Installing plumbing is a time-consuming process, especially when it’s done using traditional plumbing materials. Galvanized steel and copper pipe are commonly used for water supply plumbing, but PEX recently began upstaging the two. The flexible material makes it much easier to finish the job, saving hours.
Although PEX is the convenient choice, are the push fittings often used to connect pieces of PEX reliable? Convenience is great, but regularly dealing with faulty fittings and leaks isn’t. We did the research for you, so stick around to learn more!
What Is PEX?
Cross-linked polyethylene, also known as PEX, is a type of flexible plumbing. The material consists of cross-linked plastic that forms a supple, flexible result. German scientist Thomas Engle discovered a way to create this material in 1968, but it didn’t arrive in the US until the 1980s.
Originally, PEX was used for radiant floor heating systems. While it remains a popular choice for radiant floor heating systems, PEX is also popular for plumbing. In Europe, PEX in water supply systems has been widespread since the 1980s, but the US is a bit slower to the punch.
Earlier versions of the material didn’t hold up well under exposure to high chlorine levels, making it an unsuitable choice for most US water supplies. On top of that, early PEX systems often had issues with failed and leaking fittings, making it a nuisance to install and repair.
However, time and plenty of research solved these problems, making PEX a go-to pick for many scenarios. Today, about 60 percent of new construction residential water supply systems use PEX tubing.
How Do PEX Push Fittings Work?
Push fittings are a type of quick-connect fitting that makes plumbing fixes and installations much more straightforward, especially for less experienced individuals. Popular brands like John Guest and SharkBite fittings are the better-known options on the scene, although John Guest fittings tend to be more trusted due to the length of time they’ve been on the market.
Push fittings are relatively simple in how they work. There are slight differences in each brand’s design, but the general concept remains the same. The fitting features a collet and an O-ring within the body.
The collet’s grip is made up of metal teeth that secure the pipe, and the O-ring creates a watertight seal to prevent leaks. Once you push the pipe or tubing into the fitting, the teeth clench down, securing the pipe in place.
Some of these fittings are made of brass, while others are composed of plastic. Plastic fittings are usually the ideal choice for plastic tubing, as both materials are flexible and give with each other.
While SharkBite fittings simply have teeth that hold the tubing in place, John Guest fittings also have a locking mechanism in addition to a few teeth in the collet. The mechanism features a twist-lock design that prevents the connection from disconnecting when the water flow abruptly stops.
John Guest fittings are removable and will allow you to repair the fitting, but SharkBite fittings don’t allow this luxury. You can remove the collet in a John Guest fitting if there are issues, but you can’t do the same with a SharkBite fitting.
Are PEX Push Fittings Permanent?
PEX push fittings can be permanent, although most plumbers prefer soldering over these fittings. Soldering is known to provide a more secure and permanent connection, but this doesn’t mean you can’t use PEX push fittings as a permanent solution.
Most push-fit fittings are authorized for underground or in-wall applications, meaning they’re suitable for permanent installation. Given their relative newness on the scene, many folks are skeptical of the reliability of these fittings, especially in settings when they’re concealed.
Are PEX Push Fittings Reliable?
There are mixed reviews when it comes to PEX push fittings. Some folks feel push fittings are equally reliable as soldering, while others vehemently disagree. That said, most professional plumbers recommend only using push fittings for emergencies and temporary use, as many don’t consider them a permanent solution.
When a PEX push fitting fails, a user error usually causes it. Without the proper installation, the fitting is bound to fail. As long as you follow the right instructions and ensure the tubing is squarely cut, there shouldn’t be any issues.
Ultimately, the decision to use PEX fittings in concealed settings is yours. Many professionals advise against using these fittings in concealed or underground settings as you won’t immediately notice if the fitting fails. On top of that, many experts advise against using SharkBite fittings outside since the sunlight can dry out the O-ring and cause it to crack or split.
We recommend soldering the connections if possible, especially for concealed installations. If you’re not experienced with plumbing connections, it’s best to outsource the job, as a failure here can be catastrophic. Of course, it might not be the cheapest solution upfront. However, in the long run, you might spend more to repair faulty areas of the system than you would have to hire a professional.
Again, the decision is yours, and while PEX fittings are decently reliable when properly installed, we don’t recommend using them for permanent installations.
Tips For A Successful Push Fitting Installation
Installing a push fitting is a simple process, but the fitting could fail without following the correct steps. Here are a few tips to help ensure a successful installation:
- Use a pipe cutter: Avoid using a hacksaw, as this can create burrs or scratches on the tubing, preventing the O-ring in the fitting from sealing. This also helps create a square cut, ensuring there won’t be slanted portions that could leak.
- Use the right disconnect tool: Select the properly sized disconnect tool. An incorrectly sized tool will prevent the fitting from working with the tool.
- Clean the tubing: Dirt, dust, and grime could prevent a solid seal, so clean the tubing before making the installation.
- Use undamaged tubing: Avoid using compromised tubing. Scratches, dings, and divots could allow the fitting to leak, so choose unmarred tubing for your project.
- Push the fitting all the way: Slowly push the fitting into place, ensuring it seats properly. Don’t shove the tubing in too quickly, as jamming it into place could damage the O-ring, allowing the pipe to leak.
Use the right insert: Since PEX pipes are flexible, they can collapse inside the fitting. You’ll need to use an insert to prevent the pipe from collapsing. Certain brands, like SharkBite, build this into their fittings, so you won’t need an additional insert. However, if you use a different brand, ensure you use an insert.