Topical vs Penetrating Stone Sealers: What’s the difference?

The popularity of natural stone countertops, floors, showers, and fireplaces has exploded in recent years. Along with its popularity, more products are available to protect this beautiful investment.

Although natural stone is a durable material, it is not completely maintenance-free.

Spills, dirt, and grime can all lead to stains and other damage if not properly sealed and protected.

Therefore, it is important to protect your investment from the elements by sealing it with a quality stone sealer.

A stone sealer is essentially a product that protects the stone from damage by forming a barrier against spills and other potential stains.

A properly applied sealing not only protects the stone from water, oil, and dirt, but also from potential physical damage such as chipping and scratches. It also forms an invisible barrier between the porous stone and any liquid, making spill cleanup easier.

Almost all types of natural stone need to be sealed, but the frequency of re-sealing will depend on the type of stone, its porosity, and the amount of traffic it receives.

Granite, marble, limestone, slate, and other types of stone that have a high degree of porosity should be sealed more often than denser stones such as quartzite and soapstone.

But essentially, any natural stone can and should be sealed to protect it from damage.

Before we delve any further, it is always best to consult with the manufacturer or supplier of your stone to get their specific recommendations on sealing products and frequency. They will be able to give you the best advice for your particular situation.

In fact, if you are going to have natural stone installed in your home, it is a good idea to bargain with the installer to include the cost of a quality sealer in the overall price.

This will save you money in the long run and give you peace of mind knowing that your stone is properly protected.

There are two main types of stone sealers available on the market: topical sealers and penetrating sealers. They are both effective in their own way but differ in terms of durability, ease of application, and breathability.

A topical sealer is a coating that stays on the surface of the stone and forms a barrier between the stone and any potential spills. It is usually made of acrylic, polyurethane, or silicone and needs to be reapplied once or twice a year.

A penetrating sealer, on the other hand, penetrates deep into the pores of the stone and bonds with it chemically. This type of sealer does not change the appearance of the stone and does not need to be reapplied as often as a topical sealer.

What are topical (finishing) sealers?

Topical sealers form a protective layer on the surface of your stone. They’re typically made from acrylics, polyurethanes, or silicones, and they provide good protection against water and stains.

However, because they sit on top of the stone, they can eventually wear away or become peeled. They also require more frequent reapplication, typically once or twice a year.

Here are the most common types of topical sealers:

Acrylics

Acrylic sealers are the most popular type of topical sealers. They’re easy to apply, have a high level of protection, and don’t change the appearance of the stone. These sealers are available both as water-based and solvent-based products.

Water-based acrylics are the most common type. They’re less smelly and easier to clean up than solvent-based options, but they don’t last as long.

Solvent-based acrylics have a stronger smell, but they’re more durable and provide better protection.

Acrylics aren’t the longest-lasting topical coating sealers, but they’re a good option for lower-traffic areas. They can be paired with a sacrificial coating, like wax, for added protection.

Polyurethanes

Polyurethane sealers provide good protection against water, stains, and abrasion. They form a coating that is more durable than acrylic and lacquer sealers. They are also more resistant to scuffs and discoloration.

These sealers might be difficult to apply because they must be properly mixed before they can be used. They are available in a variety of sheen levels and will produce a clear, non-yellowing surface.

Silicones

Silicones are the most durable type of topical sealer and provide excellent protection against water and stains. However, they’re also the most difficult to apply and can make the stone slippery.

Epoxies

An epoxy sealer will provide you with a long-lasting, abrasion-resistant finish that is also water repellent. However, water will not be able to escape from the concrete, thus you may experience troubles with retained moisture.

Before pouring the epoxy, the surface must be completely dry. If there is any moisture present, the epoxy will not adhere properly and will eventually fail. Thus, using a moisture barrier like a polyethylene sheet is recommended.

Because epoxy sealers are yellowing under UV light, they are not recommended for outdoor use. They can also be difficult to apply because they require a two-part system that must be properly mixed.

There are clear and colorful epoxy variants available. In any case, you get a glossy finish that can withstand heavy foot traffic.

Lacquers

Lacquers are typically used as a top coat over another sealer to provide an added layer of protection. They’re also used on their own in lower-traffic areas.

Lacquers are available in a variety of sheen levels, from glossy to matte. They’re typically clear, but colored lacquers are also available.

Because lacquers sit on top of the stone, they can eventually wear away or become peeled. They also require more frequent reapplication, typically twice a year or more.

Lacquer can be applied on precast concrete blocks or pavers to give them a smooth, shining appearance that is both long-lasting and eye-catching.

There is a protective layer of lacquer that shields the surface from dust, abrasion, and water as well as UV radiation.

Pavers and concrete can be given a “wet” appearance by lacquering them. There are lacquer formulas for both the interior and exterior of a building.

Waxes

Waxes are commonly used as a top coat over another sealer to add an extra layer of protection. They can also be used on their own, but they will need to be reapplied more frequently.

There are both natural and synthetic waxes available. Natural waxes, like carnauba wax, provide good protection but need to be reapplied more often.

Synthetic waxes, like polymer waxes, last longer but don’t provide as much protection.

Waxes can be applied by hand or with a machine. If you’re using a machine, make sure to use a low-speed setting to avoid damaging the surface. The secret to a good wax job is to apply thin, even coats and buff the surface after each coat.

What are penetrating (impregnating) sealers?

Penetrating (impregnating) sealers sink into the pores of your stone, creating an invisible barrier that protects it from within.

They’re typically made from siloxanes or silanes, and they provide long-lasting protection against water and stains.

However, because they penetrate into the stone, they can be difficult to remove if you ever need to reseal your stone. Penetrating sealers typically only need to be applied every few years.

Here are the most common types of penetrating sealers:

Silanes

Silane sealers are composed of tiny silicone molecules. Because these molecules are tiny in size, they may penetrate deeply into the pores of your material, resulting in a strong connection, great water repellence, abrasion resistance, and a long lifetime.

Silane sealers will only deteriorate if the surface of your stone, pavers, or concrete decays.

Siloxanes

Siloxane sealers are composed of larger silicone molecules. They have all the great benefits of silane sealers, but they don’t penetrate as deeply into the pores of your stone.

As a result, they might not last as long as silane sealers, but they’re still an excellent choice for protecting your stone.

Fluoropolymers

Fluoropolymer sealers are a newer type of penetrating sealer. They’re composed of fluorine and carbon molecules, and they provide long-lasting protection against water, stains, and dirt.

Fluoropolymer sealers are more expensive than other types of penetrating sealers, but they’re also more durable.

How do topical and penetrating sealers differ?

We have already explained what topical and penetrating sealers are, but it is worth mentioning the main differences between these two types of sealers.

Application depth

Application depth is the primary difference between topical and penetrating sealers.

Topical sealers form a coating on the surface of the stone that can range from very thin to quite thick, while penetrating sealers sink into the pores of the stone to form a barrier.

Appearance

Because topical sealers form a coating on the surface of the stone, they can change its appearance.

Topical sealers typically offer a satin or gloss finish while penetrating sealers sink into the pores of your stone and don’t change the surface appearance.

So your stone will look the same as it did before you applied the penetrating sealer which is typically matte or natural looking.

Used Materials

Topical sealers are typically made from acrylics, polyurethanes, silicones, or lacquers. Penetrating sealers are typically made from silanes, siloxanes, or fluoropolymers.

Breathing Quality

Penetrating sealers offer better “breathing quality” than topical sealers. This means that they allow your stone to release moisture vapor while still protecting it from water and stains.

Topical sealers, on the other hand, can trap moisture vapor beneath the surface of your stone which can lead to problems like efflorescence (salt buildup) or even mold and mildew growth.

Protection

Both topical and penetrating sealers offer excellent protection against water and stains. However, because penetrating sealers sink into the pores of your stone, they typically offer better protection than topical sealers.

That said, the protection offered by a topical sealer can be increased by reapplying the sealer on a regular basis.

Durability

Both topical and penetrating sealers are quite durable. However, because penetrating sealers sink into the pores of your stone, they typically last longer than topical sealers.

Topical sealers will eventually wear away while penetrating sealers will last for many years.

That is why penetrating sealers are typically only applied every few years while topical sealers may need to be applied yearly or quarterly depending on the type of stone and the amount of traffic it gets.

Surfaces slipperiness

One of the main disadvantages of topical sealers is that they can make your stone surface very slippery when wet. That is why it is important to choose a topical sealer that is specifically designed for use on stone.

Penetrating sealers, on the other hand, do not make your stone surface slippery when wet. This can be a critical consideration if your stone is used in an area where it might get wet, such as a shower or pool deck.

Uses

Topical sealers are typically used on concrete and pavers while penetrating sealers are typically used on natural stone.

The reason for this is that concrete and pavers are very porous and need the added protection that a topical sealer can provide.

Natural stone, on the other hand, is less porous and can be protected with a penetrating sealer. That said, both types of sealers can be used on any type of stone.

UV resistance

Topical sealers typically offer better UV resistance than penetrating sealers. This is because they form a coating on the surface of the stone that protects it from the sun’s rays.

Penetrating sealers, on the other hand, do not form a coating on the surface of the stone and therefore do not offer as much UV protection.

Conclusion

So, which type of sealer should you choose? It really depends on your needs. If you’re looking for a sealer that will provide long-lasting protection with minimal effort, then a penetrating sealer is the way to go.

However, if you’re looking for a sealer that will change the appearance of your stone or provide a surface barrier against water and stains, then a topical sealer is the better choice.