Concrete sealers are chemical substances that are essential for protecting concrete surfaces from staining, water erosion, extreme temperatures, oil, dirt, and other contaminants. They provide a strong layer of permanent or temporary protection to concrete surfaces and floors. Protecting the surfaces from moisture, concrete sealers help improve the durability of concrete and at the same time manage their appearance.
Acrylic Concrete Sealers
Acrylic sealers are the most widely preferred concrete sealers in the concrete industry. Besides being budget-friendly, their application is straight forward and quick. They can be applied soon after the installation of concrete and are known to possess remarkable recoating abilities.
Moreover, some acrylics are ultraviolet resistant. In addition, if you’re looking out for a concrete sealer that functions well against moisture, de-icing salt, and chemical or oil absorption, acrylics is an ideal sealer type. Despite being thinner than other types of concrete sealers, acrylic sealer doesn’t allow anything to slip through the cracks.
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Acrylics can be used both on the exterior and interior concrete surfaces. They play a crucial role in improving the overall color of the concrete regardless of the concrete type- stamped or stained. After applying, acrylics dry in a comparatively shorter time, generally around an hour.
However, one drawback of acrylic sealers is that they’re not very durable. The fact that they’re thin means that they wear away quite fast and thus, you’ll be required to apply chemicals once in a couple of months and recoat soon. Moreover, acrylic sealers often turn yellow after some time unless you opt to use a sealer with non-yellowing chemicals.
In some cases, they might even divide into layers, damaging the smooth concrete surface. In terms of usage, acrylics are best for full depth colored concrete, pattern concrete, exposed aggregate, stencil concrete and style pave concrete coatings. They’re used in exterior surfaces to protect them from water and chloride intrusion.
Acrylics are also frequently used in interior surfaces for protection and to give an aesthetic look by enhancing the color. Since they dry quickly, they’re preferred over others for fast-track projects.
There are two main types of acrylic concrete sealers: water-based concrete acrylics and solvent based concrete sealers are. Let’s study them separately:
Water-Based Acrylic Sealers
These are acrylic sealers suspended in water that have several advantages over the other main type which are solvent-based concrete sealers. Water-based concrete sealers don’t release harmful vapors into the atmosphere, are safer for workers and are cheaper and easier to apply. They’re more durable than solvents and help reduce sealer issues such as bubbling and roller marks.
However, should a problem arise, water-based acrylics are challenging to remove. They don’t function well at temperatures below 50 degrees Fahrenheit and would often freeze in low temperatures. Also, they don’t provide the darkening effect many people prefer.
Solvent Based Acrylic Sealers
This type of acrylic sealers includes those suspended in a solvent. For outdoor applications, solvent-based acrylic sealers perform much better than water-based acrylics, especially in terms of enhancing the color of color. They give the concrete surface a nice, wet look by providing that a darkening effect that some customers prefer.
In case of recoating, solvent based acrylics are much more feasible than water-based ones since they don’t require any extra preparation prior to recoating while water-based acrylics need to be screen sanded before recoating can be applied.
Source: Concrete Decor
Penetrating sealers absorb into the concrete to prevent moisture from entering and at the same time allow vapor to escape from inside the concrete surface. Without changing the appearance of the concrete surface, they provide invisible protection while retaining the natural look of concrete surfaces. Penetrating concrete sealers are flexible enough to be used on a variety of bare concrete surfaces for safeguarding against staining, erosion, ultraviolet rays, weather, and extreme temperatures.
They are highly resistant to intense heat and freezing temperatures, elements that can easily disintegrate concrete surfaces. When it comes to coating frictional surfaces like walkways and driveways, penetrating concrete sealer is preferred over film forming sealers like acrylic or polyurethane. This is because it doesn’t leave that glossy film that increases the slipperiness of the concrete surface.
It also helps to improve the durability of the concrete surfaces at sidewalks, driveways, and patios.
Additionally, penetrating sealers contain an advanced formula that they chemically react with the capillaries of driveways, protecting the surface from moisture penetration, chemicals, and de-icing salt. However, penetrating sealers can only be used for coating exterior concrete surfaces only, not interior ones. Moreover, if the coated concrete surface is exposed to moisture or water before it dries, the surface would start bubbling or foaming.
Source: Concrete Color Systems
The different types of sealers in this category include silane, silicate, and silicone, each of which is used for different purposes. Below are some details about each of them:
Silicate Concrete Sealers
Silicate concrete sealer potentially serves to harden and increase the density of concrete surfaces. It doesn’t alter the look of surfaces, retaining the natural appearance. However, it promises no protection from water erosion.
Silicone Concrete Sealers
Silicone concrete sealer serves as a short-term sealant that offers temporary protection to surfaces. This means that you’ll have to recoat at regular intervals. Hence, they’re usually applied for temporary use such as on concrete walls for protection against graffiti or other vertical concrete surfaces that are exposed to dust and need regular cleaning.
By penetrating deep inside the concrete surface, silicone concrete sealers function incredibly to retain the natural appearance of the concrete surfaces. If protecting the look of the surfaces is a priority, silicone sealers are an excellent choice. However, since they offer no protection from ultraviolet rays, they aren’t a good choice when it comes to surfacing a horizontal surface or any outdoor concrete surface.
Silane Concrete Sealers
Silane concrete sealer involves a thick application and multiple coatings, normally 2 to 3. This helps attain long-lasting protection of up to 8 years. They’re often used in parking garages and exterior vertical surfaces that are built up of concrete bricks and blocks.
On the other hand, owing to multiple thick coatings, silane concrete sealers tend to darken the surfaces, thereby altering their natural appearance. Therefore, they’re used when sturdiness and protection are the main objectives.
Source: Port Aggregates
Polyurethane sealer is almost twice as thick as an acrylic concrete sealer. By forming a sturdy safeguarding film on the surface, it offers stiff protection against erosion and chemicals. It ensures excellent durability and prevents the surface from turning yellow.
Protecting against staining and scuffing, its finish ranges from being slight sheen to a high gloss. Again, polyurethane sealers come in two forms: solvent and water based. Polyurethane sealers are ideal for interior and exterior surfaces that are subject to constant pedestrian and auto traffic such as walkways, amusement parks, shopping malls, and café floors
Polyurethane sealers are abrasion resistant and offer flexibility to resist impacts that weak acrylic sealers cannot withstand. Hence, they function exceptionally well on garage floors.
Source: Concrete Network
Polyurethane sealers are commonly used in high-traffic concrete roads to provide strong resistance to staining and scuffs and applied on concrete countertops. They’re suitable for both interior and exterior concrete and are ideal for decorative concrete. They’re also applied to colored, stamped or exposed-aggregate concrete.
They can potentially function for 4-8 years before recoating is needed. However, they shouldn’t be applied to surfaces with water as they aren’t moisture tolerant until they completely dry up. If they’re exposed to water, a chemical reaction will occur, resulting in foaming and bubbling on the surface.
Plus, they can pose problems for some exterior concrete surfaces such as driveway for they don’t permit the release of moisture vapor from the concrete. Moreover, polyurethane sealers contain high levels of VOC (Volatile organic compounds) that are dangerous to human health and can harm the environment. Therefore, a respirator should be used when applying the sealer.
At the time of recoating, the concrete surface requires sanding to enable a strong grip with the new coating, which is not the case with acrylic sealer. Polyurethane sealers need to be applied in the daytime as they are relatively more sensitive to moisture.
Source: Port Aggregates
In contrast to the application of acrylic sealers, the application of polyurethane sealer demands more care. Instead of using a garden-type pump-up sprayer to apply water-based polyurethanes, use a high-pressure, low volume airless sprayer. This is because water-based polyurethanes don’t reach the pressure levels needed to achieve thin, even spray patterns.
A micro-fiber mop is also a great tool to apply polyurethanes. It allows for a push-and-pull motion to form a thin, even spray pattern.
Epoxy sealers are characterized by a thick protective film on concrete surface, offering a robust, long lasting and abrasion resistant layer. They also function amazingly as a water repellent. Much harder than acrylic concrete sealers, epoxy sealers are an ideal choice for concrete countertops and kitchen surfaces. Epoxy sealers are an ideal option for designing purposes as color pigments can be easily added to them, and they leave behind a glossy surface.
A high-gloss epoxy finish on decorative floors enhances the surface color, bringing the design to life. At the same time, it would protect the floor from damage and foot traffic. Similarly, they can be transformed to be used for garage floors and factory surfaces by adding an anti-slip aggregate to them.
Source: Port Aggregates
Epoxy sealers are widely applied to floors in high-traffic as well as on surfaces used to prepare food. Kitchen countertops are the most common application for epoxies. Additionally, other concrete countertops and cement-based materials also make use of epoxies.
Other applications of epoxies include flake and metallic flooring, industrial uses in schools and hospitals and floor coating that are solvent and abrasion resistant. In industrial and hygiene sites that go through extreme wear and require regular cleaning, epoxies are used in the form of hard wearing, low odor, and chemically resistant coating.
Source: Concrete Color Systems
Since epoxy sealers are highly vulnerable to ultraviolet rays leading causing stains, they’re more often used for interior concrete surfaces. Unlike acrylic and penetrating sealers, they do not offer the best to concrete surfaces for inhaling and exhaling airborne moisture once they dry up. But water-based epoxies bond pretty well with concrete, providing a bright finish.
Polyaspartic sealer, also known as polyaspartic polyurea, was introduced recently as a miraculous new concrete floor coating that offers tremendous features. It serves as a solution to issues pertaining to all other concrete sealers. It can be applied at any temperature, dries or cures in just half an hour and can bear extreme temperatures when cured.
Moreover, it bonds smoothly with any concrete surface and serves outstanding resistance to ultraviolet rays and staining. Let’s examine those benefits in detail: Polyaspartics cure rapidly within 5 to 120 minutes and be safely applied at surface temperatures between -30°F to 140°F.
It has an outstanding wetting ability owing to extremely low viscosity, and a single coat of polyaspartic sealer can have a film build of up to 18 mils. High humidity normally results in bubbling, but polyaspartics offer bubble-free surfaces even at high humidity. They’re created of solids content as high as 100% which ensures no or low VOCs (Volatile organic compounds) at the time of application.
Once cured, polyaspartic coatings can withstand temperatures up to 350°F and are higher abrasion resistant than epoxies or polyurethanes. The finish is crystal clear that can resist stains from heavy items like oils, fats and even red wine.
Source: Concrete Network
Polyaspartic sealers can be used both for exterior and interior concrete, though traction aid must be provided when they’re used externally. They’re commonly used in laboratories, industrial spaces, homes, shopping centers and other sites that require a quick turnaround time.
Source: Concrete Color Systems