Do you need to seal concrete before epoxy?

Epoxy is a popular solution for protecting and repairing concrete surfaces. It’s also often used to enhance concrete flooring.

Homeowners use it to protect driveways from oil stains, repair cracks on garage floors, and add decorative flair to their basements.

Businesses use epoxy floor coating systems because they’re extremely durable, easy to clean, and resistant to heavy traffic. Epoxies are applied in layers that have high abrasion resistance and create a strong bond with the concrete.

Prepping the concrete properly is important when applying an epoxy coating or another type of sealers, such as an acrylic or polyurethane coating system.

This process varies depending on whether you’re dealing with new or old concrete, whether it has been previously coated, and what type of condition the surface is in currently.

Should I seal concrete before epoxy?

Do you need to seal concrete before epoxy? The answer is yes! Concrete sealer is one of the most important steps in a successful epoxy application.

Sealing concrete should always be done before applying a fresh coat of epoxy, as it helps to enhance adhesion between the epoxy and floor, prevent moisture from rising up through the substrate, and provides an extra layer of protection against staining.

Is sealing concrete necessary for epoxy? Yes!

For example, if your substrate contains any moisture whatsoever—and most do—the whole batch can flake off in big chunks later on. Not only will you have to redo the installation, but you’ll also waste money on materials that could have been avoided with just a single step: sealing your concrete first.

Why do I need to seal my garage floor? After all that hard work cleaning your garage floor so it’s ready for a new coat of paint or stain, don’t neglect sealing it too.

A good quality penetrating concrete sealer will repel water and oil stains, protecting your surface from damage over time (not to mention keeping it looking nice).

Is waterproofing necessary with epoxy? Waterproofing isn’t necessary for most residential applications because there isn’t enough water pressure pushing down on them.

But if you’re doing something like installing an entire wall system for bathrooms or showers where there’s more pressure behind that water coming at the surface (from pipes), then yes – waterproofing would be better than not doing anything at all.

How do you prepare concrete for epoxy coating?

There are many ways to prepare concrete for epoxy coating, including applying a concrete primer. However, before you can apply primer, there are a couple of steps that must be taken to clean and prep the floor.

Here are the basic steps you’ll need to prepare your concrete for an epoxy coating:

  • Clean the floor with a concrete cleaner.
  • Remove any oil or grease stains from your garage floor by using an oil and grease remover.
  • Repair cracks or damage to your garages, such as crumbling corners or uneven surfaces with a concrete repair product like Bondo Concrete Patch and Repair Kit (link). This will ensure that the epoxy has an even surface to adhere to once it is applied.
  • Apply a concrete etching chemical meant for preparing garage floors for painting or coating. The etcher chemically “bites” into the cement in order to give it some texture so that the epoxy adheres better than it would on smooth cement alone. Once this is done, rinse off all residue with clean water and allow the surface of your garage floor to dry completely prior to applying any type of primer (water-based) or epoxy paint/coating (oil-based).
  • Be sure to use a shop vac equipped with wet/dry vacuum filters in order to remove any standing water from the surface of your garage floor when you have finished rinsing and drying it – don’t let any moisture remain on top of your newly cleaned floor!

Can epoxy be used over concrete sealer?

Yes! You can apply an epoxy coating over a concrete sealer. The epoxy coating is a thin layer, so it will not harm the sealer in any way.

Plus, the purpose of an epoxy floor coating is much different than that of a sealer. When you’re applying an epoxy coating to your concrete, you are doing so for aesthetic purposes rather than protection.

While a sealer does protect your concrete from damage and deterioration, an epoxy coating enhances the appearance of your concrete and gives it that polished glow.

Please note: if you only have a sealant on your garage floor, or if your garage floor has been sealed with anything other than 100% pure acrylic paint (which is rare), then you should remove the existing sealant before applying a fresh coat of 100% pure acrylic paint as part of our DIY Epoxy Floor Kit.

Do you have to prep concrete for epoxy?

The answer is yes. The concrete needs to be clean, dry, and free from contaminants before you apply the epoxy coating.

If the surface isn’t dry or has an oily residue on it, the epoxy won’t adhere properly. If there are any contaminants on the surface, they can cause adhesion issues.

That’s why prep work is key to a successful coating project. Here’s how we do it:

First, we clean and rinse off all of the dirt and oils from the surface using commercial detergents and water blasters (you can also use degreasers).

We don’t just sweep away dust or use a leaf blower – we completely clean it so there’s no dirt or dust remaining.

We then make repairs to any cracks or holes with concrete patching compound and a trowel (for small areas) or concrete resurfacer for larger areas.

We’ll also repair any divots in your driveway with asphalt filler. All of these materials come in several different colors so that your patch matches your existing concrete color as much as possible.

How long does concrete need to cure before epoxy?

The short answer is yes, you do need to seal concrete before epoxy. However, there are certain conditions that must be met before epoxy can be applied.

Most importantly, the concrete needs to cure for a minimum of 28 days with no moisture present. Also, if you’re applying it yourself, temperatures need to remain consistently above 70F throughout the duration of the application and curing process.

This usually takes between 8-and 10 hours depending on how thick your coating is and how many coats you apply.

Do you have to acid wash concrete before epoxy?

No, acid washing is not necessary to prepare your concrete for epoxy. You can use a pressure washer or scrub the floor with a brush to remove residue and dirt.

If you choose to do an acid wash, you might want to follow up with a rinse and neutralizer (a cleaner that will eliminate any residual acid).

How do you prep a garage floor before epoxy?

After you repair your concrete garage floor, you need to prep the surface for painting or coating. Accomplish this by cleaning and drying the surface.

To ensure proper bonding of paint or coatings, concrete must be free of dirt, grease, oil, and other materials that may interfere with adhesion. The best way to prep your garage floor is with a pressure washer.

Use a degreaser if needed to remove any heavy stains. If you don’t have access to a pressure washer, you can use an acid-based cleaner instead. After using either method, let the floor dry thoroughly before starting the next step!

Do I need to grind my garage floor before epoxy?

You can grind a concrete floor to remove layers of paint or epoxy, or to roughen smooth surfaces so that a coating will adhere better.

You can also grind to create a pattern for example, if you want your floor to look like stone tiles. Grinding, or scarifying, concrete is a good way to prepare concrete surfaces for applying sealers or coatings.

Grinding is also a good way to remove glues and mastics from the surface.


So in a nutshell, the answer is yes… but you might not need to. The levels of humidity and moisture, the type of epoxy being used and the quality of your concrete can all be factors that determine whether or not you need to seal concrete before applying an epoxy coating.

The best thing to do is test your concrete with moisture-detecting equipment, talk with a representative from the company you’re purchasing EpoxyMaster from, and/or consult experts at a paint store as well as friends who have done similar projects.

In general, we recommend sealing if there are any doubts about how much moisture is present in your concrete. You can find more information about other potential problems by watching our video on things to avoid when applying epoxy.

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Martin Flood

Martin Flood has been working in the construction industry for over 20 years as a general contractor with expertise in remodeling projects that are large or small. He has furthered his career by specializing in epoxy resin flooring, providing excellent service to both commercial and residential clients. Martin’s experience enables him to offer professional advice on how to choose the right type of project based on your needs and budget.

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