How To Tell Whether Your Concrete Has Been Sealed

Concrete finishing is one of the most frequently asked questions: how can I tell if my concrete floor has been sealed?

First, determine whether the concrete has previously been sealed before applying a coating, paint, or sealer.

Surfaces that have been sealed will repel any coating applied to them. Therefore, it is important to perform a sealer test. You are checking to see if your concrete has been sealed or waterproofed.

Pour water onto your concrete surface to determine if it has been sealed. Water should bead up and stay in the sealed area. The coating will be safe to apply if it has been absorbed in a few seconds or minutes.

Applied coatings must cure at least 28 days after newly poured concrete has been poured. Don’t let the contractors add any ‘cure and seal’ products to concrete if you want a coating on it.

Water Drop Test Explanation

Water Drop Test Explanation

The good news is that it’s usually not hard to figure out. A water drop test is the fastest method. The process involves dripping small amounts of water over different areas of the concrete in your garage.

The concrete does not change color much when water beads up on it, so your concrete definitely has a sealer.

Nevertheless, if the concrete turns dark and absorbs water within a few minutes, the concrete does not have a sealer.

Not Sure If Your Concrete Has Been Sealed?

If your garage floor is sealed, a water drop test may be inconclusive and leave you unsure whether you need to do anything about it.

Smooth, non-porous concrete can be achieved with hard-troweled or power-troweled concrete. Water on the surface may take a little while to settle and absorb into concrete or evaporate.

Following the concrete’s removal, the next step is to test it with a muriatic acid solution that is made up of approximately four parts water and one part acid.

The acid solution should be applied to the surface in a few drops. There is no sealer present if the solution bubbles and fizzes.

In this case, it is clear that there is a sealer on the concrete because the acid solution sits there without doing much.

Due to the free lime in concrete, acid can only dissolve when exposed to it. Sealed concrete prevents the acid from coming into contact with free lime, resulting in fizzing and bubbling.

One of the most common mistakes when coating a garage floor is acid-etching sealed concrete.

What Is The Purpose Of Testing Sealed Concrete?

What Is The Purpose Of Testing Sealed Concrete

For coatings, paints, and other topical film-forming sealers to adhere correctly, the surface must be penetrated.

In addition, it is necessary for penetration sealers to penetrate into concrete to form a sealed barrier with the substrate. Therefore, both types of products will not work on concrete that has already been sealed.

What Is A Concrete Sealer?

An easy way to keep concrete clean and give it longevity is with concrete sealer. Applied sealer to new concrete should be left to cure for at least one month.

Cement sealants penetrate deep into the porous material, filling air pockets within and strengthening the material simultaneously.

Salt and mag-chloride are used in winter to keep roads de-iced, and concrete sealants are used to prevent erosion. Take a look at the weather before you apply it.

For the sealer to adhere properly to concrete, it needs to be applied when the concrete is dry. Application and drying might take up to three days if the temperature stays above 50 degrees Fahrenheit.

How To Remove Sealer From Concrete?

How To Remove Sealer From Concrete

Since you are removing the concrete material, this is a little more complicated than checking whether it has sealer. To do this, you need a combination of tools:

  • Citra Peel is an excellent sealer remover
  • Pad for stripping black
  • Diamond Pads

Citrus Peel is a natural cleaner that smells like oranges. Water-based, non-flammable, and easy to use, this remover is safe for all surfaces.

The first thing you will do is apply the Citra Peel to the affected area. Ensure that the area is completely covered – there’s no need to be extravagant.

You will then need a Black Stripping Pad. If combined with Citra Peel, these will do wonders for lifting sealer off the ground when run wet on the bottom of a low-speed floor buffer.

Last but not least, you need a Diamond Pad like our Concrete DNA Diamond Pads to follow this up.

With the Citra Peel and Stripping Pad, you’ll remove the sealer, then with the Diamond Pad, and you’ll etch into the concrete the grooves you need to apply a new sealer and polish your concrete.

Misconceptions About Concrete Sealing

Misconceptions About Concrete Sealing
  • There is no guarantee that someone did not seal your concrete if there is no beaded water or conditions found in unsealed concrete.
  • Unsealed concrete can suffer from conditions similar to those caused by inadequate sealants.
  • You should also consider how old the house is. A new coat of sealant may be needed if the adhesive wears off over time.

Note From The Author:

Among the things we neglected to mention was the use of cure and seal agents, which are commonly applied to freshly poured concrete.

Sealers like this help prevent moisture from escaping from concrete too quickly during curing.

In this way, the surface is more likely to cure consistently and will be less likely to crack or curl. Another reason to test is to see if curers and sealers can be applied without causing damage to the surface.

It is always best not to assume a concrete slab doesn’t have a sealer unless you know its exact history. It’s not necessarily bad if there is a sealer on the surface. Concrete can only be removed by grinding it.

Final Words

When you grind your floor, you’ll not only remove the sealer, but you’ll also prepare the surface. You may be able to prepare concrete without a sealer by acid etching if there is no sealer present.

A good concrete cleaning may be all that is necessary before applying some sealers and floor coatings. You should always check with your product’s vendor or manufacturer if you are in doubt.

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