Replacing Oxidized Copper Pipes with PEX

A customer recently contacted McPipe Plumbing after noticing oxidation on sections of copper piping in their home. The green buildup was concentrated around several connections, and the customer decided to have the affected piping replaced with PEX.

The old copper sections and fittings were removed, new PEX water lines were installed, and the system was tested under normal water pressure.

What Causes Oxidation on Copper Pipes?

Copper naturally reacts with oxygen and moisture over time. This can produce green or blue-green discolouration on the outside of the pipe, particularly around fittings, valves and soldered joints.

Discolouration does not always mean a pipe needs immediate replacement. However, heavier buildup around a connection may be related to condensation, previous water exposure or a slow leak. Copper can also become thinner as it ages, eventually developing pinhole leaks or weakened sections.

In this case, the customer chose to replace the affected copper piping before the condition became a larger plumbing problem.

Removing the Affected Copper Piping

The first step was to shut off and drain the water lines. The oxidized copper sections and older fittings could then be cut out while leaving the usable piping in place.

Removing only the affected sections can be an option when the rest of the plumbing remains in good condition. More extensive repiping may be recommended when corrosion or recurring leaks are found in several areas of the home.

Why Replace Copper Pipes with PEX?

PEX is now commonly used for residential water lines. It is a flexible plastic piping material that can be routed through joist spaces and around obstacles with fewer fittings than rigid copper.

A homeowner may choose PEX because it:

• Does not develop the same type of oxidation as copper

• Requires fewer elbows and soldered joints in many installations

• Can be easier to route through tight or finished areas

• Is less likely to burst if briefly exposed to freezing temperatures, although it is not freeze-proof

• Can be used to replace an individual damaged section or for a larger repiping project

• Is often more economical than replacing the same amount of piping with new copper

The right material and installation method depend on the location of the piping, the existing plumbing and the condition of the surrounding lines.

Connecting the New PEX Lines

The new PEX piping was routed through the existing joist space and connected to the remaining copper lines using approved transition fittings.

The lines needed to be properly supported and positioned away from sharp edges or other surfaces that could damage the piping. The connections were then checked carefully after the water supply was restored.

Testing the Completed Pipe Replacement

After the new piping was installed, the system was tested under normal water pressure. The transition fittings, PEX connections and remaining copper piping were inspected for leaks.

Testing is an important part of any pipe replacement. A connection may appear secure while the water is off but still need adjustment once the system is pressurized.

When Should Copper Pipes Be Inspected?

Consider having copper piping inspected if you notice:

• Green or blue-green buildup around joints and valves

• Water stains beneath exposed pipes

• Dampness around a fitting

• Pinhole leaks that continue appearing in different locations

• Corroded shut-off valves

• Reduced water pressure

• Plumbing that has already required several repairs

One problem area does not necessarily mean every copper pipe in the home needs to be replaced. An inspection can help determine whether a localized repair is sufficient or whether a larger section of the system should be addressed.

Copper Pipe Replacement and PEX Repiping

McPipe Plumbing repairs and replaces damaged water lines throughout Thornhill, Vaughan and nearby GTA communities. Depending on the condition of the plumbing, the work may involve replacing one corroded section, upgrading older valves and fittings or repiping a larger area with PEX.

If you have noticed oxidation, moisture or recurring leaks around your copper pipes, McPipe Plumbing can inspect the affected area and recommend the appropriate repair.