Examining Polyurea Concrete Coatings
Webfoot Concrete Coatings has completed 1,000+ concrete surface coating projects. We have tried many of the products on the market that claim to provide long-term solutions to damaged concrete flooring.
At first, we experimented with epoxy. Epoxy’s tendency to easily peel, chip, and have a lifespan of only 3-5 years fell short of our expectations for protecting our customers’ hard-working surfaces.
Now, we’re committed to a unique pure polyurea coating system that meets our standards for durability, ease, and quick installation. Before this decision, we invested time in researching and exploring the possibilities, benefits, and real-world performance of polyurea. We’re sharing what we learned so that you can understand what makes a polyurea garage floor coating a high-quality, high-performance coating.
Polyurea is a subgroup of polyurethane, and a 2-part compound (like epoxy). Polyurea is the result of combining two basic chemical ingredients, known as “A” and “B” or “red” and “blue.” Ingredient “A,” or “red,” is always an isocyanate. An isocyanate is a group of atoms that determine a chemical reaction unique to polyurethanes. However, the isocyanate group can be aromatic or aliphatic in nature, which is manipulated for different long-term benefits. Ingredient “B” or “blue” is a resin blend, which can be a variety of property enhancers that are determined by the intended use, the wanted cost per square foot, and the targeted performance of the coating.
Famously, polyurea coatings are valued because they can be installed quickly and cured to an incredible level of hardness. They are also incredibly long-lasting because they form a chemical bond with the concrete. Because of their strength and extremely fast cure rate, they require the expertise of professional installation and use of professional-grade equipment. As a result of the possibilities of polyurea’s two-ingredient combination, there are a lot of differences amongst marketed polyurea products. These differences can impact the performance of the coating, such as polyurea polyaspartic coatings being less durable than pure polyurea coatings (see “Advantages of Polyurea” section below).
It’s important to be informed about the many types of polyurea products on the market before choosing a concrete coating contractor. The product your hired contractor uses will impact the benefits you can expect from your new concrete coating.
Advantages of Polyurea
The advantages of polyurea are dependent on the variety, or purity, of the polyurea product. Different products have very different physical properties and life spans. Also, many companies market “polyurea concrete coatings” that aren’t pure polyurea, but only contain 51% polyurea or more. Variations in polyurea products include, but are not limited to, Polyaspartics, Aliphatic Polyurea, and Aromatic Polyurea. The best advantages of polyurea come from a layered pure polyurea system combining these products.
All polyaspartics are a polyurea, but not all polyureas are polyaspartic. A polyaspartic is a polyurea with a slowed-down cure rate. The purpose of this is to allow the coating to be applied over a longer time frame and in a more traditional manner. Polyaspartic mixtures function well for a topcoat application, but there are limitations when used as a basecoat.
Polyaspartics applied directly to raw concrete (as a basecoat) have several barriers to overcome before forming a strong, long-term bond to the concrete. They cure too quickly to absorb into the pores of the concrete before fully curing. With a polyaspartic product the viscosity, or thickness, climbs rapidly from the moment it’s mixed. As the viscosity climbs, the wetting ability of the product, or the ability for it to bond with a solid surface, is reduced. So, it’s less able to deeply penetrate the concrete. Because of this, polyaspartics can only form a surface bond with concrete. Over time, a surface bond will fail because of the natural cracking of the concrete, which will force through breaking the cap, or top layer of the concrete. The cap is going to be the weakest link in the concrete and even with an aggressive grind, or industrial grade floor preparation, there’s a risk that the coating will shrink and fracture the surface.
The benefit of a polyaspartic basecoat is the lower price point than a pure aromatic polyurea basecoat. The disadvantage is that purity impacts the efficacy of polyurea, and a mixture does not have the strength and durability that makes pure polyurea concrete coatings desirable. As a result, a polyaspartic base coat does not have the same long-term strength and adhesion as a pure polyurea. It may be the right choice based on budget constraints, but there is an increased risk of cracking and delamination when used as a basecoat.
As mentioned earlier, element “A” of the “A-B” composition of polyurea is an isocyanate that can either be aliphatic or aromatic. The variation in this isocyanate impacts the UV stability of the polyurea, and also the cost. Aromatic systems are not light-stable, despite being durable and long-performing in all other ways. In sunlight, the coating’s color will fade, but the coating won’t deteriorate in the way a polyurea polyaspartic would. Because of this light-sensitivity, aromatic polyurea is not a quality choice as a topcoat, but functions as a strong and reliable basecoat.
The application of an aromatic polyurea basecoat requires precision to have the best long-term results. For optimum adhesion, installers will use seasonal blends to adjust the curing time in consideration of temperatures. Basecoats are a 1:2 ratio of A-B, and choosing a blend determines the time available to apply the basecoat after mixing. Getting this mixture and timing correct is essential to avoid mistakes that will result in peeling and cracking.
In contrast, aliphatic systems are light-stable, which means they don’t change color when exposed to light. They also have a high-gloss finish that adds a valuable aesthetic improvement to your space. As a result, they are a great choice for topcoat applications.
Like aromatic polyureas, there is a correct and careful prep and application process. Aliphatic polyureas are mixed at a 1:1 ratio of A-B and at a low speed using a variable speed cordless drill. Mixing at a low speed is essential to avoid air bubbles in the mixture. There are also different blends based on curing time, but utilizing an extreme-heat mixture means the topcoat has an extended pot-life or time before it begins to harden. The topcoat is always applied after the basecoat has been hardened. Other necessary preparation required includes scraping and thoroughly cleaning the basecoat before application.
Pure Polyurea (Aromatic Basecoat & Polyaspartic Aliphatic Topcoat)
A pure polyurea concrete coating composed of an aromatic polyurea as a basecoat and a polyaspartic aliphatic polyurea as a topcoat is high-cost, but high-performance. This type of coating utilizes the hardworking benefits of the aromatic polyurea basecoat, the UV stability and high-gloss aesthetic of aliphatic polyurea, and the slowed curing rate and longer pot-life of a polyaspartic.
Pure polyurea concrete coatings in comparison to epoxy are known to be 4x stronger and 10x more flexible, meaning they won’t chip, crack, or peel under heavy use or in high temperatures. The durability and efficiency of polyurea coatings are due to a fast curing process and the penetrating chemical bond they form with the concrete.
Addressing the bonding difference between epoxies and polyureas, V-seal refers to all coating products as seals. They differentiate the sealing products as penetrating and topical. Polyurea forms a penetrating seal: the coating actually bonds at a molecular level (or crystalizes) to the layer below it – this is the strongest seal possible. Epoxy forms a topical seal: more in alignment with a mechanical seal, or just a membrane adhered to a surface. This is why epoxy chips more quickly and easily than polyurea systems. Long-term, chemical bonds are much stronger than their mechanical sealing counterparts.
The adhesion of polyurea can be tested using a tool called an elcometer, which measures the amount of force needed to delaminate a coating, measuring by pounds per square inch of force. The industry standard for delamination is 500 PSI, but pure polyurea coatings outlast this level of force at 1350 PSI, and typically the concrete breaks before the coatings delaminate, as shown in this Penntek Adhesion Test video. As a result, pure polyurea coatings can be completed in one-day and will last longer than other products.
More About Polyurea Concrete Coatings
Problems with Polyurea Floor Coatings
Webfoot’s product is a pure (100%) polyurea concrete coating that we get directly from the manufacturer, Penntek Industrial Coatings. As a pure polyurea, it differs from competitors who offer polyaspartics and other watered-down polyurea blends. Our pure polyurea is the strongest and most durable form of polyurea. Webfoot is Addressing 7 Problems with Polyurea Floor Coatings so you can feel confident when you choose our multi-layered pure polyurea system.
Polyurea Garage Floor Coatings
In comparison to epoxy systems, there are many reasons that polyurea comes out on top. Explore the comparison of Garage Floor Epoxy vs. Polyurea Garage Floor Coatings to understand what makes polyurea the right choice for your floor.
Polyurea Floor Coating Installation
Professional concrete coatings deliver professional results. We’re supporters of a good DIY project, but when it comes to concrete coatings we make it look easy because we’ve mastered the art. We’ll resurface your floor following a 5-part process: grinding, mending, basecoat application, chip system broadcasting (optional), and topcoat application. And we’ll do it all in one-day.
Polyurea Concrete Coating Cost
Polyurea concrete coatings are a great choice if you are willing to invest more money upfront for a type of coating that will last long-term. The overall total cost of your project will vary based on the 5 Cost Factors of a Concrete Coating Project.
With our free consultation, a Coating Specialist will evaluate your surfaces, explore color and texture samples, and give you a clear written estimate. Contact us to schedule today.
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