How to Determine if Your Concrete Has a Sealer: A Step-by-Step Guide 

 March 13, 2023

By  Dale Keese

Step aside, you DIY-ers and home improvementers, it's time to learn how to tell if your concrete has a sealer. In a world where there are so many options for dealing with concrete, it's easy to get overwhelmed and unsure of what exactly is best for your own project. But not to worry, because today, we're walking you through an easy step-by-step process for determining whether or not your concrete has a sealer.

To determine if your concrete has been sealed, you can perform a water test. Place a small amount of water onto the concrete surface. If the water starts to soak in, the concrete is unsealed. If the water beads up, this indicates that your concrete may have been previously sealed.

No more second-guessing - with this guide, you'll no doubt be able to make the best decision for your concrete in no time at all! So grab your hard hats and safety goggles, because we're about to get down to the nitty-gritty of sealers and concrete. Now let's get to it!

Identifying if a Sealer has been Applied to the Concrete

It is important to determine whether or not your concrete has had a sealer applied to it, as this affects how you will treat the surface going forward. There are various ways you can identify if a sealer has been used, these include color change, gloss level, and surface water absorption.

  • Color Change: This method requires some prior knowledge of what the sealed concrete looks like when freshly unsealed. Some sealers will cause the concrete to become slightly darker or lighter in color after application, especially when stone aggregate is present. If color changes have been observed since being laid it would indicate that a sealer had been applied.
  • Gloss Level: Sealers present on the concrete will give it a distinctive sheen that is often higher than prior to sealing. A minimum effort visual assessment combined with an angle of light source can help indicate if the surface appears visibly glossy when compared to an unsealed area nearby. It should be noted that clays and other natural waxes may create conditions on big box store products which look similar.
  • Surface Water Absorption: A simple way of identifying whether a sealer is present is by sprinkling water droplets onto the surface in question. If sealed, most sealers will create an effect where after 5-10 minutes, some of the droplets remain on the surface whereas any unsealed portions will absorb water more easily within 1 – 2 minute timeframe.

Debating both sides of this argument might include looking at DIY vs professional installation methods and considering commercial products with inherent “sealing” components such as waxes or clays which may give a false indication of sealant applications. For example, while DIY methods typically produce uneven results with potential for areas being missed and/or over applied, professional installation competencies often result in water proofing services that are appropriately assumed as necessary maintenance measure while they may underperform when compared to recent product technologies making them an unreliable indicator even when properly done.

Additionally, commercially available paver and walkway applications often come pre-treated with sealing waxes or other natural compounding agents which make it difficult to accurately assess based on water absorption methods discussed here and potentially require additional tests due to changing technologies in their manufacturing processes over time.

Given all these considerations, identifying whether or not a sealer has been applied to concrete can be quite challenging and requires detail oriented assessment of both visible signs along with more scientific testing if inconsistencies exist across test sites. Fortunately, in the next section we will discuss examining the surface which can help provide valuable clues into determining whether your concrete has had a sealant applied successfully.

Examining the Surface

When inspecting a concrete surface for the presence of a sealer, it is important to pay special attention to the condition of the concrete. A visual inspection can often reveal any issues with the surface or coating that may require further investigation.

First and foremost, look for signs of wear or damage such as cracking or peeling. Not all sealers are designed to last forever and some may need to be reapplied after a certain amount of time. If you notice any signs of deterioration in the sealer, it may be a sign that it needs to be replaced.

It is also important to pay attention to the appearance of the concrete itself. Is the color uniform across the entire surface? Sealers can provide protection from dirt and staining, but in some cases they can alter the natural look of the concrete. Make sure there are no obvious variations in color or texture between areas with and without sealer.

Finally, inspect for any discoloration on the surface. Dark stains may be an indication that either rainwater has penetrated through a poor quality sealer or chemical reactions have occurred due to contact with acids or other corrosive materials. If this sort of discoloration is present, its origin should be investigated further.

Once you have inspected the surface, it is worth performing a wetting test to get an idea of how much water has penetrated through any existing sealer layers before moving onto more complicated methods of analysis. This section will discuss how best to carry out a wetting test in order to determine if your concrete is adequately sealed.

Performing a Wetting Test

When it comes to testing if your concrete has been sealed, the wetting test is one of the simplest and most commonly used methods. To perform this type of test, you will need a spray bottle, water, and a cloth or rag.

Begin by lightly misting some water over an area of concrete that is about one square foot in size. After doing this, use the cloth or rag to carefully dab away excess water from the same spot. At this point you should be able to notice whether or not your concrete has been sealed. If the water beads up on the surface and does not penetrate it, then it is likely that your concrete was sealed at some point. However, if the water is absorbed into the surface micro-fractures and pores, then it is an indication that your concrete has not yet been sealed.

In some cases, it can be difficult to interpret the results of a wetting test with certainty as not all sealers are created equal. Some sealers may still allow water to penetrate the surface but at a much slower rate than unsealed concrete. Conversely, other more high-grade sealants could repel all water droplets despite having a porous surface exposed. Thus if you are unsure of your results, it may be advisable to double-check them by performing additional tests such as the reactions with objects or liquids test which we'll discuss in the following section.

Reactions with Objects or Liquids

Reactions with Objects or Liquids is a method for determining if your concrete has a sealer that some might find cumbersome and time consuming. This route requires rubbing the test area of concrete with a paper towel or rag as well as a drop of water and/or an oil-based liquid such as paint thinner or acetone. For those attempting this type of test, it is important to make sure the reaction called out below is done on a small area of the concrete or the results may not be accurate.

When testing with a paper towel, it should drag across the surface of the concrete with ease if no sealer was applied or stick if a sealer is present (there will be resistance when rubbing). When testing with liquids, there should be no pooling in the case of an unsealed concrete, as liquids will bead when a sealer has been used. Further, if you take paint thinner, acetone, etc., and rub large sections of the concrete that have been sealed, you may see white residue from waxes and silicones contained within most commercial sealers.

In terms of accuracy and reliability, reactions with objects or liquids can be equally hit-or-miss for many do-it-yourselfers. Some prefer to use this method because it does not require any specialized items such as latex gloves and eye protection for safety. However, either way you decide to do it, caution must be taken so that too much area isn’t tested at once which could cause inaccurate results.

Many professionals recommend spot tests instead in order to gain an idea of what type of sealer is present on a particular slab before proceeding with more extensive testing. In the next section we'll discuss Quick Spot Tests for Determining a Sealer.

Reactions with Objects or Liquids is a method to determine if concrete has a sealer. This method involves rubbing the test area of concrete with a paper towel or rag and/or a drop of water and/or an oil-based liquid.

An unsealed concrete will cause the paper towel to drag across the surface with ease and liquids should not pool; whereas, a sealed concrete may stick when rubbed with the paper towel and will bead when liquid is applied. 

This method can be hit-or-miss and caution must be taken to not test too much area at once in order to get accurate results; spot testing is recommended by professionals for this purpose.

Quick Spot Tests for Determining a Sealer

Quick spot tests are an effective and relatively simple way to help you determine if your concrete has a sealer. The simplest, most basic test involves sprinkling water on the surface. If the water beads up and stays on the surface, this indicates that the concrete is sealed. However, this is not a foolproof method; there may be other reasons why the water beads on the concrete. Another test is to use a piece of tape and adhere it to the surface of the concrete. Then, try peeling it off and observing if any wax-like material adheres to the tape. If it does, then it’s likely that your concrete has been sealed.

One of the most reliable methods for determining if your concrete has a sealer is to apply paint stripper or a de-glossing agent to a small area of the concrete surface. These agents dissolve waxy, glossy surfaces that tend to indicate that the concrete has been sealed, so if you notice the surface becoming dull after applying these substances, it's likely that your concrete has been sealed.

It's important to note when performing these tests that they do not always yield conclusive results – some sealers are designed to be invisible to ensure longevity; as such, these tests may not be successful in determining whether or not your concrete has been sealed with such products. Ultimately, professional testing should be done for definitive results.

Having said that, armed with some basic knowledge about how to determine if your concrete has a sealer, you can easily move on to removing existing sealant from your concrete if necessary. One sentence often says more than any number of words could ever convey: next we will discuss how exactly to remove existing sealant from your concrete.

Removing the Existing Sealant

When it comes to determining whether or not your concrete has a sealer, the first step is to remove any existing sealant before attempting to apply a new one. This is an important step because if you attempt to apply new sealer over an old coating, it may cause issues down the line.

There are two primary tools used when removing existing sealant: chemical strippers and mechanical surface cleaners. Chemical strippers come in either acid- or alkaline-based formulas and can be effective when working with thicker layers of sealers. Be sure to wear safety glasses, gloves, and use proper ventilation when using chemical strippers. Mechanical surface cleaning devices such as hand-held grinders and abrasive blasting systems are also effective for removing large areas of sealant. Both types of removal processes will require rinsing the area thoroughly afterwards with water or a chemical cleaner to ensure that all debris is removed from the area.

Once the existing sealant has been removed, it’s important to test the substrate in order to ensure that it is compatible with the new product you plan on using. There are a variety of tests available that will help you determine if there are any contaminants on the surface or in the substrate or if there are any other conditions that could affect adhesion or performance.

Now that the surface has been properly prepped and tested, it’s time to select the appropriate product for re-sealing your concrete. The next section will discuss how to select the right product for your application.

Selecting the Appropriate Product

When determining if your concrete has a sealer, it is important to select the right product for the job. The type of sealer used will depend on factors like the type of material being sealed and its existing condition. For example, if you are sealing concrete outdoors, a water-based acrylic sealer would work best. On the other hand, an oil-based polyurethane sealer might be best suited for indoor surfaces, such as a kitchen countertop. It is important to note that there are different types of sealers available, so selecting the right one should not be taken lightly.

When it comes to selecting a concrete sealer, there are two primary arguments: for using a professionally installed product or for using a do-it-yourself solution. Each scenario offers unique benefits and drawbacks.

A professional installation will ensure that the entire surface area is properly sealed and that any cracks or crevices have been filled in correctly. However, this also tends to be more expensive than purchasing a do-it-yourself solution.

Alternatively, purchasing a do-it-yourself solution can give you more control over the application process and allow you to customize the finished product in ways that suit your needs. Do-it-yourself solutions may also be less expensive than a professional installation, depending on the situation. However, they often require more effort and skill to apply correctly and may not provide as thorough of coverage as a professionally installed product would offer.

No matter which option you choose, it is important to take care when selecting an appropriate product as this could greatly affect your chances of achieving successful results when attempting to determine if your concrete has a sealer. Now that we've gone over several factors to consider when selecting an appropriate product, let's move on and discuss how strengthening the concrete slab can help improve durability in the next section.

Strengthening the Concrete Slab

Once you have determined if your concrete slab has a sealer, it is important to consider what type of strengthening treatments it needs. Depending on the condition of the slab, there are several options available such as troweling and overlaying, polishing, grinding, or even using epoxy coatings.

Troweling and overlapping can help reduce cracking or spalling in the concrete slab. It involves a process of smoothing out any surfaces that may have been damaged due to weather conditions or wear and tear over time. This can help strengthen weak spots which may have contributed to a weakened concrete slab overall.

Polishing is another option for strengthening the concrete slab. This technique involves using diamond abrasives to make the slab smoother and more resistant to damage from wear and tear, as well as from water and other elements. Polishing also increases reflectivity and gives your project a more professional look.

Grinding is a way of grinding down the existing surface of the concrete for a uniform finish, allowing for easier maintenance down the road. This method is often used when dealing with high traffic areas where a flat surface can be beneficial for many reasons including longevity of the material beneath.

Epoxy coatings can be applied to a concrete slab as an extra layer of protection from damage caused by weathering or wear and tear over time. Furthermore, epoxy coatings provide chemical resistance against stains like oil and salt while also improving abrasion resistance, making it an ideal choice for outdoor surfaces that get lots of foot traffic.

The debate of whether or not these strengthening treatments are necessary comes down to personal preference; those looking for long-term durability may choose one option while those who prioritize convenience might opt for another treatment option. In either case, assessing your surface’s condition will enable you to make an informed decision about which strengthening treatment best suits your needs. Ultimately, a strengthened concrete slab can prevent further deterioration due to excessive use or environmental factors.

Now that we have gone through different options for how to strengthen a concrete slab, it is important to consider what type of conclusion should be drawn about this topic in order to answer all questions that readers may have had in regards to reinforcing their surface before sealing it.


When it comes to determining if you have an existing concrete sealer, it pays to stay vigilant. Knowing the signs and symptoms of sealed concrete is essential for ensuring that your concrete stays in its best condition in the years to come. While there are different methods to determine whether you have a sealed concrete or not, the best way is through a thorough visual inspection and completing a water absorption test. Depending on results, you can quickly and easily identify whether you’re in need of resealing your surface, or starting fresh with a brand new sealer.

When resealing, it’s important to make sure you pick the right product, otherwise you might end up having more problems than solutions. One key difference between sealers is penetrability. Sealers with high penetrability will be able to penetrate deeper into the concrete and bond better with existing layers of sealer; creating a more solid protective layer for your surface when compared to low penetrability sealers. Using the wrong type of product could mean that whatever protective layer you’ve created won’t be as strong or resilient enough against damage from wear and tear.

Overall, looking after your concrete surface will ensure that it stays in good condition for many years to come. Knowing how to identify if your concrete has been sealed is just one step towards becoming familiarized with preventive maintenance practices used by professionals. This knowledge can help educate individuals on whether their surface requires resealing or if it’s time to start fresh with a new layer of topical sealer—ultimately protecting your investment while having optimal results over time.

Frequently Asked Questions

What are common signs or symptoms of a sealed concrete surface?

Common signs or symptoms of a sealed concrete surface include:

  1. A glossy sheen – Sealed concrete surfaces often have a glossy shine that makes them look polished and smooth.
  2. Increased Durability – Sealed concrete surfaces tend to be more resistant to scratches, dust, and stain damage than unsealed surfaces.
  3. Reduced Porosity – Sealed concrete surfaces are less porous and resist absorbing moisture, meaning it won’t collect dirt and debris as easily as unsealed concrete does.
  4. Improved Color Retention – Sealing your concrete with a sealer can protect the color underneath from fading over time due to natural wear and tear.
  5. Enhanced Stain Resistance – As mentioned before, sealed concrete is much less likely to absorb liquid from spills and other sources than unsealed surfaces are, making them easier to clean up quickly.

What materials or methods can I use to test for a sealer on concrete?

Testing for a sealer on concrete can be done using a few methods including:

  1. Water Test: This method is a simple and cost-effective way to test if your concrete has been sealed. Put a few drops of water on the surface, and if it beads up and pools together, this means that the surface is sealed.
  2. Staining Test: If you are unsure after performing the water test, you can conduct a staining test by pouring liquid of a different color onto the concrete resulting in no absorption or stain which indicates it has been sealed.
  3. Solvent Test: Finally, you can use a solvent-based material to determine if there is an existing sealer on concrete. You should apply one small drop of the solvent-based material onto the surface of the concrete and see if it dissolves or beads up. If it dissolves, it means your concrete does not have a sealer applied; however, if it beads up, then it suggested that there is an existing sealer on the surface.

Overall, these methods will help you determine whether your concrete has been sealed with ease!

Are there any special precautions I should take when testing for a sealer on my concrete?

It's important to always take caution when testing for a sealer on concrete surfaces. Some sealers, such as epoxies and acrylics, contain hazardous chemicals that require special handling and ventilation, so wearing protective gear such as gloves and a respirator is recommended. Additionally, the test area should be thoroughly wetted down, and any nearby plants or vegetation should be covered to avoid contact with the chemicals.

Finally, if the sealer you're using is in liquid form, it's very important to make sure that you are following the manufacturer's instructions exactly — any deviation from their process could lead to an incomplete or faulty seal.

About the author

Hey, I'm Dale Keese.. thanks for reading.. hopefully this article can save you some time and trouble with your sealing job. I'm also in the process of making some video walk-throughs for youtube so check back soon! thanks

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