Can You Mix PEX And Copper Pipes?

When working on your home, you may find that you have copper plumbing. Copper pipes have been reliably used throughout homes for a very long time now. But when it comes to replacing or adding to your copper plumbing, you may want a less expensive, easier to work with, alternative. If you've been exploring your options, maybe you wonder if you can use PEX to connect to your copper pipes. We have done the research and have the answer for you.

PEX works well with existing copper plumbing. There is no concern that any of the materials used in either type of pipe will negatively react to the other type of pipe, making them very compatible. The two types of pipe easily connect together using several different types of connectors, such as:

  • Solder-on
  • Push-to-connect
  • Screw-on

PEX is easy to work with for DIYers and is often more affordable than copper. This makes it a good option when you need to replace part of your existing pipes. There are well-tested, reliable ways to join the two. We discuss the steps to join the two kinds of pipes in detail below.

A series of PEX pipes running through the ceiling of a house next to plumbing lines, Can You Mix PEX And Copper Pipes?

Connecting PEX To Copper

Your current pipes might be copper, but maybe you want to use PEX on your repairs or additions. How do you do that?

Luckily, there are several options available for this. Each type of connector requires its own process and tools for installation, but none of the steps are especially difficult.

Solder-On Connectors

These connectors solder onto the copper pipe, then you connect the other end to a PEX pipe using the crimp on or cinch PEX connection. You need the following tools:

A Torch

Click here to see this torch on Amazon.

A Lead-Free Solder

Click here to see this solder on Amazon.

To complete this project, you'll also need the following tools:

  • A Tubing Cutter
  • A Pipe Cleaning Brush
  • Solder Flux
  • A Crimping Tool Or A Cinch Tool
  • PEX Cutting Tool

On top of the tools, you will also need the appropriate adapters, such as this one:

PEX Adapter

Click here to see this adapter on Amazon.

And you need the crimp or cinch rings for the PEX, like these:

PEX Crimp Ring

Click here to see this crimp ring on Amazon.

Sharkbite PEX Cinch Ring

Click here to see this cinch ring on Amazon.

To connect the brass pipe to the connector, follow these steps:

  1. Cut the copper pipe with the tubing cutter.
  2. Use a pipe cleaning tool to clean the outside of the pipe and the inside of the connector.
  3. Apply flux to the outside of the pipe and the inside of the connector.
  4. Slide the connector into place over the pipe.
  5. Heat the joint with a torch.
  6. Apply solder to the seam, letting it melt and draw in between the pipe and connector.

That takes care of the connection on the copper pipe. Now we need to connect to the PEX.

To connect the PEX onto the connector, follow these steps:

  1. Trim the PEX with the cutting tool, being careful to get a clean, square cut.
  2. Slide a crimp ring or cinch ring onto the PEX.
  3. Push the PEX onto the connector.
  4. Slide the crimp ring or cinch ring up to about 1/8 inch from the end of the PEX and crimp or cinch, depending on which type you chose.

You can see the process in this video:

Push-To-Connect Connectors

These connectors don't require soldering, which makes them much easier to install. Some people have concerns about how well they seal and how durable they are, but they have a good track record and have been tested and approved for use in underground and behind-wall applications under the plumbing codes. They are much more expensive than the other types of connectors, though.

With this kind of connector, you don't need the soldering supplies, but you still need these tools:

  • Tubing cutter
  • Pipe cleaning brush
  • PEX cutter

Additionally, you need a special connector, like this one:

Push-To-Connect Straight Coupler

Click here to see this connector on Amazon.

The process for installing this is much simpler than the solder-on connectors. Here is how you do it:

  1. Cut the copper pipe with a tubing cutter.
  2. Use the pipe cleaning tool to clean the outside of the pipe.
  3. Slide the connector all the way onto the copper pipe.
  4. Trim the PEX with the PEX cutter.
  5. Push the PEX all the way onto the connector.

That's it. It is very simple, and much quicker than connecting with the solder-on version.

You can see the process here:

Screw-On Connectors

Screw-on connectors are almost a subset of the previous connector types. If you have an existing threaded connection on a copper pipe, you can hook to it by installing a threaded connector on the PEX, like this one:


Click here to see this fitting on Amazon.

You could connect that to the PEX using the same crimp or cinch connectors and tools mentioned above.

You could also solder a threaded connector onto the copper pipe if one does not already exist. You would do that using the exact same process outlined above. For that, you would need a connector similar to this one:

Male Adapter Fitting

Click here to see this fitting on Amazon.

There are also push-to-connect versions of these same types of adapters, which will usually work on either the PEX or the copper pipes.

Male NPT Threaded Connector

Click here to see this connector on Amazon.

Female NPT Threaded Connector

Click here to see this connector on Amazon.

With these connectors, you would install one on either the PEX or copper pipe and connect to the appropriate existing threaded connector on the other type of pipe.

As you can see, connecting copper to PEX is not difficult. There are options to fit your skill level and budget, whatever it may be. It is a simple DIY project and will provide reliable connections for many years to come.

Is Sharkbite And PEX The Same Thing?

PEX and Sharkbite are not the same thing. PEX is cross-linked polyethylene tubing, a flexible pipe made for use in plumbing. Sharkbite is a brand of connectors used in plumbing, specifically the push-to-connect type. These are sometimes used on PEX pipe, but they are not the same thing.

Will PEX Last As Long As Copper?

Nobody knows for certain if PEX will last as long as copper. There are many factors that can play into it.

Under some circumstances, copper can corrode quickly. This includes things like the wrong pH level in the water or even acidic solder used during installation.

On the other hand, copper pipes often last far in excess of 50 years, as proven in many installations even decades older than that. Currently, most PEX pipes come with a 25-year warranty, while copper often comes with a 50-year warranty.

In Europe, there are many buildings using PEX that show no problems more than 30 years after installation. And PEX has an advantage when it comes to frozen pipes, since it will expand somewhat and the copper can burst.

In the end, both are incredibly durable and well-tested plumbing systems. You really can't go wrong with either one.

If you want to know more about copper pipes, be sure to check out How Long Do Copper Pipes Last And When To Replace Them?

Should You Replace Copper With PEX?

If you are replacing your current pipes anyway, PEX is a viable alternative. Most people consider it easier to install, and it is usually much cheaper than copper.

PEX comes in long rolls, meaning you can run a pipe across an entire home without any joints, provided you can make curves through the walls. With copper, you'd have to piece it together and have joints everywhere there is a change of direction.

When it comes down to it, they are both solid choices. Which you go with is up to you, but many consider PEX better for a DIY project because of its ease of installation.

In Closing

You should encounter no problems when using copper and PEX together. There are simple methods to connect the two, either with a push-to-connect system or a solder-on connector on the copper side, and push-to-connect or crimp-on for the PEX pipe. If PEX sounds like a good choice for your project, the existence of copper is not a roadblock, so you can feel free to use them together.

Before you go, be sure to check out these other PEX-related articles:

Is Pex Plumbing Easy To Install?

Can PEX Pipes Freeze And Burst? What Homeowners Need To Know

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