Can You Connect Pex Pipe To Copper?

Picture a home. It’s not just a place to rest your head at night—it’s a complex network of interconnected systems all working together. From the electrical wiring that powers your lights, to the plumbing that delivers clean water to your tap, each component is a critical part of making sure everything runs smoothly.

But what happens when two different materials need to be connected? That’s the question you’ll need to answer when it comes to connecting PEX pipe to copper.

Connecting two different materials can be a challenge, but with the right technique, you can easily and securely join your PEX and copper pipes. In this article, we’ll discuss the various types of connectors available and how to properly prepare the pipes for a successful connection.

You’ll also learn how to pressure test your connection, as well as troubleshoot any issues that may arise. With the right knowledge, you can make sure all of your home’s systems are connected safely and securely.

Understanding PEX Pipe

In this section, we’ll explore the basics of PEX to help get you familiar with this versatile material!

PEX is a type of strong yet flexible pipe made from cross-linked polyethylene. It is widely used in the plumbing industry for residential and commercial applications and is preferred by many due to its durability and cost-effectiveness.

It can also be used for radiant floor heating systems, hydronic baseboard heating, and more.

When it comes to pipe sizing, PEX comes in both nominal and copper pipe sizes, making installation easier and more cost-effective than copper.

There are also several installation methods for PEX, including clamping, crimping, and expansion. Clamping is the most common and uses stainless-steel clamps and rings to connect the pipe.

Crimping utilizes a specialized tool to press a copper ring onto the pipe and is a more permanent solution.

Expansion, on the other hand, uses a tool to expand the pipe and then a fitting is inserted into the pipe and held in place by a metal ring.

Types of Connectors

To make sure your plumbing is up to snuff, it’s important to know the different types of connectors for a secure fit. While the two most common types of connectors used to connect PEX pipe to copper are soldering techniques and compression fittings, there are other options available. Here’s a brief rundown of the different types of connectors:

  • Crimp Fittings: Crimp fittings are the most common type of connector and they’re relatively simple to install. They’re secured using a crimping tool and a crimp ring.
  • Push Fittings: Push fittings are becoming increasingly popular as they’re very easy to install. All you need to do is insert the pipe into the fitting and it will form a secure connection.
  • Compression Fittings: Compression fittings are another popular option and can be used with both copper and PEX pipes. They consist of a nut, a ferrule, and a sleeve, and the connection is made by tightening the nut onto the pipe.
  • Soldering Techniques: Soldering techniques are the most traditional way to join copper pipes and can be used for both copper and PEX pipes. The process requires soldering flux, a soldering torch, and a heat-resistant material such as heat tape.

Preparing the Copper Pipe

Before connecting the pipes, it’s essential to properly prepare the copper pipe with the right tools and techniques.

Soldering techniques are necessary to join copper pipes together in a secure and watertight seal. A pipe cutter is the recommended tool to use when cutting copper pipe as it provides a clean and efficient cut.

The pipe cutter should be used to cut the copper pipe to the precise length needed and to ensure that the ends of the pipe are square and free of burrs or sharp edges. After cutting, the ends of the pipe should be cleaned with a wire brush to remove any debris or corrosion.

This will help to ensure a good connection and a long-lasting seal. Finally, flux should be applied to the pipes before soldering to ensure that the parts are completely sealed and that no gaps remain.

With the copper pipe properly prepared, the next step is to connect it to the PEX pipe.

Connecting PEX to Copper

After preparing the copper pipes, it’s time to join them with the PEX, creating a tight, lasting seal. When installing PEX, it’s important to use the proper pipe sizing as this will ensure that your connection is secure.

Here are some key steps to connecting PEX to copper:

  • Securely attach the PEX fitting to the pipe.
  • Apply flux to the copper connection and heat the fitting with a torch.
  • Slip the PEX tubing onto the fitting and heat it with a torch.

Connecting PEX to copper requires some skill and care. It’s important to heat both the fitting and the PEX tubing evenly and for the right amount of time. When done properly, this will ensure a tight, leak-resistant connection.

Make sure to use the right tools such as a fitting brush and flux brush to ensure a clean and successful connection. Additionally, always wear safety goggles and gloves when heating and connecting the pipes to protect yourself.

Sealing the Joints

Once the fittings are securely attached, it’s time to seal the joints to ensure a watertight connection. To do this, you should use a special tape that is specifically designed for this purpose.

This tape is applied over the joint connection, which helps to prevent any leakage. You can also use soldering techniques to seal the joints, which is a more permanent solution.

In order to solder, you need to make sure the connection is clean, and then use a soldering iron and solder wire to create a waterproof bond. Once the soldering is complete, you should use a flux to help the soldering cool correctly.

This will create a watertight seal that will last for many years.

Pressure Testing the Connection

Now it’s time to pressure-test the connection to ensure it’s watertight. To guarantee water safety in the copper-to-PEX connection, it’s important to select the correct fittings and to properly pressure-test the pipe.

Before the test, make sure to double check that all the fittings are tight and secure. For the pressure test, use a pressure gauge and a pressure regulator to monitor the pressure. Start by adjusting the pressure regulator to the desired level, which should be around 10 psi.

Then, attach the gauge to the pipe and turn on the water. The pressure should remain steady at 10 psi for at least 10 minutes. If the pressure drops, you should tighten the fittings again and retest the connection.

Once the pressure is stable, turn off the water and check the pressure gauge. If the pressure drops after turning off the water, you should consider replacing the fittings and retest the connection.

With careful attention to detail, the connection should be watertight and safe for use.

Troubleshooting Common Issues

If the pressure test isn’t successful, there are a few potential causes – up to 70% of plumbing leaks are caused by improper fittings.

Before connecting your copper and PEX pipes, it’s important to make sure that you have the right tools and materials. Make sure to select the right tools for the job, such as a PEX crimper, a PEX cutter, a tubing expander, and a pipe-bending tool. Additionally, you should make sure that you have the right materials for the job, such as PEX tubing with an oxygen-barrier layer, brass PEX fittings, and copper fittings.

When connecting the PEX and copper pipes, it’s important to ensure that the connections are completely secure. If the connections are too tight or too loose, air may leak from the pipes, causing a pressure test failure. If you’re unsure of how tight or loose the connections should be, you should consult a professional to ensure that the connections are secure.

Additionally, it’s important to make sure that all of the connections are properly insulated to prevent condensation or moisture buildup.

Frequently Asked Questions

What type of glue can I use to connect PEX pipe to copper?

When installing PEX pipe to copper, it’s important to use the correct glue to avoid leaks. To ensure a secure connection, use Teflon tape or a specially formulated pipe thread compound to wrap the threads of the connection.

Then, apply a PTFE-based thread sealant to the male threads of the copper pipe. This will ensure a reliable seal and prevent leaks. Additionally, make sure to use a brush to apply the PTFE-based sealant, as it’s the most effective way to get an even coating.

Following these tips will help you install PEX pipe to copper correctly and avoid leakages.

How can I make sure the connection between PEX and copper is airtight?

You can ensure an airtight connection between PEX and copper by using soldering techniques.

With the proper tools and materials, such as a soldering iron, flux, and solder, you can create a permanent bond that will form an airtight seal.

To further ensure a tight seal, a pipe sealing compound can be used around the joint to provide extra protection against air and moisture.

With the right techniques and materials, you can ensure an airtight connection between PEX and copper.

How long does it take to connect PEX pipe to copper?

Connecting PEX pipe to copper can take anywhere from 30 minutes to several hours, depending on the complexity of the job.

It’s important to ensure a waterproofing seal is used to secure the connection and that the pipes are properly insulated.

To ensure an airtight connection, use an adhesive approved for use with your PEX and copper pipes, then wrap it with an appropriate pipe insulation.

Finally, be sure to follow all safety protocols, such as wearing protective eyewear and gloves, when making connections.

What tools do I need to connect PEX pipe to copper?

You need the right tools in order to securely connect a PEX pipe to copper. The most common technique is crimping, where a special tool is used to join the two pieces together. This is a relatively straightforward process and can often be completed with minimal effort.

For a more secure and permanent connection, soldering is the preferred technique. This requires more specialized tools such as a soldering torch and solder, as well as a heat-resistant material to protect the pipe from the heat.

With the right tools and knowledge, you can easily connect a PEX pipe to copper.

Are there any special considerations I need to keep in mind when connecting PEX to copper?

When connecting PEX pipe to copper, there are several key considerations that you should keep in mind. Proper soldering techniques are important, as any incorrect technique or use of the wrong materials can cause leaks.

Make sure that your clamp sealing is tight for a secure connection. Additionally, be sure to size your pipes correctly to ensure that the water pressure is not too high, as this can cause the connection to become loose.

Lastly, temperature control is key when soldering, as too much heat can damage the pipes. Following these tips will help you create a secure and successful connection between PEX and copper pipes.


You can absolutely connect PEX pipe to copper.

While the process may seem intimidating, it’s actually quite easy when you understand the steps. Just be sure to use the right connectors, prepare the copper pipe, and carefully seal the joints.

Pressure testing the connection is also essential to make sure the pipes are secure. Yes, it takes some time and patience, but the process is doable.

One common concern is that the connection won’t be secure. But if you follow the steps and use the right materials, your connection will be secure and long-lasting.

So don’t be intimidated – with the right tools and knowledge, you can connect PEX pipe to copper with confidence.

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