How to Seal Concrete Countertops: DIY Renovators Guide

Breakfast Counter

Concrete is porous by nature, which means that any stains can discolor or damage its quality. If your countertop is made of concrete, you will need to seal it to avoid any damage caused by acidic foods like vinegar, wine, mustard, and many others. Food may not be the only enemy of your concrete countertop, as everyday wear and tear caused by dragging pots and pans or water absorption – concrete’s biggest enemy – can leave permanent scratches and marks all over it.

Breakfast Counter

Sealing the countertop with the right kind of sealer will not only protect the countertop surface from discoloration and scratches, it will also enhance the color and sheen of the concrete surface.

With a large number of countertop sealers available in the market, it can be a little confusing to choose one. There are many factors that should be considered when you are choosing a countertop sealer so here are some things that you must keep in mind. In addition to this, we have also included a step-by-step guide for sealing concrete countertops that will walk you through the entire process.

Choosing the Right Sealer for the Job

Before you pick up the sealer for the job, it is important that you understand what is available in the market, how they work and what they are best suited for. While there are tons of concrete sealers, it is important to choose one that meets the specific performance requirements for countertops and not the generic ones that are commonly used on floors or exterior flatwork. The reason behind this is that the challenges faced by each surface are different.

Wooden Fruit Bowl on Countertop

 Some important factors to consider are given below:

  • The countertop sealer should be heavy duty so that it is safe for food. It is colorless, does not yellow and is resistant to heat and scratches.
  • Concrete countertops are usually inside the house, which means you will also be carrying out the sealing process indoors. While outdoor countertops are sealed outdoors so don’t cause any issue, you will need a product that is safe for indoor application for the former. This means that they should not contain any VOCs or harmful chemicals and should also be low in odor.
  • You can find products that come in a range of sheen levels. Use a sealer with a low-sheen matte finish for a more natural look, or a high-gloss sealing product if you want your concrete countertop to shine more.

  • While most countertop sealers take hours to stop feeling sticky and can take quite a few days before they are ready to use, you can opt for a fast curing sealer to speed up the process if you are in a hurry. These variants cure at a great speed when they are exposed to a special type of ultraviolet light.
  • In the end, it is important that you test the sealer that you are going to be using on your countertop. By doing this, you will be able to check the performance and finishing touches of the sealer that you buy so that you get the most out of it.
Herbs on Kitchen Counter

What Do You Need for Sealing?

The list of things that you will need when you are trying to seal your concrete countertop effectively is very small. All things can be found at any local supply store.

  • Concrete countertop sealer
  • Rubber gloves
  • 2 half liter buckets
  • Cloth towel with good absorption

Step-By-Step Guide to Sealing Your Countertop

While many people enlist the help of professionals to seal concrete countertops, the process is quite easy and can be carried out by you at home. Just put on your work gear and get started!

Counter with Metal Chairs

Step One – Ensure the Right Conditions

It is important that you seal the concrete countertops indoors or in an area that has ample amounts of shade. The process needs to be carried out in an area where the wind isn’t strong and there is no dust to hinder the process. It is important that the sealer doesn’t dry too fast as it can give an unfinished look to the final product.

Step Two – Dilute the Sealer

As 100% sealer can be quite difficult to work with, you will be required to mix it with water in this proportion – 30% sealer: 70% water. Using this mixture, you can apply a large number of fine layers so that the sealer is not clumpy. Different amounts of the product will be required depending on the nature and size of your countertop.

If the area to be covered is extremely large, you will have to buy a large container of the sealer being used. If the project is relatively small, even a 500 ml package will be enough to get you through.

Red Kitchenware on Countertop

Step Three – Soak Surface with Water

The next step involves rinsing the concrete well with clean water. You will be required to use a 100% cotton cloth for this step, as using a harsher cloth may damage the countertop or leave marks. You will be required to get rid of any remaining sealer or wax if the concrete countertop has been through this process before. This removal can be carried out with the help of specialized products. 

Another piece of cloth should be brought to wipe down the surface and the edges of your concrete countertop till the entire surface is saturated with water and has a dark look to it.

Step Four – Apply Countertop Sealer

As you will need to apply lots of coats, soak the cloth rag in the diluted solution that you prepared earlier and start applying it across the countertop. It is recommended that you begin with the corners and apply good amounts of it across the entire piece. Keep at it for at least five minutes so that the countertop is covered well.

Allow the sealer soak into the concrete and continue applying it in a manner such that you spread it evenly across the piece. You will have to work at a quick pace if the piece of concrete is large otherwise you may be faced with the problem of gelling and streaking that will ruin the look of your sealed countertop.

Countertop and Sink

Step Five – Wipe the Sealer

Use the same rag to wipe up the sealer and remove the excess into the bucket of diluted sealer that you were using. The aim here is to leave some amount of product on the countertop so that the surface doesn’t dry completely. Work quickly and in a shady place to avoid streaking.

If the concrete isn’t treated before, you will need to apply the sealer onto the concrete multiple times before it stops darkening when water is dripped on the surface. That is the ultimate test for a well-sealed countertop.

Step Six – Test with Water

Once you are satisfied that the concrete is sealed well and given at least a night to dry, you can carry out a specific test with a drop of water to gauge the efficiency of the sealer. Start off by pouring water on top of the concrete. Allow it to sit there for at least ten minutes and then wipe up all the water using a clean cloth. If you notice the surface darken at the end of this test, it means that it isn’t sealed well. Keep repeating steps three and four till your concrete countertop passes the test without the surface darkening. 

Once the countertop is sealed completely, you can lightly scrub the sealer with diamond-infused hurricane pads, which will allow you to get rid of any streaks that may have formed on the countertop in the process of sealing. You can also adjust the surface sheen with this.

Kitchen Countertop

Fixing Scratches on Countertop Surfaces

If you try cutting your fruits or vegetables directly on the surface of concrete countertops, you will definitely end up with minor scratches. Looking at the bright side, if your countertop is sealed well, the scratches will only be found on the sealer itself and not on the concrete countertop. In such cases, it is quite easy to fix these scratches. You can fix some minor scuffs and shallow scratches on the sealer by just buffing out the surface for a bit.

For deeper scratches, however, you may need to fill the scratch with an additional sealer to get the best results and restore your countertop to its former glory.

White Countertop

Sealing the surface of your concrete countertop is a very important step for increasing its lifespan. While you can change your pots and pans over time, the likelihood of changing countertops is much lower so you should make sure that it is sealed well. To save some money and to ensure that you are satisfied with the sealing process, you should carry it out yourself. If you need suggestions regarding what sealer will work best for your concrete countertop, you can read some reviews here.

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