Polyurethane (PU) and epoxy are the two most commonly used resin-based systems for industrial flooring installations.
While both are resins, PU and epoxy floors should not be considered as the same thing. Admittedly they do share similarities, such as being two-component systems (a resin and a hardener) that, when brought together, undergo a process of stoichiometric curing to form a solid layer.
But there are fundamental differences in terms of performance, which determine which system one should specify to ensure it is fit for the purpose.
What is the difference?
The main difference between PU and epoxy is in the molecular structure, which affects how it fuses together during the curing process. Whilst both flooring systems produce a hygienic, durable, smooth and seamless floor, epoxy flooring is generally harder, thus more resilient in high- and heavy-traffic conditions; whereas PU flooring is more flexible or “elastic” than epoxy floors, offering superior scratch, abrasion and impact resistance.
Both types of flooring are sensitive to moisture, but PU coatings and self-levelling materials are much more sensitive to moisture presence than epoxy flooring.
In general, PU flooring materials cure faster than epoxy flooring materials and have a shorter pot life. Nevertheless, both types of flooring require experienced, professional flooring applicators.
PU flooring materials can be slightly more expensive than epoxy floor coverings, but it is important to understand that the price is not always the only factor – and more thought should be put into considering the right kind of material for the facility and/or intended purpose.
Both options provide a chemically resistant surface. Epoxy flooring systems are best suited for chemical handling and processing industries such as battery manufacturing.
PU flooring is the better option for food and beverage processing plants and food preparation areas, such as commercial and institutional kitchens. It is especially well suited in food industries that deal with dairy, milk and beverage production – exposing the floor to lactic acids and other fruit acids.
It should be noted that epoxies can yellow when exposed to direct sunlight and should not be installed externally or adjacent to large glass shopfronts. For applications exposed to significant or direct sunlight, the application of an ultraviolet (UV)-resistant PU sealer may minimise yellowing and discolouration due to UV exposure.
PU flooring delivers either a matt or gloss finish. Epoxies can be very easily adapted for a wide variety of environments and are available in a much wider range of colours, styles, effects and decorative options.
The flexibility of PU floor coatings allows it to act as a waterproofing layer to prevent concrete (substrate) cracks moving through the coating and appearing on the surface in areas such as multi-storey carparks. With an operating temperature range of approximately -15°C to +120°C, a PU flooring system is ideal for areas where thermal shock is expected, such as bakeries with heat from ovens, commercial refrigeration facilities and areas that are steam-cleaned, such as breweries and abattoirs.
Epoxy flooring coatings are harder, providing higher durability and compressive strength. It is well suited for areas that experience heavy traffic and loads like the use of forklifts, including most heavy-duty industries such as machinery manufacturing, warehouses, logistics and general manufacturing. This flooring system is the preferred choice if it will be potentially exposed to battery acid.
Fit for purpose
Using the correct system to get the surface finish you want is critical to ensure that you meet your client’s expectations for the application. The right solution requires careful consideration of the requirements of the application area to ensure that the final floor covering is neither over- nor under-engineered for the required performance.
With such a variety of different options of both epoxy and polyurethane flooring systems available, factors such as chemical exposure, anticipated traffic over the surface and the service and operating conditions determine the specific product selection and the installation thickness of the compound. Speak to a reputable manufacturer for assistance with the specifications.
Issue: Understanding the performance differences between polyurethane and epoxy flooring.
Solution: Unpacking how the two options differ and which is best suited for specific applications to ensure fit-for-purpose specifications.
Full acknowledgement and thanks go to FlowcreteSA and TAL for the information in this article.