Lesson 3: When it comes to PEX vs. copper, which pipe scores the highest?

Students in the U.S. and Canada are officially back in the classroom for the school year. But just because we’re no longer kids, doesn’t mean we can’t learn a little, too! During September, we’ll be going back to school with PEX. This week is lesson three. You can also read Lesson 1 and Lesson 2 to get you up to speed.


Let’s get started.


Whether you’re repiping a single-family home or plumbing a new commercial building, the biggest question is what type of plumbing system to choose: PEX or copper? Today, we’ll take the piping through three tests based on flexibility, durability and sustainability to see which pipe is best for plumbing.


Exam 1: Flexibility

PEX offers the tightest bend radius of any plumbing product on the market — as little as 3½" for ½" tubing. This eliminates the need for fittings and connections with each change of direction, and fewer fittings reduce your liability for leaks and problems.


Copper is a rigid metal system and therefore provides no flexibility. 

Exam 2: Durability

Because Uponor PEX can expand up to three times its size before returning to its original shape, it’s highly resistant to damage from frozen water in the system. Plus, our ProPEX® connection method uses the shape memory of Uponor PEX tubing to make a strong, reliable and watertight connection. Typically, connections are the weakest point in a plumbing system and where leaks occur the most, but Uponor’s ProPEX technology actually gets stronger over time, making it the most durable PEX connection method on the market. Not to mention, PEX tubing will not pit, scale or corrode.


Copper will corrode overtime and is also susceptible to pinhole leaks caused by harsh water conditions. These tiny leaks can slowly damage a structure before the homeowners or occupants are even aware there’s a problem.

Exam 3: Sustainability

A 2008 life-cycle study* showed PEX requires less energy to produce and has an overall lower carbon footprint compared to copper.


*Source: “Life Cycle Inventory of the Production of Plastic Pipes for Use in Three Piping Applications”, Franklin Associates, 2008.


Copper has no rebuttal. 

Here at Uponor, we genuinely believe in creating better human environments and that often starts with what’s behind the walls. When it comes to flexibility, durability and sustainability, PEX tubing for plumbing systems is best in class. 


If you want to learn more, check out our PEX vs. copper fact sheet here.


Class is dismissed! Meet back here next week for our final lesson.