Concreate, Inc. delivers concrete polishing and custom staining for both commercial and residential projects primarily in Virginia and Maryland (but also up and down the East Coast). We work hand in hand with with designers, architects, project managers, general contractors, tradesmen, and home owners alike from start to finish. We welcome the opportunity to serve your polished concrete needs in every way possible.

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How to Protect Concrete: The Differences Between Guards and Penetrating Sealers

How to Protect Concrete: The Differences Between Guards and Penetrating Sealers

Using the proper floor protection for your project adds durability and longevity

Key Takeaways:

  • Guards and penetrating sealers protect concrete floors in different ways
  • A guard goes on top of the floor, changing its appearance and offering physical protection
  • Penetrating sealers soak into the concrete and alter its chemical composition
  • Using both forms of protection provides the best coverage

You’ll hear terms like guards and sealers as you work through your concrete flooring project. While contractors sometimes use these terms interchangeably, there’s a clear difference between guards and penetrating sealers that you’ll need to be aware of before you begin.

A guard is a liquid applied over the top of the concrete, creating a barrier between the floor and its surrounding environment. A penetrating sealer infiltrates the concrete’s surface, creating a chemical reaction within its pores.

You can use a guard or a penetrating sealer on your concrete project, and applying both is also possible. Here’s a look at how to protect concrete using guards and penetrating sealers and some information about each product type. 

An overview of guards

Guards typically eliminate the need for a resin-based or acrylic sealer. They go on as a liquid and provide stain and etching resistance, prolonging your floor’s lifespan. 

Many guards are water-based, and some products include a hardener that makes the concrete even more durable. These products can protect standard, dyed, stained, or color-hardened floors and provide a high-gloss finish so your floors will look as beautiful as they are functional. You can also polish the floor after applying the guard if you seek a higher gloss level.

While guards don’t create the same protective layer as a coating sealer, they prevent contaminants from penetrating that concrete, giving you time to clean up spills before they have time to do permanent damage.

Types of guards

You can choose from multiple guard types on the market depending on your needs. Low VOC options are also available when working in an enclosed space.

As you might have guessed, exterior guards are specially formulated for concrete that sits outside. These products add a protective shine and are usually good at protecting against petroleum-based spills that could permanently damage the concrete. 

Some concrete guards include anti-microbial additives that protect against bacteria and fungal microbes. These products work well in food-preparation environments where mold and other contaminants could form when something is spilled on the ground. 

Guards dry quickly and won’t discolor, peel, or flake, making them a solid choice when time is of the essence, but you don’t want to sacrifice quality. They’re also more economical than sealers, so they could better fit into your budget.

What is a penetrating sealer?

A penetrating sealer differs from a guard because it doesn’t cover the surface to protect the concrete. Instead, this sealer infiltrates the concrete’s surface, reacting chemically with the pores and altering the concrete’s composition. The result is a natural-looking surface that offers protection against moisture and chemicals.

You’ll typically use penetrating sealers outdoors because it protects from freeze-thaw damage, but using them inside on warehouse floors and other high-traffic locations where deterioration caused by surface abrasion is likely adds another layer of protection. There are a few penetrating sealer types, too, which you’ll select based on the application you have in mind.

Penetrating sealer types

When selecting a penetrating sealer for your project, you can choose between four distinct types: sodium silicate, lithium silicate, siliconate, and silane-siloxane.

Sodium silicate and lithium silicate are similar, as they both penetrate your floor’s surface, reacting chemically within its pores and forming a permanent crystalline structure that prevents moisture, salt, and other pollutants from penetrating it. Silicate sealers also add strength and density to the floor, stopping surface abrasions from causing damage. 

The seal, in this case, is permanent, so you can only remove it by removing the concrete itself. While moisture-resistant, silicate sealers don’t repel water, so you’ll need to add a guard for further protection if you’re applying it in a location where that’s a concern.

Siliconate sealers are water-repellent, making them a top choice in locations with a lot of moisture. These penetrating sealers react chemically below the floor’s surface, forming a hydrophobic barrier that reduces water and salt absorption into the concrete. As a result, siliconate is a solid choice for outdoor applications like driveways or garage floors that encounter plenty of moisture. One drawback is that siliconate sealers only last about ten years before requiring reapplication.

Silane-siloxane sealers are also water repellent, although their ability to bead water fades quickly. These sealers continue to work within the concrete’s pores for up to ten years, providing solid water resistance and preventing mold formation. You’ll often use silane-siloxane sealers in warehouses, shops, and other industrial settings, although you can use them around the house as well.

The penetrating sealer you select depends on where you’ll apply it and the type of defense you require. You can also use penetrating sealers and guards together for added protection.

Other sealers

There are also three sealer coatings from which to choose: acrylic, polyurethane, and epoxy. All three have pros and cons to consider as you make your selection.

Acrylic sealers form a thin protective coating on your floor and are the most economical option. They provide solid protection against water and chloride and are usually dry to the touch in about an hour. However, acrylic guards wear faster than other options and require regular maintenance when applied in high-traffic areas. 

Polyurethane sealers are almost twice as thick as their acrylic counterparts, creating a high-build protective film that is chemical and abrasion resistant. They also protect against water damage so you can use them indoors or outdoors. The finish is transparent and comes in various sheen levels, allowing you to customize your floor’s appearance. It’s worth noting that most urethanes won’t tolerate moisture until they cure, so you’ll have to be careful with outdoor applications.

Epoxy sealers work great in high-traffic areas because they’re thick, hard, abrasion-resistant, and long-wearing. They also create a glossy finish, but you can add color if you wish. The main issue with epoxies is that they turn yellow when exposed to UV rays, so they’re best reserved for indoor projects.

Protecting your concrete floor

Keeping your polished concrete floors in excellent condition is a priority, and you also want to attain the correct appearance for your application. Starting with a penetrating sealer to add durability and then adding a guard at the end of the process for additional protection and a glossy sheen ensures your floor will look great for years to come while minimizing the necessary maintenance.

Concreate does everything but pour the concrete, as we can install the penetrating sealers and guards you need to protect your floors. The result is a long-lasting and durable surface that will stand the test of time. Contact us or visit thisisconcrete.com for more information on the differences between guards and penetrating sealers.