How to Remove Sealer From Concrete

As a homeowner, nothing is as frustrating as watching your concrete sealer degrade. Along with impacting the look of the surface, it usually means the protection the sealer provides isn’t as reliable. When a breakdown occurs, you need to remove the sealer from the concrete to refresh the surface or prepare it for a new coat. But figuring out how to remove sealer from concrete correctly isn’t always easy. Fortunately, a few approaches can work well.

When you need to remove sealer from concrete, you can choose either a mechanical or chemical-based option. Sanding, grinding, and blasting can all work well, and power washing may be an option. Otherwise, you may need a solvent-based, caustic, or biochemical stripper.

Which of those strategies is best depends on a few factors, such as the type of sealer in place, its current condition, and whether you prefer to avoid chemicals. If you need to figure out how to remove sealer from concrete, here’s what you need to know.

How to Remove Sealer From Concrete

Can You Remove Sealer from Concrete?

Yes, you can remove sealer from concrete. Precisely how challenging the job is can vary depending on the type of sealer and how deeply it penetrated. However, getting it removed or addressed to the point where you can apply a new coat is almost always possible.

If you’re wondering, “Why would you need to remove a concrete sealer?” the answer is simple. Many types of sealers can break down over time, leaving you with less protection for your concrete surface. Additionally, if improperly applied, adhesion issues or flaking can occur.

When your sealer isn’t in great shape, removing it allows you to correctly prepare the surface for a new coat. After removal, a new sealer is more likely to bond correctly, giving you a better, longer-lasting result.

Additionally, sealers may apply color or alter the look of your concrete. If you prefer a different aesthetic, removing the sealer gives you a fresh surface to work with, making it easier to apply something else that provides you with the appearance you’re after.

How to Remove Sealer from Concrete

Removing sealer from concrete isn’t necessarily difficult, but there are safety considerations you need to take into account. You may be dealing with materials or chemicals that can cause harm if they contact your skin or eyes; some can irritate the lungs.

Before removing the sealer from your concrete, you need to get the right personal protective equipment (PPE). At a minimum, you’ll need gloves, goggles, and a breathing mask. Closed-toed shoes are also a necessity.

For chemical-based approaches, wearing disposable coveralls is a good choice. That ensures your underlying clothing is protected against splashes, and you can throw the coveralls away without worrying about cleaning off the chemicals.

Sometimes, you may need plastic sheeting or tarps to cover nearby plants or other surfaces. That reduces the risk of accidental exposure or contact with the stripper or materials.

Once you have the necessary PPE and other equipment, you can remove the concrete sealer. Which option is best may depend on the type of sealer present and personal preference.

If you’re considering a chemical stripper to remove sealer from concrete and aren’t sure what type of sealer is in place, it’s best to conduct a test before you select a stripper. Pour a small amount of xylene in an inconspicuous spot. Let the xylene sit for 30 seconds, remove the excess, and then rub the area.

If the spot is sticky, you have a solvent-based sealer. If it’s not tacky, you have a water-based sealer. By knowing that, you can make sure that any stripper, you choose to compatible with your sealer type, leading to a better result. You also want to clean the surface of the concrete before going forward with any of the removal options.

1. Sanding

How To Sand Concrete

Set Up the Sander

If you want to sand off the concrete sealer, the easiest option is usually a sanding disc on a buffing machine. It allows you to cover more surface area and lets you stand while you work, which is often more comfortable.

Sand the Sealer Off

Once the sander is set up, you can start removing the sealer. Work on one section at a time, ensuring the sander remains in constant motion. Usually, a sweeping motion works best. Just make sure to overlap the edges of every pass.

Clean and Rinse the Concrete

After sanding off the concrete sealer, you want to sweep the surface to remove debris. Once that’s done, rinse the surface with water to get rid of any dust. Finally, let the concrete fully dry before applying any new sealer.

2. Power Washer

Power Washer

Set Up the Pressure Washer

Sun Joe SPX3000 14.5-Amp Electric High Pressure Washer, Cleans Cars/Fences/Patios, GreenGenerally, a pressure washer can remove concrete sealer that’s starting to experience adhesion issues. Before you work across the main surface, choose an inconspicuous spot as a test area.

Begin with the pressure washer on a low-pressure setting and use a fan tip. Slowly increase the pressure to find the point where the sealer comes off but the concrete beneath remains undamaged. Ideally, you want to use a back-and-forth or circular motion, ensuring you don’t leave the tip stationary for too long.

Pressure Wash the Surface

Once you find the right pressure setting, remove the sealer from the surface in small sections. Continue using the sweeping or circular motion, as keeping the tip stationary increases your risk of damage.

Rinse with Water

After going over the entire surface, use a hose to rinse the concrete surface. That eliminates any debris that wasn’t fully pushed off of the concrete. Once that’s handled, let the concrete completely dry.

Check the Results

While a pressure washer can remove concrete sealer that’s peeling or experiencing adhesion issues, it may not work in all cases. As a result, you want to check your results after the concrete dries. If not all of the sealer is gone, repeat the pressure washing process or try another method to eliminate the rest.

3. Grinding

Remove Concrete Sealer

Prepare the Grinder

Diamond grinders can work well for thick concrete sealer layers or seals that are hard to remove. You’ll want to put the grinder onto your device following the manufacturer’s instructions. Then, start with a test spot to ensure you get proper penetration without digging into the concrete below.

Grind the Surface

After the test, you can start grinding the rest of the concrete surface. Keep the grinder in motion to reduce the chances of deep gouges or an uneven surface. You need to be meticulous as you work, as staying in one spot too long can cause you to grind into the concrete.

Clean and Rinse the Concrete

Once you’re done grinding, sweep the surface to remove debris. Then, rinse the concrete with a hose and let it dry.

4. Blasting

Sandblasting

Gather Materials

Blasting requires several items to make it work. First, you’ll need a sandblasting or soda-blasting unit and an air compressor. Then, you’ll need filtered silica sand or sodium bicarbonate, depending on the blasting you’re doing.

Prepare the Unit

Blasters can have varying designs, so you’ll need to review the manufacturer’s instructions to set it up correctly. Once assembled, begin on the lowest pressure setting, keep the nozzle about 12 inches from the surface, and do a test spot. Increase the pressure slowly until the sealer comes off, leaving the concrete unharmed.

Start Blasting

Once you finish the test spot and have the right settings, you can work across the rest of the surface. Use a sweeping motion to blast off the sealer, working in small sections until the job is complete.

Sweep and Rinse

After removing the sealer, sweep the surface to tackle any debris. Then, rinse the concrete with a hose and let it dry.

5. Solvent-Based Strippers

Solvent-based strippers are the most widely used type of stripper, as they work quickly, and a little goes a long way. The composition of solvent-based strippers can vary, and they may contain methylene-chloride, N-methylpyrrolidone, dibasic esters, toluene, xylene, acetone, or alcohol, for example. Generally, this option works for acrylic, polyurethane, epoxy, polyurea, and polyaspartic sealers.

Review the Directions

Before you use a solvent-based stripper, read the manufacturer’s directions. That will tell how about the application thickness and how long to let it sit.

Apply the Solvent-Based Stripper

Apply the stripper following the directions. Usually, this is easier if you apply it with a stiff-bristled push broom. Allow the stripper to sit based on the manufacturer’s recommendations.

Scrub and Scrape the Surface

After the stripper has sat, use a stiff-bristled broom to scrub the surface. Then, shift to a squeegee to push the stripper off and into a container.

Clean and Rinse the Concrete

Once the sealer is gone, you need to clean and rinse the concrete. Follow the manufacturer’s directions regarding cleaning options and rinsing instructions. Then, let the surface dry.

6. Caustic Strippers

Caustic strippers contain strong alkaline chemicals, and they work well on latex, alkyds, and enamel paints on concrete surfaces. They aren’t ideal for surfaces that are caustic chemical-resistant, such as epoxy, polyurethane, or acrylics.

Read the Instructions

Before you begin, review the manufacturer’s instructions regarding application methods, thickness, and sitting times. What’s best can vary from one product to the next, so make sure you follow the directions closely.

Apply the Caustic Stripper

Apply the caustic stripper to the concrete. Using a push broom can make this easier, so consider going that route. Then, leave the stripper in place for as long as the manufacturer recommends.

Scrub and Scrape the Concrete

Take a stiff-bristled push broom to loosen the sealer. Then, take a squeegee to push it up and off, preferably into a container you can use for safe disposal.

Clean and Rinse the Surface

After removing the stripper, you need to clean and rinse the concrete. Follow the manufacturer’s directions regarding proper cleaning and rinsing methods.

7. Biochemical Strippers

Biochemical strippers are made from plant materials and have a lower environmental impact. They’re a reasonable choice if you need to work in areas where overspray or rinse water may harm nearby landscaping. But they work far more slowly than the alternatives, extending the length of your sealer removal project.

Read the Directions

As with all strippers, you need to read the manufacturer’s instructions to ensure safe and proper use. Review them before you begin, ensuring you understand the right process.

Apply the Biochemical Stripper

Apply the biochemical stripper per the manufacturer’s directions. A push broom can simplify spreading it, so consider going in that direction. After it’s on, let it sit for the amount of time recommended by the manufacturer.

Scrub and Scrape the Surface

Take a push broom and scrub the surface. Then, use a squeegee to scrape the concrete and move the sealer into a suitable container.

Clean and Rinse the Concrete

Follow the manufacturer’s directions to properly clean off any remaining residue. Then, rinse thoroughly before letting the concrete dry.

How to Remove Acrylic Sealer from Concrete

If you need to remove acrylic sealer from concrete, you have two choices.

First, you can choose a mechanical option, as those work on practically any sealer. If the sealer is largely intact, sanding, blasting, or grinding are usually your best bets. If the sealer is flaky or coming up, power washing may work.

Second, you can use a chemical stripper. For acrylic sealer, solvent-based strippers are usually the most effective and fastest. However, some biochemical strippers designed for acrylic sealers may also work well. Just be aware that biochemical strippers take longer to do the job, so patience is required.

Does Vinegar Remove Sealer from Concrete?

VinegarGenerally, the idea that vinegar is an effective option for removing sealer from concrete is a myth. While vinegar is acidic, most concrete sealers are acid-resistant. As a result, vinegar isn’t particularly effective.

Additionally, while vinegar may not impact the concrete sealer, it can potentially damage concrete. If any of the sealer is worn through, allowing the vinegar to penetrate the concrete below, it can speed up breakdown and cause erosion.

Will Baking Soda Remove Concrete Sealer?

Baking sodaBaking soda is a popular cleaner, but it won’t remove concrete sealer on its own. Even scrubbing with baking soda won’t do much to remove the sealer, as the amount of scrubbing time required wouldn’t be practical.

Still, baking soda can be part of the removal process. Soda blasting uses sodium bicarbonate – which baking soda is made of – as the removal medium.

Does Muriatic Acid Remove Concrete Sealer?

muriatic acidMuriatic acid doesn’t work on all types of concrete sealer, as it often has little to no effect on cured polyurethanes, epoxies, or acrylics. However, it may work on other types of sealers, though this approach usually isn’t recommended.

Working with muriatic acid is hazardous. Additionally, muriatic acid can damage the underlying concrete if it’s not diluted correctly and left to sit too long.

If you decide to try muriatic acid, you need to read the manufacturer’s directions carefully. Make sure you dilute it as directed, and don’t let it sit longer than recommended. You also want to do a pH-neutralizing wash after you’re done. Baking soda is usually the simplest and most accessible option.

Will Acetone Remove Sealer from Concrete?

Acetone is a component in many solvent-based strippers, so it can remove sealer from concrete. However, using acetone alone is not necessarily the best choice.

One of the challenges of relying solely on acetone is that acetone evaporates quickly. Since it evaporates fast, it doesn’t sit on the sealer long enough to break it down sufficiently. As a result, many applications would likely be necessary, which is cumbersome and potentially costly.

While solvent-based strippers can contain acetone, other materials are involved with slower evaporation rates. As a result, the stripper is designed to remain viable long enough to break down the concrete sealer effectively.

How to Strip and Refinish Stamped Concrete

Stripping and refinishing stamped concrete is typically more difficult than working with a relatively smooth slab. Stamped concrete has much more texture, and getting the sealer out of the grooves, dents, and divots is challenging.

Due to the texture, most mechanical methods aren’t ideal. The mechanical approaches can wear down part of the concrete surface, so you could accidentally remove some patterning.

Instead, go with a chemical-based stripper to remove the concrete sealer. That leaves more of the texture intact. Plus, the stripper can work its way into the various grooves, dents, and divots with relative ease, increasing the odds that you’ll do a thorough job in less time.

The type of stripper you’ll want to use depends on the kind of concrete sealer that’s in place. As a result, consider doing the xylene test in an inconspicuous spot to see if the sealer is water-based or solvent-based first.

Doing the test spot with the stripper is also recommended, particularly if your concrete surface has colorants. Doing a test lets you see if removing the sealer will alter the look of your stamped concrete before you move forward with the entire surface. Then, you can plan accordingly or adjust your approach if you need to restore the color or want to keep colorants on the concrete intact.

What Is the Best Way to Remove Sealer from Concrete

The best way to remove sealer from concrete depends on whether you prefer a mechanical or chemical-based approach, the type of sealer involved, and whether your concrete is highly textured. Sanding, blasting, and grinding work on all types of sealer, but they aren’t the ideal choice if you have stamped concrete. Strippers are excellent options, but you need to choose the right type based on the kind of sealer that’s on the surface.

Did you learn everything you wanted about removing sealer from concrete? If so, let us know in the comments. Also, if you know someone who needs to remove concrete sealer from their surfaces, please share the article.

 

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