Steps for Substituting Copper Pipes with PEX

With more than twenty years of practical experience in renovating, repairing, and enhancing residences, Lee has been offering home improvement guidance for many years.

Project Summary

• Duration of Work: 1 to 3 hours
• Overall Duration: 1 to 3 hours
• Output: 1 substitute pipe

• Proficiency Level: Intermediate
• Projected Expense: Between $30 and $100

Significant renovation projects frequently require the removal of walls, floors, and ceilings, along with the examination of outdated plumbing systems and the replacement of copper pipes with PEX when needed. Inspecting water supply pipes is particularly important, as they transport water under pressure, and a major plumbing leak can lead to severe consequences. PEX is particularly advantageous for those who prefer to tackle projects themselves. It is simpler to handle compared to the conventional method of soldering copper fittings with a torch. While it is commonly utilized by professionals, DIY enthusiasts can easily grasp the fundamentals of substituting copper with PEX.

What does PEX refer to?

PEX is a flexible plastic tubing composed of high-density cross-linked polyethylene. Known for its strength, flexibility, and resistance to corrosion, PEX was introduced in Europe during the 1970s.

Reasons to Transition from Copper to PEX

In the past, upgrading water supply pipes typically involved the installation of new copper pipes, which were connected using sweat-soldered fittings that required a flame torch and a high level of expertise. From the 1950s until 2000, copper was the preferred material for plumbing, commonly used in both new builds and as a replacement for the galvanized steel pipes that were the norm prior to the 1950s. However, the popularity of copper has diminished over time, largely due to the emergence of PEX plumbing tubing. Introduced in the United States in the 1980s, PEX has become the material of choice for many plumbing applications for a variety of reasons.

Reduced Risk

PEX offers flexibility and requires fewer connections and fittings. This decrease in necessary fittings in a PEX system lowers the risk of leaks. Furthermore, PEX is resistant to corrosion and does not form pinholes, a problem often associated with copper piping.

Reduced Expenses

PEX is more affordable than copper, and the installation expenses are reduced when done by professionals. Moreover, PEX pipes are usually joined using crimp-ring connectors, which need a low-cost crimping tool, or push-fit connectors, like the well-known SharkBite fittings. Both techniques are suitable for connecting new PEX pipes to existing plumbing, but push-fit connectors are particularly popular with DIY enthusiasts since they do not require any specialized or expensive tools.

Enhanced Longevity

PEX consists of cross-linked polyethylene, a type of flexible plastic pipe characterized by interconnected molecules, which provide exceptional durability and strength.

Resistance to Freezing

PEX offers greater resistance to freezing compared to other rigid plumbing materials. While it can freeze at temperatures below 20 degrees Fahrenheit, it is less prone to bursting than traditional rigid pipes.

Prior to Starting

When installed correctly, copper pipes can last for over 50 years. Copper is an excellent choice for construction materials and is commonly used in roof and chimney flashings. Pipes that appear green and corroded may not require replacement, as their appearance does not always indicate a need for change.

However, copper pipes will deteriorate over time. If you have original copper pipes, they might be approaching the end of their functional life, and identifying the right moment for replacement can be challenging. Initially, when copper pipes begin to corrode, they might not leak significantly, making the issue less apparent. Nevertheless, there are some early indicators to watch for. Any combination of these signs suggests that your copper pipes are deteriorating.

• Odor: As time passes, you may start to detect a lingering, damp scent that is difficult to pinpoint. This can be particularly perplexing in areas like a laundry room, bathroom, or a child’s bedroom, where you might instinctively associate the odor with the space itself. However, the scent resembles that of stagnant water, reminiscent of a still pond. This kind of odor could potentially be the result of leaking copper pipes hidden within the walls or ceiling.
• Issues with walls or ceilings: Large bulges may begin to appear on ceilings or walls. This could be a result of tiny leaks in copper pipes that are gradually dripping onto the drywall, leading to its swelling. Additionally, water can originate from various other sources. Roofs, gutters, and drainpipes can also contribute to moisture in walls and ceilings, independent of copper plumbing.
• Corrosion: When you access a wall or ceiling for reasons like installing insulation, you might observe that the copper pipes within the wall or floor space have developed a green, crusty appearance and show signs of corrosion. These pipes might even have tiny pinhole leaks that are starting to seep water, although the dripping may not be noticeable just yet.

Tip

Understand how to recognize corrosion in copper pipes. Joints in copper pipes that have been soldered using a blowtorch often exhibit a braised, charred, or silvery look. This is a typical characteristic and is not indicative of corrosion.

Requirements for Your Task

Gear / Instruments

• Marker
• Copper pipe cutter
• Drill-driver
• Copper pipe burr removal tool
• Measuring tape
• PEX pipe cutting tool
• Wrench

Materials

• PEX pipes
• Straight couplings with a push-fit design
• Push-fit connectors (as required)
• Copper pipe clamps and screws (if required)

Instructions

Steps for Substituting Copper Pipes with PEX

Shut Off the Water Supply

Turn off the water supply. Since the pipes carry pressurized water, it’s essential to stop the flow and drain the pipes before beginning any work. Your plumbing system might have individual shutoff valves that enable you to isolate the specific section you’re repairing, or you can opt to close the main shutoff valve to stop the water supply to the entire house while you carry out the repairs.

Empty the Pipes

To empty the pipes, turn on a faucet located at the lowest point in your house, like a basement sink or a utility sink or bathroom on the first floor. This action will help remove any leftover water, relieve water pressure, and minimize any potential spills when you make cuts in the copper pipes.

Trim Both Sides of the Copper

• Label the copper pipe to show the portion you intend to replace. Ensure that the area you are replacing extends significantly beyond the corroded sections on both sides.
• Employ a copper tubing cutter to slice through the copper pipe at each end of the segment that needs to be replaced. A compact tubing cutter is an ideal tool for working in confined spaces.
• To prevent vertical pipes from slipping into wall cavities, it is essential to provide proper support. Before making any cuts, fasten the vertical pipes to the wall or floor framing using copper pipe straps and suitable screws.

Trim the Supply Lines for Fixtures

• Cut the supply lines. When removing a section of copper pipe that has branch lines leading to plumbing fixtures like toilets, sinks, showers, or bathtubs, it’s necessary to cut these connections using a tubing cutter. If the branch connections are made with couplings or compression fittings instead of soldered fittings, use a wrench to disconnect them.
• Consider using this chance to swap out the copper supply lines for PEX. If you decide to do this, be sure to take out the copper lines as well. If you prefer not to replace them, you can keep them for reconnecting to the new PEX tubing.

Smooth the Edges of the Copper Pipe After Cutting.

Make the cut edges smooth. For the push-fit connectors to fit properly, the cut edges of the copper pipe must be completely smooth and free of debris. Even if the pipe appears to be smooth upon visual inspection, it’s advisable to use a de-burring tool to ensure a clean finish.

• Utilize a copper deburring tool to refine the edges of both the interior and exterior of all cut copper pipes.
• Move the tool a few inches along the pipe to ensure that all corrosion has been eliminated.

Trim a section of PEX pipe.

• Make sure to consider any additional length contributed by the push-fit connectors.
• Trim the PEX tubing a bit longer to provide space for expansion and contraction. The flexibility of PEX tubing allows for a bit of extra length.

Join the PEX to the Copper.

• Prepare the end of the PEX tubing by eliminating any burrs or contaminants.
• Determine and indicate a depth line at the end of the tubing, adhering to the guidelines provided by the push-fit connector manufacturer; repeat this process at both ends of the copper pipe.
• Attach one end of a push-fit straight connector to one of the severed ends of the copper pipe.
• Ensure that the pipe is completely inserted into the bottom of the connector, and that the connector aligns with the depth marking. Place one end of the PEX tubing into the remaining opening of the straight connector, pushing it in until it reaches the depth line.
• Perform the same procedure on the other side of the repair zone, connecting the PEX to the copper pipe using an additional push-fit straight connector.

Tip

For added convenience, consider using a push-fit ball valve in place of a straight connector, allowing for an easy shutoff in this part of the water supply system. This valve will typically remain in the open position and will only be utilized when the pipes require a shutdown for maintenance. It’s important to note that regulations stipulate shutoff valves must be installed in accessible areas, so avoid placing a shutoff valve in a wall cavity that will be sealed after the repairs are completed.

Attach the supply lines of the fixture to the PEX tubing.

Connect the supply lines. If the section of copper that was taken out was supplying lines to fixtures, you will need to link those supply lines to the new piece of PEX.

• Use a PEX tubing cutter to slice through the PEX line, and then connect a push-fit tee fitting to join the line.
• Two connections on the tee link to the PEX pipe, whereas the third connection supplies the line that leads to the fixture.
• If desired, the copper supply lines for the fixture can be substituted with PEX at this moment.

Three Tiers of Replacing Copper Pipes with PEX

If you encounter corroded or leaking copper pipes while working on your remodeling projects, you have a range of DIY PEX installation choices available, varying from the simplest and most affordable to the most complex and costly.

Perform Localized Repairs on Copper Using PEX

If you discover leaking copper pipes, you might opt for a minimalistic solution by removing the damaged section and substituting it with PEX. In many cases, you can simply install a single push-fit connector in the affected area. Spot repairs on copper pipes are a common occurrence in older homes.

Substitute Exposed Copper Areas with PEX

To strike a balance between fully re-piping the house and making minor repairs, consider replacing substantial lengths (10 feet or more) of visible copper piping with PEX, extending it as necessary.

Many DIY enthusiasts opt for replacing visible sections of piping, as this approach is less daunting and more budget-friendly than re-piping the whole house. Although it may seem intricate, this method is not significantly more challenging than making localized repairs. This is due to the fact that you are extending the existing pipe as far as you can, rather than just addressing a specific area.

Substitute all copper with PEX.

Disregarding expenses, the most effective long-term approach is to completely re-pipe your residence, substituting copper pipes with PEX. This process entails disconnecting and rerouting all existing copper pipes and installing new PEX lines throughout the property. You have the option to maintain the existing layout or implement a new PEX manifold-and-branch configuration. Additionally, as part of the project to replace the metal pipes with PEX, it will be necessary to re-establish the grounding of your electrical system.

Ensure that your electrical system has proper grounding.

One consequence of replacing your metal plumbing pipes with PEX pipes is the elimination of a grounding point for the electrical system of the house.

In residences featuring outdated electrical systems, grounding is occasionally achieved via metal water pipes. This method is less prevalent in modern circuit breaker systems, which are typically grounded correctly upon installation. However, it is more frequently observed in older systems that rely on fuses for protection instead of circuit breakers.

When substituting metal water pipes with PEX, the continuous grounding pathway could be disrupted, as plastic pipes do not conduct electricity.

Furthermore, regulations in certain areas might stipulate that the complete plumbing system must be connected to the home’s grounding system. In this case, switching from copper to PEX could disrupt that connection. It is advisable to reach out to local code officials for guidance on managing bonding in plumbing systems that utilize PEX.

When to Seek Professional Assistance

Due to the significance of grounding concerns, it’s advisable to consult a professional to ensure that your system remains adequately grounded when switching from metal to plastic plumbing pipes. If you discover that outlets have lost their grounding, it’s best to seek the assistance of an electrician to restore the grounding. Typically, this involves linking the main service panel to a grounding rod that is installed in the ground, using a bonding wire.

Is it beneficial to swap out copper pipes for PEX?

Replacing aging copper pipes with PEX is often a beneficial choice. PEX offers greater reliability and longevity over time.

What is the expense involved in converting copper to PEX?

The average expense for converting copper to PEX, including materials and labor, typically ranges from $2.50 to $8 or higher per linear foot. For a project involving 500 linear feet, the total cost could vary from $1,250 to over $4,000.

Which material do plumbers favor more: copper or PEX?

Although copper pipes and fittings remain prevalent, a growing number of professional plumbers are opting for flexible PEX in new constructions and for the majority of repairs and upgrades to existing copper systems.