Epoxy Concrete Sealer

  • June 15, 2020
  • / By Dale Keese
epoxy concrete sealer

Epoxies are essentially a thermosetting polymer coating which also acts like a concrete sealer. This type of concrete sealers form a high-build film on the surface of the concrete and produce a hard finish which is resistant to abrasion and wear. Epoxy sealers are also water repellent.

Our pick for the best epoxy concrete sealer is the Rust-Oleum Epoxy Shield due to its high resistance to contaminants and corrosion. Perfect for garage floors due to its resistance to oil, grease, gas & other spills.

Click here to see our review.
Rust-Oleum EpoxyShield

Epoxy sealers are available in three formulations: 100% solids and water- and solvent-based, which are used in varying thicknesses between 3 mils to more than 10 mils for a single coat. Epoxy concrete sealers are easy to apply and are available in varying VOCs.

Epoxy concrete sealers are available in two varieties, clear or pigmented, that lets you add color to the concrete surface. Most epoxy sealers offer a glossy finish and they are much harder compared to acrylic sealers.

Water-based epoxy sealers offer a clear finish and adhere well with the concrete surface; however, they are nonporous and do not allow the moisture that is trapped inside to escape. Epoxy sealers are ideal for areas where food is prepared and for concrete countertops. Epoxies bond quite well to concrete that is properly prepared and are also sometimes used on old or worn concrete as resurfacing agents and also to repair cracks, pitting, and surface repairs on concrete.

Concrete Counterop

Epoxy sealers containing high to 100% solids are considered the best epoxy formulations and are very thick, hard, and impact-resistant. This thickness helps to fill out the imperfections on the surface of the concrete, fill hairline cracks, and also provide a high-build coating to protect the surface.

Epoxies resist wear due to abrasion and also are resistant to hot tire pickup. Although several epoxy formulas come with UV inhibitors, when exposed to sunlight, they eventually will turn yellow.

  • Concrete countertops
  • Food preparation areas
  • Floors in high-traffic areas
  • Cement-based overlays

Application

Most epoxy sealers are products that consist of two components that must be mixed before application. When you mix the epoxy sealer, you must apply the material immediately, before it starts to set. Epoxy sealers are quite viscous and have high solid content and so they are best applied using a squeegee and then rolled with a lint-free roller.

Generally, epoxy sealers are used indoors because they may turn yellow when exposed to UV rays. A high-gloss clear epoxy sealer is ideal for decorative floors and will not only protect the floor from wear and abrasion but also augment the color and enhance the floor’s design.

Below are the steps for application of epoxy sealer to a concrete floor/surface:

  1. 1
    First using a broom and a dry or wet vacuum cleaner, clean all the dirt and debris from the concrete surface. Using a degreaser and a stiff brush, remove all the grease and oil from the concrete and then using a garden hose, rinse off the degreaser and let the floor dry. 
  2. 2
    The epoxy coating kit usually contains an etching solution. Using this, etch the concrete surface.
  3. 3
    Mix the solution with water and pour it onto the concrete surface and work it with a broom or stiff brush. Using a garden hose, rinse the entire area properly and let the surface dry completely, which can take several days.
  4. 4
    Mix the epoxy, which consists of 2 parts – a hardener and resin that should be mixed just before you start the application. Stir the coating and pour the catalyst while stirring. Stir for 2-3 minutes until both parts are mixed properly. Let the mixture rest for the time recommended by the manufacturer.
  5. 5
    Begin applying the epoxy coating. You have around 2 hours for the entire application. Throughout the application and initial curing, keep the area well ventilated.
  6. 6
    Use a roller to spread the epoxy coating on the concrete surface and use a paintbrush for the edges. Work in 10 feet x 10 feet sections.
  7. 7
    Wait for at least 12 hours before you apply the second coat.
  8. 8
    Allow the surface to dry completely. Do not walk on the floor for at least 24 hours and wait for a few days before parking your vehicle on the concrete floor.

Frequently Asked Questions

What is the difference between epoxy and sealer?

A concrete sealer is suited for outdoor surfaces that are exposed to the elements and can get damaged and break up over time because of the freezing and thawing. Usually, when we speak about concrete sealers, we are referring to a penetrative sealer like a siliconate or silane or an acrylic-resin sealer. Concrete sealers are usually used for patios, driveways and other outdoor concrete surfaces, home basements and indoor surfaces that do not have a lot of traffic.

Usually, epoxies are also considered as a kind of sealer; however, they add several other properties and are usually considered separately. Epoxy coatings form a glossy, high-build, protective film on the surface of the concrete and produce a hard and abrasion-resistant finish that is durable. They can be clear and colored and are generally water repellent.

However, epoxy coatings are different from acrylic sealers as they are non-porous and prevent trapped moisture from escaping. Generally, epoxies are harder compared to acrylic sealers and offer a higher level of adhesion to the concrete surface. When applied, epoxy coatings offer excellent abrasion and wear resistance and also protect the concrete from chemical spills. Because of their inherent strength epoxies are used in retail stores, industrial warehouses, airports, etc. that experience a high level of traffic.

Like acrylic sealers, epoxies are also surface-level concrete sealers which are ideal for in-depth applications that require a higher level of protection, while acrylic sealers are better for lighter and residential applications.

Do I need to seal concrete before epoxy?

Usually, epoxy coatings are applied to concrete surfaces to provide a smooth, high-performance and durable surface that can withstand heavy loads and last for several years. Epoxies require a slightly porous and clean surface to adhere properly. Epoxy coatings may not bond to polished or sealed concrete and so there is no need to seal the concrete surface before applying an epoxy coating.

Can you epoxy over sealed concrete?

If a sealer has been used on a concrete surface, you can use epoxy over the concrete because it will not adhere to the surface properly. You must test the surface for sealer by pouring some water on the surface. If the water beads on the surface instead of soaking in, it has likely been sealed and will not be suitable for epoxy coating. You must remove the old sealer before you attempt to coat it with epoxy.

How much epoxy sealer do I need?

If the concrete surface is perfectly flat, 1 gallon of epoxy coating with 100% solids:

  • At 1 mil thickness will cover around 1,600 sq. ft.
  • At 5 mils thickness will cover around 320 sq. ft.
  • At 10 mils thickness will cover around 160 sq. ft.
  • At 20 mils thickness will cover around 80 sq. ft.

The quantity of epoxy sealer required depends on the condition and porosity of the concrete surface and the temperature and humidity conditions.

How long does epoxy coating last on concrete?

How long an epoxy coating can last on the concrete surface depends on the traffic in the area. For instance, in a residential area with a light foot and vehicular traffic, the epoxy coating can last for up to 30 years; however, in a commercial or industrial area with heavy traffic, the coating may last for around 5 to 10 years or maybe longer.

The life of the epoxy coating also depends on other factors such as:

  • The thickness of the epoxy coating.
  • Strength of the concrete surface.
  • Preparation of the surface.
  • Quality of the topcoat on the epoxy coating.
  • UV resistance of the coating.
  • Maintenance of the concrete floor.

Can epoxy be removed from concrete?

Some of the methods by which epoxy coatings can be removed from concrete surfaces are:

  • Acid Wash: First, soak the concrete floor or surface with water. Make a wash using 12 oz. of muriatic acid with 1 gallon of water. With a scrubbing brush, apply this wash to the epoxy coating and let it soak for around 15 minutes. Sprinkle baking soda on the concrete surface to neutralize the acid. Using a pressure washer, remove the acid wash from the epoxy coating. You may have to repeat the process many times to remove the coating completely.
  • Solvents: You can remove the coating from concrete surfaces using solvent; however, it is quite a time-consuming and labor-intensive process. Using a metal or plastic scraper or a handheld tool with a scraper blade, scrape off as much epoxy coating as possible. Then, apply a generous amount of solvent such as acetone, lacquer or paint thinner to the concrete, working in small areas. The solvent will penetrate the epoxy coating and allow you to continue scraping it easily. Remove the entire epoxy coating and, using a garden hose, wash the concrete surface with water. This will remove the epoxy coating that is remaining on the surface and prepare the surface to reapply a new coat of epoxy. 
  • Grinding: Using a floor grinder can help to remove the epoxy coating more easily. You can either rent or purchase a floor grinding machine. For edges, corners and other stubborn areas, you can make use of a handheld rotary grinder to remove the epoxy properly. Using a dry or wet vacuum cleaner, suck up all the debris. This will let you see if you have finished a particular area before you move to the next.

About the Author

Hey guys, thanks for reading.. hopefully this article can save you some time and trouble with your sealing job. I'm also in the process of making some video walk-throughs for youtube so check back soon! thanks

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