and check for any leaks.

Step 7: Secure the PEX Pipe

Use zip ties or pipe clamps to secure the PEX pipe to the underside of the sink or cabinet. This prevents the pipe from moving or vibrating.

Troubleshooting Tips

• If you encounter a leak, check the crimps to ensure they are tight and properly spaced.
• If the PEX pipe is not expanding properly, make sure the expander tool is the correct size for the pipe.
• If you have difficulty inserting the fitting into the expanded PEX pipe, try using a lubricant.

Quick Answers to Your FAQs

Q: What is the difference between PEX A, PEX B, and PEX C pipes?
A: PEX A is the most flexible and durable type, PEX B is less flexible but still durable, and PEX C is less flexible and less durable.

Q: How long do PEX pipes last?
A: PEX pipes can last up to 50 years or more with proper installation and maintenance.

Q: Can I use PEX pipes for hot and cold water?
A: Yes, PEX pipes are suitable for both hot and cold water applications.