Concrete Countertop Maintenance: Understanding Different Types of Sealer
You are interested in concrete countertops but you’re concerned about the maintenance. How much maintenance is required depends on the type of sealer you use. The type of sealer you choose can often depend on the finish of the concrete (polished, troweled, stamped, etc.). Some sealers aren’t able to adhere to a highly polished surface. Some sealers won’t give an adequate seal if you have too much texture or porosity. Some require resealing every year or so and some are good for the life of the concrete, but most are somewhere in between. Which sealer you choose will also depend on the desired finished look you want to achieve. Options such as color enhancing, glossy, matte or satin should all be a factor in your choice.
What is Sealer?
It is important to have a basic understanding of what sealer is and how it works. This way, you can better understand the differences between types of sealer and how that might affect the maintenance. At its most basic, sealer is made up of two parts, a resin (or the plastic component) and a carrier. The carrier will almost always be water (water-based sealer) or a solvent/ blend of solvents. The idea is that the carrier “carries” the resin onto or into the concrete and then evaporates, leaving behind the resin which will create a film or coating to protect the concrete.
Types of sealers and their properties:
When we discuss types of sealers, what we are talking about is the type of resin that is doing the protecting of the concrete. Almost all of our sealers are water-based but this guide will give you a broad overview of the primary types we sell.
Acrylic - Acrylics are usually thinner than polyurethane or epoxy sealers so they wear faster and usually require reapplication sooner. In most cases you will need to reapply every year or every couple of years. It’s important that these are applied thin so they typically won’t “fill-in” any pin holes or roughness. A lot of times, acrylic sealers are also penetrating sealers. They work by soaking into the concrete and saturating the pores while increasing the surface tension. This blocks liquids from getting down into the concrete. Acrylic sealers usually have a matte, natural looking finish. There are some acrylic sealers that are color enhancing but many are not. An example of this is our SiAcryl 14 which is a Silicone and Acrylic hybrid resin. It is a penetrating sealer with little to no color enhancing effects. It does work by saturating the pores of the concrete so it is important that when applying this sealer, it is worked into the concrete surface. With that said, if the concrete it too rough or porous, this sealer may not fully saturate the pores and therefore is best used on tightly troweled or polished concrete.
Polyurethane - Polyurethane sealers are very hard and exhibit good scratch/chemical resistance. As with most sealers, you have some options with polyurethanes. They can be water or solvent based, can be used indoor or outdoor, can be matte or gloss finish, color enhancing or not. Polyurethanes for concrete are usually much thinner than their wood counterparts. They are usually topical, film forming sealers however they are thin and in most cases, not meant to be built up. If you have texture or porosity and want a smooth, slick surface without polishing, you may want to think about something thicker like an epoxy. Both our Aqua-Thane M35 and G40 are water-based polyurethane sealers. The M35 is the matte version with no color enhancing and the G40 is color enhancing with a gloss finish. Both should last 5-10 years depending on the amount of wear the concrete sees.
Epoxy - Like polyurethanes, epoxy sealers can be solvent based, water based or 100% solids (no carrier to evaporate). They can be color enhancing or not. One great thing about epoxy resin is that it’s film forming and thicker than other types of sealers. If you have any texture or porosity, the epoxy will “fill in” the roughness and make it smooth to the touch. A water based epoxy like our Aqua-Poxy is very easy to apply. It’s rolled on in thin coats just like most other concrete sealers. You get the benefits of epoxy without much of the mess and hassle of traditional epoxies. Unlike some polyurethanes, epoxy sealers cannot be used outdoors. All epoxy will eventually yellow from UV exposure. Because of the thickness of the coating, epoxy is usually good for the life of the concrete. It will exhibit a heat resistance of around 400ºF. Since epoxy is not quite as hard as some of the previously mentioned resins, you may choose to recoat as time passes in order to cover any scratches or scuffs that have developed. In that case, you would scuff the surface with sandpaper and apply another coat.
Our Ultra Z Poxy is an example of a 100% solids epoxy. Meaning it is only resin and hardener with no carrier. This means that each coat can be built very thick and it will provide a glass like glossy surface. This product is color enhancing and will greatly darken the concrete or stains. One benefit of 100% solids epoxy is that you can add pigment or metallic powders to create beautiful colors and faux stone finishes. It can also be dulled by wet sanding in order to leave a matte finish that is less likely to show any scratches.
In conclusion, the amount of maintenance and limitations of your countertop are almost always going to depend on the sealer you use. However, there are a few things that you should never do, regardless of the sealer. All of the sealers we carry have a 300 to 500-degree heat resistance. As a general rule, it’s never a good idea to take a pan directly off the hot stove and place it on the countertop. Always use hot pads or trivets. Also, although some sealers are more scratch resistant than others, you never want to use a knife directly on the countertop surface. Your countertop is not a cutting board. That being said, each sealer has their own benefits and downfalls. Make sure you take into consideration the look you want, the durability and how often it needs to be reapplied.
Most sealers including Aqua-Thane and our epoxies, cannot be applied over highly polished concrete. For topical sealers, surface prep is key for adequate adhesion. Please make sure you follow the instructions for the sealer you are using.
With all of the sealers we carry, any mild kitchen cleaner is fine to use. Lysol, Clorox wipes, dish soap and warm water are all good ways to clean your concrete countertop. Stay away from anything abrasive. Don’t use Magic Eraser or Brillo Pads. If damage/discoloration/cloudiness does occur from using an improper cleaning agent, you can usually sand the area and spot fix with more of the same sealer. Your best bet is to give us a call and send us some pictures. We are more than happy to guide you to the best fix.