The formulations of polyurethane (PUR) and epoxy flooring systems make each better suited for different environments, and not understanding the differences can lead to dire consequences, according to resin flooring specialist Flowcrete Group (Sandbach, United Kingdom).
According to the specialist, which recently issued a paper1 on the topic, knowing when to apply the right floor is vital not only for contractors but also for project and facility managers. They explain that each system has differing properties suited to particular uses. As such, choosing the wrong solution can lead to costly repairs or even complete floor failure down the line.
Exploring the Molecular Makeup
Some similarities do exist between epoxy and PUR flooring, since both are two-component systems involving a resin and hardener. When brought together, these two components undergo a process of stoichiometric curing to form a solid layer. In both cases, this results in a seamless, impervious coating that can be applied quickly in large quantities, the specialist explains. However, the differing materials that make up each coating lead to distinct applications.
The main difference between the two types of materials is in the molecular structure, which affects how each fuses together during the curing process. While there are multiple types of components that can be used to slightly vary the end result, the specialist says PURs effectively have a higher cross-linked density than epoxies, making them the harder wearing of the two.
Because of this, PUR systems have long been associated with offering strength, durability, and resilience when faced with a variety of testing conditions. These can include heavy footfall, physical impacts, extreme temperatures, and corrosive chemicals. PUR systems are therefore very well suited to industrial facilities, where the floor is likely to face a long list of heavy use challenges each day.
Tough Polyurethane Applications
One drawback to epoxies is that they are much more rigid in terms of structure and cannot tolerate intense heat as well as PUR coatings. For example, some epoxy coatings can resist heat at temperatures up to 65 °C, the specialist explains, whereas PUR systems are available that can tolerate 120 °C.
The superior chemical resistance of PUR floors has made them popular in the food and beverage industry, where corrosive acids and by-products are found in large quantities. This means that floors are required that can stand up to chemical attack from organic acids as well as sugar, malt, caustic, and powerful cleaning agents.
When dealing with PUR flooring, the specialist says it is important to understand the different types. For example, there are full PUR “liquid vinyl” floors, which can create soft surfaces underfoot due to the PUR’s elastic nature. More common are PUR deck coatings used for car parks and PUR concrete systems, which the specialist says are the most failure-resistant type of resin flooring available.
PUR concrete is often found in challenging industrial facilities, as it can withstand punishing impacts, extreme temperatures, heavy loads, harsh chemicals, and more. The PUR concrete can also be customized with anti-slip aggregates, anti-bacterial additives, and is highly adept at dealing with rising moisture. However, the PUR concrete is usually not color stable unless it has an aliphatic coating.
Epoxies Offer Aesthetic Benefits
What PUR systems give in durability is often taken away in versatility and aesthetics, according to the specialist. If those properties are desired, many epoxies can be adapted for numerous environments and are available in a much wider range of colors, styles, effects, and decorative options than PUR.
Unless there is a specific challenge or requirement for a PUR, there will more than likely be an epoxy floor that is up to the task at hand, and which can do so in bright and glossy tones, glittering light-reflective surfaces, or multi-toned swirling shades, according to the specialist.
In turn, this gives designers the creativity to install unique floors that convey an interior design scheme. This is a particularly good way to represent a brand identity, specific aesthetic, or to infuse the environment with a desired vibe.
This has made epoxies a popular floor for large-scale commercial venues, such as shopping centers and airports, as well as in less heavy-duty industrial spaces or for customer-facing processing zones that must look good on top of being functional.
PUR systems also tend to be thicker and heavier than epoxies when applied. While that thickness is great for absorbing impacts and thermal shock, epoxies can offer a thinner and lighter option if weight and space is an issue.
“In summary, it’s not so much a case of which one is better, as it’s really about which one is better for the building in question,” the specialist writes, adding that it has representatives available to assist if potential users have further questions.
Source: Flowcrete Group, www.flowcrete.com.
1 “PU vs Epoxy — What’s the Reason for Different Resins?,” Flowcrete News, Dec. 6, 2018, https://www.flowcretesa.co.za/our-news/latest-news/pu-vs-epoxy-what-s-the-reason-for-different-resins/ (Jan. 17, 2019).