PEX vs Copper Pipe

Copper Pipes vs PEX Pipes
PEX vs Copper Pipes

The plumbing is a very important component of the overall health of your house. Pipes are so vital, they remind us of the blood vessels in our bodies. Without properly functioning pipes, our house and we would be in big trouble.

Fixing plumbing problems like replacing freshwater plumbing pipes are the last thing any homeowner wants to do. It is an expensive and painful task. In case you are confronted with re-piping your home dilemma, most likely your plumber will give you these two popular options: Copper or PEX.

If you’re wondering about the advantages and disadvantages of PEX and Copper pipes are, this article will provide you with some useful information.

Choosing the right type of piping for your plumbing is sometimes easy to underestimate. At a quick look, it may not seem so important which one to pick. If both PEX and Copper pipes are durable enough and can safely move the water through a system, each one must be fine, right?

It’s not so easy. While both copper and PEX piping will be adequate, each has its advantages and disadvantages. Choosing the one that is best suited to your particular needs will make your life much easier, your project a success, and may save you money today and even in the long run.

In this article, we will discuss the factors you need to take into consideration when deciding which sort of piping to choose from. But first let’s get to know more about the subject matter: PEX and Copper.

What is PEX?

PEX, aka cross-linked polyethylene, is a strong semi-rigid plastic material. Although PEX might look like a regular plastic to your eye, the science behind it is impressive! To create this unique high-density polymer, German scientist Thomas Engle found the way in 1968 to crosslink common plastic (polyethylene) through radiation to produce a better form of the material. This method of production made PEX so reliable that in many cases it can last longer than both copper and CPVC. The new flexible plastic has arrived in the USA in the 1980s.

By the way, we should not confuse PEX with polybutylene (PB). PB material was basically a failure and several class-action lawsuits have been filed against its manufacturers in the past.

PEX plumbing is great for various radiant and hydronic systems, both residential and commercial. It has been approved for normal pressures in plumbing and radiant systems by all major agencies and regulatory authorities. PEX was designed for potable (or drinkable) systems that have been used in the USA for years now. Actually, cross-linked polyethylene first entered the market in 1993 but only became a plumbing industry-standard in the last decade. Now, PEX is widely used and promoted for various projects, including building modern condos.

PEX pipes are manufactured in three colors: white, red and blue. It is done to assist plumbers and homeowners in installing the product more efficiently. The red color PEX pipes are intended for hot water, blue pipes are for cold water, and white color is for any temperature. No matter what the color of the pipe is, it is the same PEX pipe. The pipe’s color is only given for consumers’ convenience.

Like any other building product, cross-linked polyethylene (PEX) has its strong and weak sides.

Pros of PEX:

  • PEX is a great value: it is much cheaper than copper.
  • PEX is more freeze-resistant than copper because it is more flexible.
  • PEX pipes are easy to install. Its flexibility helps a lot because it does not require a torch to bend it.
  • PEX pipes do not corrode like copper or steel pipes. It’s not subject to problems with acidic soils or aggressive water.
  • PEX pipes produce less noise during operation than metal pipes.
  • PEX does not have problems with stray voltage or improper electrical grounding. It can be installed in a central manifold, similar to an electrical system.

Cons of PEX:

  • PEX is not suitable for outdoor use because PEX is extremely sensitive to UV light (sun). PEX pipe left outdoors will harden and crack within months. Copper pipes, on the other hand, can be used in areas exposed to natural light.
  • Like other plastics, PEX may leach BPA and other toxic chemicals into the water.
  • The ultimate bursting pressure of PEX is less than the bursting pressure of copper.
  • Unlike copper, PEX cannot be installed in high heat areas.
  • Although installation is relatively easy and DIY-friendly, working with PEX requires special connectors and tools.
  • Research has found that Legionella grows faster in PEX than in copper pipes.
  • Nails can damage PEX pipes (but the copper is not an exception here).

Note: There have been scattered reports of failures of this piping for various reasons, but no clear evidence of massive failure at this time. To be exact, the new research has shown that some PEX “B” piping might be having structural failures (for example, in some public-housing projects). However, the good news is – this does not affect types A or C of the PEX piping that are more common.

What is Copper Pipe?

Copper is a remarkable metal that is also used for piping water supply lines. The copper pipe, also known as a galvanized pipe, is a rigid tube made of copper. Copper pipes have been the long-term standard for plumbers all over the world. They have been using copper pipes and fittings for many years. Copper plumbing requires a certain range of funnels and fittings to put the system together.

Millions of homes have plumbing systems built with copper pipes and most had a very satisfying experience with them. However, the copper is 60% more expensive than the PEX. That’s quite the difference! Still, most plumbing stores globally always keep the copper pipes available due to their high demand.

Pros of Copper:

  • Copper pipes are amazingly durable and are known to last for decades (up to 70-80 years).
  • Copper is more heat resistant than many materials, including PEX and other plastics.
  • Copper resists bacteria growth. The common characteristics of copper make it resistant to the development of microbes inside it.
  • Another great feature of copper is that it won’t degrade in UV light.
  • Unlike plastic pipes, copper pipes can be used in areas exposed to natural light (outdoors).
  • Copper can be recycled and reused and in new pipes, fittings and funnels.
  • Copper is generally safe for water consumption because it does not erode much (however, it still can leach into the water).

Cons of Copper:

  • Copper is much more expensive than many other types of plumbing pipes. Installing copper piping also involves a higher cost (due to higher skill requirements, the need for special tools, etc.). Also, due to copper’s high value and its ability to be reused, copper can often become a target for thieves who cut and steal those pipes.
  • Copper is inclined (more than PEX) to freezing and bursting in a cold climate.
  • Unlike plastic, copper pipes can rust.
  • Copper pipes could have problems with acidic water (of the well, for instance).
Piping Repair PEX Copper Pipes

Pipes’ Usage Tips:

The damage may occur to piping during installation or when the pipes are frozen. Fixing the issue is done by removing the broken part and replacing it with the new pipe.

Plumbers find it easy to join the PEX pipes and accessories. Copper plumbing requires higher-skilled specialists to complete the project because copper pipes are joined by using specific techniques. On the other hand, connecting PEX pipes and fittings is a relatively simple task to perform.

For the best results, use only the recommended tools for making PEX connections like a PEX crimping tool. Use a PEX cutter to make clean end cuts that will be easier to work with.

Plumbers should consider PEX’s and Copper’s unique qualities when using them in their work. For example, one needs to take into account that PEX expands and contracts more than copper. Therefore, the PEX pipes should not be installed in a tightly stretched manner. Instead, let it be loose-fitting between fasteners. Sometimes, it’s even worth making a loop from the PEX pipe. That loop will help to reduce the effect of contraction. It can have another benefit: if you mess up with piping and need a little extra length, you can take some of it from the loop. Remember that since PEX pipe moves as it expands and contracts, you need to drill bigger holes through studs and joists so it could move and use plastic straps instead of metal straps to attach it. Also, make sure to keep PEX pipes indoors away from the direct sunlight because they will degrade in UV light.

Here we assembled a list of some Frequently Asked Questions about Copper and PEX pipes.

Can you mix Copper and PEX pipes in one plumbing system?

Yes. There are several manufacturers that offer various types of plumbing fittings: push-fit, stab-in, and other fittings. One of them is SharkBite. The fitting gets pushed from the pipe. Tiny teeth on the fitting hold the pipe in place. SharkBite’s connector fits with any pipe including PEX and copper pipes. The plumber fits the connector to the pipe they use in his plumbing project.

When installing PEX pipes, do you need to use Red for Hot and Blue for Cold water lines?

PEX supply pipes come in white, red and blue colors. Red and blue colors are provided just for your convenience – to help you keep track of the hot and cold lines. However, supply pipes of all three colors are the same. You can use a white PEX pipe for all your plumbing work if you are not afraid to confuse the lines.

Can copper leach into the water and how to deal with it?

When water stands idle in the pipes for hours (overnight), the copper can leach into the water. To minimize this negative effect, you should clear the pipes before using it for cooking or drinking by running the tap for 30-60 seconds. Never use hot water from the tap for cooking or drinking. Copper will leach into hot water even more quickly. Note that new copper pipes often leach more than old ones that have a coating of minerals from hard water. However, old copper pipes used to be joined with lead-based solder which can contaminate your water with the even worse pollutant.

Will the PEX pipe break if it freezes?

Since PEX can expand and contract better than copper, it is less likely to break than the rigid piping. So, PEX supply pipes will probably withstand freezing. You should still protect the tubing from freezing to improve your chances.

What are some good manufacturers of PEX pipes?

There are many different types and brands of PEX on the market. One of the reputable brands of PEX is Uponor AquaPEX. Their PEX is of high quality and it’s been manufactured in Minnesota for more than 35 years.

Copper Pipes vs PEX Pipes

So, Which Pipes are Better: PEX or Copper?

There are many factors to take into consideration when deciding the answer to this hard question. It often comes down to your personal preference or to the special requirements of the project. Many homeowners grew up in homes that had copper piping, so they feel more comfortable with the copper. Others feel that PEX has advantages that they prefer. For example, PEX is a more reasonably priced material and it creates a quieter plumbing system (because PEX better inhibits sound of water rushing through pipes). Both PEX and copper systems enable plumbers to build and manage plumbing projects of any complexity, provide you with a solution to pinhole and slab leaks, etc.

Both PEX and Copper pipes have their advantages and disadvantages. The choice to pick one over the other would rely on several factors like your budget, climate, and your home’s particular necessities. Reaching out to an expert plumber for help with finding the best arrangement is always a good idea!

Since you are on the website dedicated to tankless water heaters, I want to point out that copper generally works better with high heat systems (like the water heaters). It is more heat resistant and its melting point is much higher compared to the PEX’s point. Also, note that PEX pipes cannot be directly connected to a water heater. First, you need to extend a copper pipe 18 inches from your water heater and then connect the PEX supply to that pipe.

Still, PEX is a wonderful material with many benefits that revolutionized the plumbing industry. Also, keep in mind that you can mix Copper and PEX pipes with various fittings and manifolds for flexibility and versatility in any projects. So, you could have the best of both worlds!

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