Uponor vs. Viega: 8 Important Facts to Help you Choose

Uponor vs. Viega choosing guide

Construction or renovation activities often come with a timeframe. As with modern materials coming into operation, the Polyethylene cross-linked tubing, also known as PEX, is a great addition. 

It is inexpensive, versatile, and even comes with easy installation styles. You don’t need to go the traditional soldering route to get your plumbing needs done. Not just plumbing, it’s got other uses, like usage for fire sprinklers, radiant floor heating, etc. 

The PEX plumbing systems are available in different kinds (PEX-a, PEX-b, or PEX-c).

There are over 20 different PEX types in the market, but the two popular types come from the Uponor (Wirsbo, AquaPEX, and ProPEX) and Viega brands (PureFlow, ProPress, and ViegaPEX). 

The Uponor system uses the PEX-a tubing for plumbing needs which comes with more uses and flexible options. The fitting system for Uponor uses expansion. The Viega PEX system instead uses the PEX-b tubing (although a few from the system uses the PEX-a) with a pressed ring to fasten the PEX to your fittings. 

Choosing between Uponor or Viega could be challenging, particularly with the different use you may need them for. 

Let’s go through some facts that you should consider before selecting between them. 


When it comes to installing fittings, Uponor and Viega have different methods. Uponor, especially AquaPEX, uses the cold expansion route for its fittings, with additional rings to support the PEX. 

The steps involved can be summarized below:

  • Cut up the tube
  • Slide the ring on top of the PEX
  • Expand the PEX
  • Insert the fitting
  • Hold it in place until the PEX contracts on it.

Contraction time varies depending on the size of the PEX tube and weather conditions. 

The Viega system uses a few steps for installation. Since the fittings come preinstalled with the press sleeves, all you need to do is insert the fittings and press them together. 

Time Constraints

The time needed to get the Uponor PEX in place varies greatly, which could be disappointing for contractors who may want a time frame. Even if it’s your private building, timing is key. 

As stated, the Uponor PEX system depends on both the weather and the size of the PEX tube to get in place. You’ll still need additional time for the required pressure tests. 

The time needed to get the Viega system in place is fixed and can be done in minutes. You don’t need to wait longer before adding time for pressure tests. There’s no expansion required here, so you can get the pressure tests done quickly. 

Room for Error?

A significant fact in any plumbing work to be done is to ensure there is little error. 

The Uponor system requires a human touch since you need to keep the fittings in place while the PEX contracts on it. There could be an error since your hands could make a stretch mark on the pipings to a certain degree. 

Don’t forget the human factor where overexpansion could occur, leading to the risk of tears and leaks. 

The Viega system uses a predetermined method to secure the PEX to the fastings. There is no need for expansion, with more styles to help installers detect any potential tear risks.


Getting Uponor tools in the market is cheaper than that of the Viega system. There are different options when considering the proper tools, especially manual ones.

You could get various manual tools for less than $50 on Amazon. The manual tools costs around $150+.

The Viega system, on the other hand, is expensive. Since they come with additional technology to avoid cold expansion, you could get the tools on Amazon from $200 and above. Generally, Pex-b tubings are more expensive than PEX-a tubings. 


There are many things you can use Uponor for, compared to Viega which makes it pretty flexibility. 

Uponor (PEX-a) comes with little to no coil memory and even allows the repairer to use heat to repair areas that need mending. 

Besides, you can reshape the Uponor PEX to any style, but it will still return to the standard shape. Just use a connection (coil) inside, and it will form a bond. 

This property allows it to be used in other areas aside from the plumbing. PEX-a can also be used in fire sprinklers system too.

The Viega system comes with less flexibility. Its fittings come preinstalled with tools to fit just the plumbing aspect.


Many people prefer to use Uponor fitting system because it is stronger than the PEX-b. Contrary to what some resources online say, the cold expansion has been described as the best method. 

Aside from human factors that could result in over-expansion, the pipe fits nicely and firmly to the fitting for maximal results.  

While Unogor fittings can be expanded, the Viega system cannot be expanded, and you should not attempt to expand the ends of a Viega pipe. 


High performance is one factor we all want to see as an end result when carrying out building works. 

The PEX-a (Unogor system) has proven to be the best because it passes all the international tests, which are set for high performance. 

Viega tubings have low resistance compared to the Unogor system, and plumbers who have attempted to expand it found out the tubes turn out kinked, which is not suitable for installation. 

Manufacturing Materials

PEX-b is generally considered a less reliable material when compared to PEX-a. It comes with materials and components which could compromise the system and display many defects in its fittings. 

PEX-a materials are made from the best anti-freeze and anti-kink resistance materials. So you can have a little room for error (not too much, though), and the anti-kink technology will protect against leaks. 

In addition, the diameter of both PEX tubes differs. The diameter for PEX-b materials is pretty minor than PEX-a (Uponor), which means less water can pass through the Viega system than the Uponor tubes. 

Uponor’s internal diameter is 12% higher than that of Viega’s. This explains why it has more extensive use in fire sprinkler systems. 

Final Thoughts 

Uponor and Viega have different users and applications. 

Ensure you are aware of the distinguishing factors, strengths, and limitations of each before deciding on which tool to go for. 

Since priorities differ, we cannot recommend one as the best. However, with this insight into their difference, you have what you need to select the best tools for your need. 


Uponor Propex vs. Viega Pureflow

Using pex tubing

Uponor vs. viega propex expansion vs pureflow

Uponor pex fittings viega faster install

Which is better: pex a or pex b?

Find out why uponor pex is awesome

Viega vs uponor pex which is better?

Pex a vs. pex b