Why is my concrete sealer blotchy?

The culprits of blotchy concrete after sealing

The sealer was applied poorly. Not enough sealer was applied. The concrete itself had varying absorption rates.

Can you put too much sealer on concrete?

When the sealer is applied too heavily, the air displaced through the surface can't escape, and it forms a bubble in the sealer surface. Bubbling of a sealer can also occur if application is done in hot weather, or if the concrete is in direct sun.

How do you fix uneven concrete sealer?

Roller Marks/Streaks: Roller marks or streak marks occur when the sealer was applied too heavily, unevenly, or without maintaining a wet edge. Apply thin, even coats and if roller marks occur use Xylene to correct the problem.

How do you remove streaks from concrete sealer?

The most effective way to remove streaks on concrete sealer is by applying a small amount of xylene on the affected area. This would only work if you used a solvent-based acrylic sealer and if it's water-based, streaks must be corrected with xylene within 48 hours of application.

Why is my concrete drying different colors?

Discoloration on the surface of new concrete can be from several factors including inconsistent mixtures, too much or not enough water, low quality materials, poor workmanship, the use of calcium chloride, environmental issues, or issues created during the pore or during the curing process.

5 Common Decorative Concrete Sealer Problems and Their Solutions

Why is my concrete splotchy?

The culprits of blotchy concrete after sealing

The sealer was applied poorly. Not enough sealer was applied. The concrete itself had varying absorption rates.

What is concrete mottling?

Mottled concrete is irregular shapes of different shades of white- gray to gray-black. These blotches are restricted to the surface, normally only 1/32" to 1/8" deep. They can diminish over time but usually are permanent. The concrete is almost always sound and meets specification.

Can you sand concrete sealer?

Dry sanding is often used on water-based sealers. Use a 200+ grit screen to lightly sand the surface and knock down the lap lines, and then re-apply the same water-based sealer to even out the sanded surface. If the lap lines are severe, you may need to strip the sealer completely and start over.

Can you apply 3 coats of concrete sealer?

Two coats are always suggested because the first coat of any concrete sealer is usually absorbed into the concrete at different rates leaving the substrate unevenly sealed. A second coat will ensure proper even coverage.

Will a pressure washer remove concrete sealer?

A pressure washer can remove old concrete sealers. The sealer can be removed from concrete by using a pressure washer with a wand or an orbital walk-behind model. Keep in mind, however, that even though this method is effective, it may not completely remove the old sealer.

How many coats of concrete sealer should I use?

Concrete sealers are best applied in two thin coats. The first coat of sealer acts like a primer. Most of it will disappear into the concrete surface, and the concrete will probably look fairly unattractive after the first coat. The second thin coat will provide an even finish, color enhancement and gloss.

Why does New concrete have dark spots?

As the water evaporates to the surface and soaks into the cement that is an ingredient of concrete, it leaves behind darker spots where the cement contains more moisture. These will fade over time as the water eventually soaks into or evaporates out of the slab.

Is it better to spray or roll concrete sealer?

“Certain sealers are better applied by spray because they are not formulated for rolling,” says Dean Owen, president of Arizona Polymer Flooring Inc. in Glendale, Ariz. “This is usually a function of the solvents used in the formulation. Slow-evaporating solvents are better for rolling.

How long does concrete sealer take to cure?

Most concrete sealers dry fairly quickly and usually dry to touch within 1-3 hours. This is true of both penetrating and topical sealers. Penetrating sealers usually fully dry for traffic in less than 24 hours with topical sealers generally taking up to 48 hours to fully dry for traffic.

Will bubbles in concrete sealer go away?

For solvent-based sealers, blisters and other surface defects can usually be removed with a solvent bath (wetting the surface with acetone or xylene). This sometimes works with water-based sealers, but testing first is always recommended.

Does concrete sealer darken concrete?

Sealers, particularly solvent-based sealers, will darken concrete. If unevenly applied, it will create light areas where there is less sealer, and darker areas where there's more.

Can I put sealer over sealer?

Answer: In general, putting a solvent-based sealer on top of a water-based sealer is a bad idea. The solvents can eat or soften the existing water-based sealer, destroying both coatings. Think of it along the lines of oil and water; they do not mix.

How long does concrete sealer need to dry before rain?

Driveway sealer needs to be allowed 4–8 hours to dry before rain. Longer cure times are better, as it takes upwards of 24 hours for driveway sealer to completely cure, but under good conditions, 4 hours of curing time will be enough for your new sealant to resist rain damage.

What happens if you seal concrete too soon?

If you were to seal the concrete any sooner, it would create a barrier and prevent the excess moisture from evaporating correctly. As a result, the newly poured concrete driveway would not be as strong as it should be. In addition, the concrete would be more prone to breaking and cracking.

Can you apply concrete sealer over old sealer?

Before applying a new sealer, it's very important that you make sure the old one is completely gone. This is because any old sealer left on the surface of your concrete can impede the effectiveness of the newly applied sealant, preventing proper adhesion to the concrete surface.

Why did my sealant turned white?

A clear sealer which turns frosty white in color has delaminated from the concrete surface. This is most likely due to the coating's inability to release water vapor trapped within the concrete quickly enough to prevent pressure buildup beneath the coating.

Why is my driveway sealer shiny?

When they go door-to-door, that usually means you can see where they are working. If the sealer is drying shiny and glossy, that's a very bad sign. Good quality asphalt sealer should dry a flat, black matte. Shiny is slippery and will not endure.

How do you fix white sealer on concrete?

Solution: To fix you will need to remove the sealer with a concrete or paver sealer stripper. Trapped moisture under the sealer is the most common reason that the sealer has turned white. This happens to sealers that are not breathable or over-applied.

Why does my new concrete have white spots?

White stains or a white powdery coating on new concrete is not uncommon. Such discoloration, known as efflorescence, is caused by salts that are brought to the surface of new concrete by the natural curing process.

Why does concrete turn orange?

If there's a rampant amount of rust spots on a surface, there's a chance that fertilizer could have been spilled there, and the remnants have become orange spots along the ground. But, more than likely, the orange stains on concrete are the product of metallic minerals oxidizing and rusting within the concrete.