How to Remove Concrete Sealer

Which kind of sealer is on your concrete?

Do a water drop test first. Sprinkle a few drops of water on the slab: if they soak in within 3 to 5 minutes, the concrete is bare or its sealer has worn out, and it can take new sealer. If they bead up, something is still sealing it, and the surface tells you what.

• A shiny or “wet look” surface, or a coating that peels or flakes: a topical film. The sealer maker’s FAQ says topical sealers sit on top of the concrete, and that acrylics can become brittle, peel away with age or yellow.
• No sheen and no change in texture, but water still beads: a penetrating sealer. It reacts inside the surface, and the PS100 data sheet says that product won’t peel or delaminate.
• Not sure: scrape a hidden spot with a razor blade. The maker’s FAQ lists scraping as one way to remove a topical sealer, so if a thin skin comes up, it’s a film.

The penetrating vs topical guide explains the two types in more detail.

Can you remove penetrating concrete sealer?

No, and you don’t need to. A penetrating sealer sits inside the pores rather than on top, so there’s no film to strip. The PS100 data sheet says it “does not need to be stripped or removed for reapplication.”

What fades is its water repellency. A review of penetrating sealer research (opens in a new tab) for Iowa State University found that sealer performance drops over time from sunlight, wear, weather and alkaline attack, so reapplication is needed. When the water drop test shows drops soaking in again, clean the slab and reseal.

If your problem is a white haze from too much penetrating sealer, that’s residue on the surface, not something to strip. The sealer turned white guide covers how to clear it.

How to strip concrete sealer with a chemical stripper

Soften the film with a stripper made for concrete sealers, scrape it off, then rinse the slab thoroughly. Every product differs in how long it sits and what it works on, so the stripper’s label sets the details. The steps below are the order of work.

1. Read the label

   The Consumer Product Safety Commission (opens in a new tab) says to read and follow the stripper’s label every time you use it. It sets the dwell time, coverage, temperature range and cleanup.

2. Test a small area

   Try the stripper on a hidden spot first. The National Park Service’s guide to cleaning masonry (opens in a new tab) notes that removing a coating may take testing more than one product.

3. Protect what's around the slab

   Cover plants, siding, doors and anything else the label warns about. Work outdoors if you can.

4. Put on your gear

   Wear the chemical resistant gloves the label or safety data sheet calls for (the CPSC gives butyl rubber and neoprene as examples), plus goggles and clothing that covers your skin. The CPSC says household latex gloves don’t protect enough.

5. Apply the stripper

   Spread it at the thickness the label gives and leave it for the full dwell time. Work in sections you can finish.

6. Scrape off the softened film

   Push the sludge into a pile with a floor scraper and collect it before rinsing. Bag it and dispose of it the way the label says.

7. Rinse thoroughly

   The NPS says whitish deposits left by chemical paint removers come from inadequate rinsing or leaving the chemical on too long, and may be impossible to remove. Rinse until the water runs clear.

8. Repeat where the film remains

   Thick or layered sealer may need a second application. Do the water drop test on the clean, dry slab to check for spots you missed.

Is concrete sealer stripper safe to use?

Only with the right gear, good air flow and the label followed. The CPSC warns that stripper chemicals can irritate skin and eyes and cause headaches and dizziness, and that some can cause cancer or damage the liver, kidneys or brain.

• Methylene chloride: the EPA (opens in a new tab) banned it in consumer paint and coating removers after deaths from short exposures, and in 2024 banned it for all consumer uses. Don’t use an old can you find in the garage.
• “Citrus” or “safer” strippers: the CPSC says these can still contain NMP, which can cause skin swelling, blistering and burns. Wear gloves anyway.
• Caustic strippers: they can cause severe burns, according to the CPSC. Keep them off skin and out of eyes.
• Flammable strippers: no flames, pilot lights or sparks nearby. The CPSC warns that sparks from a fan can raise the chance of flammable fumes catching fire, and says never to use gasoline, lighter fluid or kerosene as a remover.

Indoors, such as on a garage floor, open doors and windows for cross ventilation and set a fan to blow air away from you and outside. If you can’t get good air flow, the CPSC suggests hiring a professional.

When should you grind or blast the sealer off instead?

When the film is thick, layered, or a tough coating like epoxy or polyurethane, or when you’d rather avoid solvents. The sealer maker’s FAQ lists grinding, sand blasting and shot blasting as accepted removal methods, and the TS210 data sheet says its cured coating comes off by mechanical removal or a commercial chemical stripper.

Grinding also roughens the surface, which a new topical coating needs. A grinder or shot blaster can be rented, and the rental shop can show you how to run it.

The dust is the hazard. OSHA (opens in a new tab) says grinding concrete creates respirable crystalline silica, which can cause silicosis, an incurable lung disease, as well as lung cancer and kidney disease. Use a grinder with a vacuum shroud, wear a respirator, and keep kids and pets away.

Removal methods from the sealer maker's FAQ and the TS210 data sheet; hazards from the CPSC and OSHA.

What do you do after the sealer is off?

Clean, etch if your new sealer calls for it, let the slab dry, and test it with water. A penetrating sealer needs open pores, and the maker’s FAQ says surfaces must be free of previous sealers, curing agents, paint and coatings before it goes on.

1. Degrease. Clean off oil and grease before the new sealer goes on. The data sheet for CC501 heavy duty concrete cleaner calls it a pre-cleaner for concrete about to be sealed; it’s highly caustic, so wear gloves and eye protection and keep it off plants.
2. Etch if needed. CC502 cleaner and etcher is made to etch concrete before penetrating sealers or topical coatings. The maker’s FAQ says to neutralize or rinse completely after any acid etch.
3. Let it dry. The PS101 guidelines say to allow 1 to 3 days after power washing or heavy rain before sealing.
4. Test with water. Drops that soak in within 3 to 5 minutes mean the surface is open and ready.

Which sealer should go back on?

A penetrating sealer, for most outdoor slabs, because it won’t need stripping next time. The PS110 data sheet describes it as not film forming, so it keeps the concrete’s natural breathing, and the PS100 sheet says that product won’t peel or delaminate.

A smooth garage floor where you want a sheen is the main case for going back to a topical sealer. The penetrating vs topical guide compares them, and the drying time guide covers how long each one needs before you walk or drive on it. The sealing guides cover the rest.