How to Connect PEX to Copper Pipe: 2 Easy Methods

Connecting PEX (cross-linked polyethylene) to copper pipes is a common task for DIY plumbers and professionals alike. While the traditional method involves soldering, there are now easier ways to splice the two materials together. In this article, we’ll explore two simple techniques to connect PEX to copper pipe, whether you’re working with threaded or non-threaded ends.

Method 1: Using Push-Connect Fittings

Push-connect fittings are a convenient way to join PEX to copper without the need for soldering. These fittings have an internal o-ring and teeth that grip the pipe, holding it in place securely. Here’s how to use them:

Mark the depth on the copper pipe using a depth gauge or marker
Insert the push-connect fitting and push it to the marked depth
Attach the PEX pipe to the other end of the fitting
Push the PEX until it reaches the stop, creating a watertight seal

Push-connect fittings are easy to install and can be a great option if you want a quick, solderless connection. However, some building codes may not allow these fittings to be buried in walls, so be sure to check your local regulations.

Method 2: Using Sweat Adapters

If you prefer a more traditional approach or need to comply with building codes, you can use sweat adapters to connect PEX to copper. This method requires soldering the adapter to the copper pipe before attaching the PEX. Here’s how it’s done:

Cut the copper pipe to the desired length and deburr the inside and outside
Clean the pipe and adapter with emery cloth or a grit pad
Apply flux to the pipe and adapter, then solder them together
Attach the PEX to the other end of the adapter and secure it with a crimp ring or clamp

Sweat adapters provide a strong, permanent connection that is suitable for use in walls and other concealed spaces. The soldering process may take some practice, but it’s a reliable way to join PEX and copper pipes.