When Should You Replace Copper Pipe With PEX?

Beginning in the 1950s and 1960s, copper was the plumbing material of choice in American homes. It was used for new homes and to replace the galvanized iron pipes that had been in use until then. However, PEX piping is the new kid on the block, so should you replace your copper piping with PEX?

Should I replace my copper piping with PEX, I hear you ask? If there is nothing wrong with your existing copper piping, there is no need to rip it out and replace it with PEX. However, if you are experiencing leaks or are remodeling a home with plumbing that is over 50 years old, then PEX could be a good option, especially if you are doing the work yourself.

What Is PEX Pipe?

PEX is cross-linked polyethylene flexible tubing, and it is used for plumbing in the same places copper has traditionally been used.

It is usually sold in rolls of 50 feet up to rolls of 1,000 feet or more. For residential use, you will find PEX tubing from 3 / 8 of an inch to 1 inch in diameter.

Which Is Better Copper Pipe Or PEX?

Neither copper nor PEX is inherently better than the other.

Each one has advantages and disadvantages which make one better than the other, depending on:

  • How much pipework you are replacing.
  • Whereabouts in your home, the pipes you are replacing are located.
  • Why you are replacing your pipes.
  • Which material your existing plumbing is made from.
  • Who is carrying out the work
  • Whether you are connected to city water or a well.
  • The acidity of your water.
  • Your budget.

What Are The Advantages Of Copper Pipes?

Copper pipes are a known commodity. The Egyptians were the first to use copper pipes, and the Romans had copper pipework for their drinking water and cisterns. Copper pipes have been used in American homes since the 1950s, and by the 1960’s it had become the standard plumbing material.

Consequently, we are very familiar with the properties of copper plumbing, how it behaves, and the effects on human health.


In areas where piping is exposed, copper pipes are more aesthetically pleasing them PEX. 

What Are The Disadvantages Of Copper Pipes?

Copper pipes are significantly more expensive than PEX. Not only that, but because copper requires more skill and more time to install, labor costs for the installation of copper pipes are higher.

Up to 60% of the copper piping available today is, at least partly, manufactured from recycled materials.

What Are The Advantages Of PEX Pipes?

The most significant advantage of PEX over copper is the price, but there are other major advantages, including:

  • PEX pipes do not erode in the way that copper pipes can, and although they can still freeze, PEX pipes will not burst after freezing and cause flooding.
  • Because of their flexibility, it is easier to feed PEX pipes behind drywall or under flooring.
  • Installing plumbing in a home involves running pipes in sometimes difficult to access places. You have to change direction, move around corners, and copper pipes require lots of measuring, cutting of pipes, and connecting the pieces with copper elbow joints.
  • PEX tubing is flexible. You can change direction, thread it behind joists, and curve it around corners without the need to repeatedly cut lengths of pipe and affix connectors.
  • When making connections or repairs in copper pipes, you have to clean the ends, use a copper joining fixture, and solder it in place. With PEX pipes, you can use simple push fittings or easily used crimp connectors.
  • With traditional copper pipework, cut-off valves will usually be installed close to each sink, shower, baths, toilet, and appliance. When you install a complete PEX plumbing system, individual pipes run directly from your taps, or other outlets, to a distribution manifold.
  • This is like an electrical panel for your plumbing. Each pipe enters the distribution manifold at a point with a label. The label will tell you where the pipe goes. If you have an emergency or have to carry out any maintenance or repairs, the water can easily be turned off at the manifold.
  • To make it incredibly easy to install a PEX system, the pipe comes in blue, red, or white. Apart from the color, all three types of pipe are the same. However, using blue pipes for cold water and red pipes for hot makes it easy to remember which pipe is which when you are connecting it to either the hot or cold water supply.

What Are The Disadvantages Of PEX Pipes?

PEX has been in use for the last 30 years or so, and although there have been plenty of studies in this time to show PEX is safe for human use, we still do not know for sure what any long-term health effects may be.

There is also limited information about how well it will stand up to decades of use in the home and how frequently it needs to be replaced as part of general home maintenance.


PEX can be damaged by the sun, becoming brittle after sustained exposure to UV light. For this reason, it is not suitable for use outside in locations where it will be in the sunshine. 

While PEX does not erode, it is susceptible to rodent damage, a small but essential consideration if you are replacing pipes in an area known to have pest problems.


PEX pipes can contaminate the water they carry. This usually happens if the water has been standing in the pipe for a sustained period. To minimize the risk of any unpleasant tastes or smells, if your systems have sat unused, run the water for ten minutes to clear the pipes.

In addition, environmental contaminants such as pesticides are more likely to permeate PEX piping than they are copper pipes.


Fittings for PEX pipes are more expensive than those used for copper. Consequently, unlikely though it is, replacing a small length of pipe with multiple fittings could become more costly than using copper pipe.

Fire Damage

Copper pipes stand up well to small fires, while PEX pipes are more likely to melt or be damaged in some way.

Heat Resistance Issues

While PEX can carry hot water, the heat from your boiler may cause the pipe to deform or fail. Consequently, the last, small length to your water heater should always be copper or steel braided pipe.

Should I Replace My Copper Pipes With PEX?

Now you know the pros and cons of each type of pipe, it’s time to circle back around to the question we began with – Should you replace your copper pipes with PEX?

The first thing to know is that PEX and copper pipes are interchangeable. If you have a small leak, fittings are available that connect to both copper and PEX so you can replace a stretch of copper pipe with a length of PEX. 

When To Replace Your Copper Pipes With PEX

As PEX is more affordable and easier to work with than copper, if you are making a small repair yourself, it makes sense to replace a copper pipe with PEX. 

Also, if you are running a new length of pipe to a new area of your home, then you can connect PEX to the copper pipe at an easy to access point and run the PEX behind the walls much more easily than you can run copper.

If you have an older home and are remodeling AND you know that your copper piping is well over 50 years old, it makes sense to replace your copper piping with PEX while you are opening up walls or pulling up floors.

Doing so will allow you to run separate lengths of pipe directly to individual appliances, fixtures, and fittings and to install a distribution manifold. This, in turn, will make it easier to shut off the water to a specific point should you need to do so in the future.

When Not To Replace Your Copper Pipes With PEX

If there is nothing wrong with your existing plumbing, there is no advantage to replacing your copper pipes with PEX. It is an unnecessary expense with no tangible benefit.

In addition, if you have an older home that has copper piping and the “period correctness” of your home is important to you, or your home’s value may be negatively impacted by changes, then do not replace your copper pipes with PEX.

Finally, if you live in an area where the water has high levels of chlorine, copper pipes will last longer than PEX.

Final Thoughts

There is no reason to proactively remove and replace copper pipes if you are not experiencing any problems. 

If you are carrying out renos, making significant repairs, or experiencing issues with your copper pipework, then PEX is an affordable alternative replacement material that has many advantages.

However, there are some circumstances where it is preferable to retain copper piping, so ensure you make the decision with the unique needs of your home and family at the fore.



Geoff Southworth is the creator of RealEstateInfoGuide.com, the site that helps new homeowners, investors, and homeowners-to-be successfully navigate the complex world of property ownership. Geoff is a real estate investor of 8 years has had experience as a manager of a debt-free, private real estate equity fund, as well as a Registered Nurse in Emergency Trauma and Cardiac Cath Lab Care. As a result, he has developed a unique “people first, business second” approach to real estate.

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