Nothing takes quite the beating in an industrial or commercial facility like the flooring. Durability, abrasion resistance and traction are common needs for any hard working operation. The flooring has to be able to withstand both pedestrian traffic as well as traffic from forklifts, dollies, and other types of equipment. Then there are the specific needs, such as moisture vapor control; resistance to thermal shock and/or pathogens, such as might be required in an R&D laboratory or a food processing plant; electrostatic dissipative (ESD) flooring can be essential for facilities with sensitive electronics; concrete floor coatings with conductive properties are often mandated where explosion hazards exist.
Epoxies and other resinous flooring finishes are the most frequently used in a wide spectrum of industrial, commercial and institutional locations for a variety of reasons. Though each has its specific features and benefits and will work best in different settings, the decision is ultimately made based on the system performance.
Each of these systems are made up of one or more types of epoxy and other resin-based coatings, applied in multiple layers as primers, base coats, and topcoats.
The short answer is “yes,” and the difference is quite substantial.
Epoxy is a class of thermosetting polymer used primarily in adhesives and coatings, due to its toughness and adhesive properties. Epoxies begin as liquids and get changed into solids, thanks to an amazing chemical reaction.
Epoxy coatings consists of two components: 1) an epoxy resin, and 2) a polyamine hardener. When mixed together in the correct ratio, the two liquids begin chemically transforming, creating tightly cross-linked molecular structures that form a non-porous solid. This process is known as “curing”.
After the resin and the hardener are mixed together, the newly blended epoxy coating has what is called a “pot life.” This means it will stay fluid enough to work with for a fixed period of time under specific temperature conditions. In the case of epoxy floor finishes, the manufacturer’s data sheets may list a pot life of 20 to 30 minutes at 70° F, after which time, the blended material is likely to begin curing, that is, reacting chemically to form a hard solid, and an no longer be spread or applied.
Like other coatings, epoxy is characterized by the volume of its solids content in relationship to its volatiles, i.e., water, solvents and other diluents. In practical terms, the solids content is the amount of coating product that remains on the floor after it fully cures. This is often represented as a percentage. So 100% solids epoxy means that 100% of the product remains on the floor after cure, whereas 50% solids epoxy means that only 50% will remain on the floor as a cured film, while the rest will evaporate.
The application of epoxy and resinous coatings is measured in wet film thickness (WFT, the thickness of the layer when first applied) vs. dry film thickness (DFT, the thickness of the layer once it has cured). If the product is a 100% solids epoxy, the wet film thickness and dry film thickness will be the same. If the product is less than 100% solids, then the dry film thickness will be equal to the solids percentage multiplied by the wet film thickness. The unit of measurement used in the coatings industry the United States is the “mil”, which is equivalent to 1/1000 of an inch.
As an example: With a 100% solids coating, if the WFT is 10 mils, the DFT will also be 10 mils. However, if a 50% solids coating material gets applied at the WFT is 10 mils, the DFT will be only 5 mils.
The variations in percentages occur because the carrier agents—the water and solvents in the product—evaporate during the curing process.
Today, 100% solids is the standard for industrial-grade epoxy floor coatings. When well-formulated, manufactured and installed, they can furnish outstanding performance and value.
Depending on the product, the word “paint” may be a complete misnomer. Paint is typically considered to be a single-component material that dries as a result of the carrier or diluent – water, solvent or a combination of both — evaporating. What remains is a film capable of providing light duty, shorter term protection to a variety of surfaces. Some products called epoxy paint actually have no epoxy in them whatsoever; others have a small amount of epoxy content blended with latex wall paint.
So, why are these products called “epoxy paint”? Homeowner DIYers knew of epoxy as “some kind of topcoat” for garage and basement floors and began using the terms paint, epoxy, and epoxy paint somewhat interchangeably. At that point, marketers of the residential-duty finishes took the path of least resistance and began describing their products in their customers’ vernacular, that is, as “epoxy paint.”
A single component paint finish cannot begin to approach the level of durability or performance of a true, dual component epoxy coating system. Apart from its actual composition, note again that one component epoxy paints simply dry, rather than chemically cure.
This difference in terminology is very telling.
“Drying” simply refers to the fact that the moisture in something evaporates. In the case of paint, a blend of pigments and light duty resin is deposited on the surface after evaporation. The film offers minimal, short term protection for vertical and non-trafficked horizontal surfaces. Dried paint cannot provide suitable concrete protection for commercial, industrial or institutional facility floors.
“Curing,” on the other hand, refers to the process that occurs when the epoxy resin and epoxy hardener are properly mixed, enabling the start of the transformative chemical reaction. An entirely new substance is created during the process, one that is tightly, chemically cross-linked at the molecular level. This give cured industrial-grade epoxy coatings the impervious surface and incredible performance characteristics needed in heavy duty, high traffic settings.
Urethanes, also known as polyurethanes, come in many varieties. Some are modified with oil (OMU) and are primarily used on wood substrates. Other urethanes are emulsions mixed with water that evaporates, leaving a lighter duty film on the surface. Higher performance urethanes include dual component products that cure with the help of a hardener, as well as another type called Moisture Cure Urethane (MC or MCU), which cures with the help of moisture in the air.
The latter two high performance urethane families are used by industrial concrete floor coating manufacturers to further enhance epoxy floor system characteristics. While 2-component and MC urethanes can make great topcoats, they generally do not adhere well directly to concrete and are nearly always applied over an epoxy primer or basecoat. As topcoats, high performance, aliphatic urethanes offer:
• Enhanced durability and abrasion resistance
• Excellent resistance to many solvents and chemicals
• UV resistance and non-yellowing color stability over time
Today’s ultra high solids high performance urethanes are typically applied at a nominal thickness of 2.5 – 3.0 mils DFT. In other words, they are very thin film coatings that provide outstanding benefits.
One of the more recent innovations in industrial coatings, dual component polyaspartic coatings are a distant cousin of polyurethanes. Used in flooring systems, they offer some exciting benefits, including a beautiful high gloss finish, good chemical and abrasion resistance, non-yellowing color stability and UV resistance, plus the impressive ability to achieve full cure in under 2 hours, compared to the 24 – 72 hours required of many epoxies.
This latter benefit, however, comes with a drawback: A very short pot life. For the inexperienced installer, polyaspartics can be extremely difficult to handle. Yet contractors accustomed to the product’s fast-paced installation process swear by it and refuse to go back to slower curing systems.
Mil for mil, the cost of polyaspartic coatings materials do tend to be higher than traditional epoxies and urethanes. However, this can sometimes be offset by lower labor costs, since the application of multiple coats of polyaspartic can often take place in a single day, avoiding the need for a travelling installation crew to overnight in a hotel. And for ‘round the clock mission critical operations that cannot afford to cordon off parts of their facility for more than a few hours, polyaspartic industrial floor coatings can be the ideal solution.
It is probably fair to say that any product labeled as a “floor paint” can be crossed off the list of possibilities. With or without a dash of epoxy, these light duty finishes are simply not suitable for an industrial or commercial facility.
In contrast, high performance concrete flooring systems comprised of dual component, 100% solids epoxy, epoxy with urethane and/or polyaspartic coatings can all be good options. Each can provide excellent performance, depending on your facility and specific site conditions.
Your resinous flooring manufacturer, along with their technical representatives and installation partners are available to discuss your facility needs. Be sure to communicate your specific chemical resistance needs, forklift loads and traffic patterns.
With their training, knowledge and experience, these pros can review your requirements, along with your budget, and help you get the best facility flooring value.