The Ultimate Guide to PEX Pipe Installation

If you are planning any PEX pipe installation project, then this guide is for you. It will help you choose the right PEX pipe, take you through the process, and recommend accessories you may need for the installation process.

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What is a PEX Pipe?

PEX refers to cross-linked polyethylene, a flexible plastic tubing used for plumbing and heating systems in residential and commercial construction. The popularity of PEX pipe is down to its outstanding longevity owing to its impressive corrosion and freezing resistance and flexibility.

PEX Pipe Dimensions
PEX Pipe Dimensions

Step 1: Know the Type of PEX Pipe to Install

When evaluating PEX pipes for your project, you need to consider three primary varieties.

They include:

  • PEX-A: It is manufactured via the Engel method of cross-linking the polyethylene molecules. It finds use in plumbing and radiant floor heating systems as well as residential and commercial.
  • PEX-B: Utilizes the Silane manufacturing method of cross-linking polyethylene molecules. Commonly used in residential plumbing and heating systems and also in composite pipes with aluminum.
  • PEX-C: This particular PEX pipe is developed from polyethylene molecules that are cross-linked by subjecting them to electronic irradiation.

Step 2: Choose Suitable PEX Pipe Sizes

PEX Piping Sizes
PEX Piping Sizes

Depending on your plumbing needs, you can choose any of these PEX pipe sizes:

  • ½ Inch: Finds one of the most common uses, especially in residential plumbing. It is suitable for a wide range of applications such as hot and cold water supply lines, and appliance and fixtures connections.
  • ¾ Inch: Finds use in large plumbing projects and for main water lines. It is suitable for applications with high flow rates and increased water volume.
  • 1 Inch: Mostly utilized for applications with high water flow requirements such as industrial projects or large commercial plumbing systems.

Step 3: Assemble the PEX Pipe Installation Tools and Accessories

PEX Pipe Fittings
PEX Pipe Fittings

When installing PEX pipes, you need tools and accessories. You will use the tools to transform PEX pipes into suitable forms ready for installation.

Tools such as the crimping tool and pipe cutter alongside several fittings are necessary for PEX pipe installation.

Common PEX pipe accessories include:

PEX Pipe AccessoryFunction
Manifolds· This is essentially a larger PEX pipe that connects to several other smaller pipes working as a distribution terminal. Many pipe designs for plumbing systems run from the manifold which is usually the entry point for the main water line.
Coupler· This device extends the pipe’s length by joining two sections of PEX pipes. Are also available in various sizes and commonly used in plumbing installations to connect two PEX sections.
End Plug· It closes off a line or blocks a PEX pipe end. As such, where an end plug is used, continuous flow is not desired.
90-Degree Elbow· Useful in changing the direction of a PEX pipe by 90 degrees especially when navigating around corners or obstacles.
Reducer· A reducer allows you to affix PEX pipes of different diameters. These fixtures come in different sizes and end styles.


· Allows the PEX pipe to branch off in a perpendicular direction, forming a T-shaped connection. Are ideal for creating distribution points like supplying water to multiple fixtures from a single source
Crimp Rings· These fixtures are fasteners typically used on crimp fittings used with PEX pipes. Mostly fashioned from copper, crimp rings are differentiated by their diameters.


Step 4: Design and Cut PEX Pipes Ready for Installation


First lay out the design for your PEX plumbing system, highlighting the location of fixtures, connections, and shut-off valves. Accommodating a PEX manifold will ensure a more organized distribution.

Using your design layout, cut the PEX pipe according to the required measurements using a pipe cutter. Ensure the cuts are clean and straight to ensure a proper seal. You can deburr or smoothen the ends using sandpaper or other deburring tool.

Step 5: Install Necessary PEX Pipe Fittings and Connect PEX Piping

Installed PEX Pipe
Installed PEX Pipe

Slide the appropriate PEX fittings onto the cut ends ensuring they are fully inserted and correctly seated. Thereafter, use a PEX crimping tool to secure the fittings in place ensuring a watertight connection.

You can use PEX pipe supports like straps or hangers to secure the PEX pipes in place. These should be positioned at regular intervals and at connection points to prevent stress on or sagging of the pipes.

Crimp connections are commonly used to secure PEX pipes to fittings and ensure a watertight seal. In making a PEX crimp connection:

  • Cut the PEX Pipe in accordance with the design measurements, ensuring the cut is straight, clean, and square.
  • Slide the Crimp Ring onto the pipe end providing some allowance for the fitting.
  • Insert the Fitting to the PEX pipe end ensuring it is fully seated with no gap.
  • Position the Crimp Ring such that it is between an eighth and a quarter an inch away from the end of the pipe.
  • Crimp the Connection by positioning the jaws of the crimping tool over the crimp ring squeezing with a firm and steady motion.

Step 6: Label and Insulate PEX Pipes for Installation

Label the PEX pipes indicating where each pipe goes and what it supplies. Using color coordination is also ideal i.e. red for hot water and blue for cold. This is helpful for future maintenance and repairs.

You can insulate PEX pipes in cold regions or outdoor installations to protect them from freezing temperatures.

Step 7: Test Connection Before Finishing PEX Piping Installation

Ultimately, before sealing in the PEX pipes, perform a pressure test. Turn the water supply back on and identify any leaks. Upon ensuring everything is functioning as expected seal the PEX pipes.Top of Form


PEX pipe installations are commonly employed for plumbing and radiant floor heating systems. Proper installation techniques and compatible fittings are necessary to ensure long-term performance. It is also essential to adhere to local building codes and manufacturer guidelines when using PEX pipes.

More Resources:

Learn how to Conduct PEX Pipe Repair – Source: D&R

What is PEX Pipe – Source: D&R

PEX A VS PEX B – Source: D&R

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