Film-Forming Sealers vs. Penetrating Sealers

What's the Difference between Film-Forming Sealers and Penetrating Sealers, and How to Make Your Choice?

If you’re in the business of laying and maintaining driveways, paths, gardens, and other features that use pavers, you’ve likely dealt with more than your fair share of sealers. Choosing the right sealer can be a challenge even with experience.

With so many types of sealers out there, it can be difficult to know which one to use for a job. You certainly can’t leave something so important up to chance or trial and error. Understanding which sealers are best for which situations can save you a lot of trouble and ensure that your customers are satisfied.

What Are the Different Types of Sealers for Pavers?

When you visit your local hardware store or check out a supplier’s catalog, you’ll find a wide variety of options for sealers. They offer different finishes and colors, along with features like same-day sealing and additional protection against specific threats.

The variety can seem overwhelming, but all sealers fall into one of two main categories. Penetrating sealers soak into the pores of the paver while film-forming sealers leave a distinct protective layer on the stone's surface.

Each type has unique properties and applications. There's also plenty of variety among each type of sealer, allowing you to choose from different finishes while still finding the right choice to deliver lasting results for the job at hand.

The Properties of Penetrating Sealers

Penetrating sealers work by soaking into porous materials. Once the sealer dries, it blocks those pores from absorbing water, oil, and other chemicals. They are generally easier to apply and deliver more consistent results than film-forming sealers. Without the risk of peeling due to improper application and environmental conditions, application is more straightforward.

Penetrating sealers generally provide a natural finish with little to no gloss but you can also find a range of wet-look and semi-gloss penetrating sealers. Cobble Enhancer is one example of a wet-look penetrating sealer. These types of penetrating sealers can achieve a wet look without a sheen and prevent the yellowing that occurs with some sealers.

The lack of a solid film over the surface means that penetrating sealers are more breathable. Air can pass through, carrying excess moisture with it. Anywhere that moisture underneath the pavers is a concern, such as pavers laid on a concrete foundation, can rely on penetrating sealers to prevent mold and mildew.

Penetrating sealers are a good choice in areas at high risk of chemical stains. They provide excellent protection against water, oil, and other contaminants. Driveway pavers can be protected against errant oil stains, as can concrete in a garage. Increased moisture resistance also makes them an excellent choice around pools and other water features.

It’s important to note that existing film-forming sealers must be stripped before applying a penetrating sealer. Any remaining film will prevent penetration, leaving inconsistent and splotchy results. However, some options can be applied over surfaces previously sealed with penetrating sealers if the previous application has worn away.

The Properties of Film-Forming Sealers

Film-forming sealers create a lasting barrier over the surface of the pavers. This opens the door to a wide range of finish and color options. Anything from matte to high-gloss is possible, depending on the specific sealer you choose.

Film-forming sealers rely on an array of different compounds — such as acrylic, polyurethane, and silicone — to create the seal. Each type differs in durability, cost, finish, and how well it stands up to specific challenges. However, they all have several characteristics in common.

The durable film layer provides significant protection against physical wear to pavers. Any abrasion or minor impact affects the film instead of the material underneath. They also create a barrier against water, oil, and other contaminants, although these substances can stain the film itself.

Drainage is a major consideration when dealing with any film-forming sealer. The film can block moisture entirely, which becomes problematic when water gets underneath pavers from the sides or below. This can lead to hazing of the sealer, with distinct patchy spots forming and affecting the appearance of the pavers.

To avoid these issues, film-forming sealers should only be used when materials are laid on a sand or bedrock foundation. This helps ensure proper drainage so that moisture doesn’t get trapped and affect the appearance and integrity of the pavers.

Cobble Coat H2O is one example of a water-based film-forming sealer that delivers excellent results. It provides a natural semi-gloss appearance and offers exceptional protection against UV light and physical wear. The low VOC - or low volatile organic compound — formula is eco-friendly and gives lasting protection for many different types of materials.

When to Use Which Type of Sealer

The use of concrete and other pavers around US homes has increased significantly over the past few years. Today, homeowners are taking advantage of pavers for countless applications. Driveways, patios, paths, pools, fire pits, and more feature pavers in or around them for a timeless and enduring style.

With so many potential projects coming your way, you need to be prepared to make the right choice of sealer in any situation. Both penetrating and film-forming sealers are possible options in a wide range of applications.

Natural Stone

Both penetrating sealers and film-forming sealers are potential options for natural stone. In general, film-forming sealers are often the better choice for tile and masonry surfaces that don’t present a porous surface, as penetrating sealers won’t be able to soak in effectively.

However, many types of stone pavers present porous surfaces ideally suited for penetrating sealers. In that case, the finish you want to achieve is one of the most important deciding factors. A high-gloss finish will require a film-forming sealer, while the most matte look will come from a penetrating sealer.

Brick and Clay Pavers

Brick and other clay pavers are an increasingly popular choice that provides a distinct look for driveways, paths, and more. Choosing the right type of sealer is essential to give lasting protection to that unique appearance.

Since brick is a highly porous material, penetrating sealers can be very effective. They provide the chemical stain protection needed for brick paver driveways, preventing oil stains from ruining such impressive work.

Penetrating sealers also provide a very natural appearance, which many homeowners want in brickwork. They want the material itself to come through rather than featuring a high-gloss finish. Penetrating sealers still provide plenty of versatility to adjust the desired appearance as well.

Concrete

Concrete is a versatile material with many different applications. The finish applied to the concrete during casting makes a significant impact on which type of sealer is most effective. Identifying the finish is vital to ensuring that you choose the right sealer.

Stamped concrete is a popular option for driveways, garden paths, and more. The stamping process creates the appearance of pavers or other shapes. Stamping can inhibit penetration, and most stamping applications call for a higher gloss, so film-forming is the best choice in this case.

Other types of concrete finishes that call for film-forming sealers include broom-finished concrete and exposed aggregate. These have intentionally rough surface textures and are often used on sidewalks and other high-traffic areas to improve traction. Film-forming sealers can protect these concrete applications.

Most concrete pavers are best suited for penetrating sealers. The same is true for smooth-troweled concrete and some examples of broom-finished concrete. The penetrating sealer can provide lasting protection for the porous concrete pavers and deliver a natural appearance.

Travertine Stone

Travertine stone and other types of limestone and marble are very popular options around pools, patios, and other outdoor living areas. They have to stand up to water, spills, and plenty of traffic. Sealers can ensure that they stand the test of time and bring out a beautiful finish as well.

Both penetrating and film-forming sealers may be appropriate for travertine stone in different applications. Since the stone is porous, penetrating sealers can provide lasting protection against moisture and contaminants.

Around a pool or patio, a film-forming sealer may be the best option. They provide additional protection against moisture penetrating from the surface, along with exceptional UV protection in sunny areas. Keep in mind that film-forming sealers shouldn’t be used if your stone is laid over concrete.

Penetrating sealers can provide a more matte appearance for travertine stone in various hardscape elements and deliver exceptional stain resistance. They will also help avoid the uneven physical wear that film-forming sealers can develop in high-traffic areas such as walkways or stairs. 

Sealers for Any Material or Application

Whether you’re looking for penetrating or film-forming sealers, Surface Logix provides a comprehensive variety of options alongside service that you can count on. Find the specific products you need and enjoy a fast turnaround to maintain your stock when you need it most. Get your quote from Surface Logix today.