PEX is a great material if you want to install indoor plumbing. Sometimes you want to keep the existing copper pipes though. Connecting both is quite easy as you can just solder a special attachment to the copper pipe. In some places, it can be hard to solder though. Even if you don’t want to solder, it is possible to get this done. Let’s take a look at how this can be done.
Make sure to wear appropriate protection (such as gloves and goggles) when you do this work. It is also important to close the water supply valve and drain the pipes before you start.
A fitting is a connector between two pieces of pipe. They come in different diameters and you have to check the diameters of your pipes to make sure that you get the right ones.
Recently push-on connections such as Sharkbite or Viega have been introduced. These make it easy and fast to connect copper pipes with PEX.
You just have to slide the pipes in the fitting. In some instances, you will get an indication that the fitting is properly installed. There are grippers that slide out of the fitting and connect to the PEX and copper pipe. This should create a waterproof connection if you push them hard enough.
It is important that you debur your copper pipes (eg remove the sharp edges) before you slide on the fitting. You can use a deburring tool or a knife for this. Make sure that the pipes are clean and no residue is found inside of them before using the fitting. You can use sandpaper to do this. You should also use the calibration tool for PEX so that the pipe is perfectly round.
Read the instructions carefully before you start and check your local code to see what is possible. Some plumbers argue that these fittings are not as durable as soldered connections. Tests seem to indicate that some brands offer push-on fittings that last a long time. Don’t go for cheaper brands as these might not be up to code.
Sharkbite has a lot of connectors so you have to make sure that you get the right one. It has to be able to connect PEX with copper and also should have the right diameter. Double-check this before you get one. If you are not sure which one you should get, you can always ask for help in your local hardware store. They should be able to point you in the right direction.
Push-on fittings can be more expensive than using soldering but it can be faster to install them.
The cost of a Sharkbite fitting will vary depending on the size. They typically run from $2 to $8, with the average costing about $4. It is important that you check if the connection is being made and test the fitting. Plumbers also test their system by adding water and seeing if the pressure drops after a while. Leaks should be avoided at all costs.
If you made the connection in the wrong place, you can simply cut a piece of pipe and remove the connector. Then you can add another fitting on the pipes. You should throw away the used fitting as it is not possible to reuse it.
Adding a Manifold
If you have more space, it can be a great idea to add a manifold. This is a divider piece that allows you to connect multiple PEX pipes to it. Most manifolds come with dedicated connectors for both copper and PEX. This makes it very easy to connect them as you can use the same methods as you have used before. You can use the traditional ways of connecting copper with each other (as discussed here) and then just connect your PEX pipe to it. We have outlined the differences between installing PEX-A and PEX-B here. For PEX-A, we will typically use an expansion fitting with a PEX expansion tool. For PEX-B, we will often opt for a crimp fitting that will be installed with a PEX crimping tool.
The advantage of a manifold is that it adds flexibility. You can close some connectors. If you later decide that you want to add another faucet or water supply pipe, you simply open one of these connectors and add a PEX pipe. This is a great advantage as you don’t know how your needs might evolve in the future. For example, if you want to change the location of the washing machine, it is a lot easier if there is already a water supply available.
A manifold also makes it easier to make repairs in your house as you can cut the water supply to a specific faucet. If you don’t have this, you might have to cut the water supply to a big part of the house.
Adding a manifold generally takes less than 30 minutes. They range in size from a few connections to very large ones. Just make sure that you have enough water pressure when you install this. This can be hidden in a closet or behind a wall.
Remove the copper pipe
If you didn’t like the first two options, you can also decide to remove the copper pipe and replace it with PEX. This is done with a copper pipe cutter. You can then use a PEX pipe to replace this part of the installation.
You can also learn to solder and add a connector this way. This is discussed in the video below:
To conclude, we can state that connecting PEX with copper is quite straightforward. There are special systems that allow you to slide them into a connector. This provides a waterproof connection without soldering. It is important that you test the connection though. If this solution didn’t work for you, it is also possible to add a manifold. This is a water distribution system that makes it easy to attach copper and PEX pipes.