Maintaining Durability with Concrete Sealing

Written by Diane Calabrese | Published July 2024

Crumble as in cakes is delicious. Crumble paired with concrete is devastating. Yet with freeze and thaw cycles, is there anything that can be done to maintain the durability of concrete? Yes, there is.

Sealing prevents water from seeping into the porous aggregate. That means there’s no water—or at least minimal water—to expand into ice and thaw.

What about coating? Does it differ from sealing?

“When you seal concrete, you’re applying a protective layer to it,” says Missy Ordiway, business development manager at Deco Products Inc. in Denver, CO. “This layer helps prevent things like water or stains from seeping into the concrete. It’s like giving the concrete a shield to keep it safe and strong.

“On the other hand, coating concrete involves putting a layer on top of it. It’s like an additional layer of protection; this can change the appearance, not only provide additional protection,” continues Ordiway. “You can use a penetrating sealer to seal your concrete or a topical sealer to coat your concrete.”

Ordiway cautions that as with all good outcomes, ensuring concrete reaches its full lifespan requires a match between method and substrate. The optimal outcome also requires proper maintenance that includes reapplication at appropriate intervals.

Where do you start to get it right?

“Upon initial installation make sure you follow the manufacturer’s instructions on how to apply the sealer,” says Ordiway. “Fix any issues right away so they don’t become bigger ones down the road.”

And don’t allow soiling to accumulate. “Regularly clean the concrete surface to remove dirt, grime, and stains,” says Ordiway. “This helps the seal or coat stay strong. Reapply sealer as needed, typically every two to three years.”

MORE THAN SEMANTICS

Let’s go a bit deeper into the difference between a sealant and a coating. “Sealants are a subcategory of coatings,” says Joseph Daniel, CEO of ITD Chemical in Tucker, GA.

“Every sealant is a coating, but not every coating is a sealant,” explains Daniel. “The most obvious example that is familiar to a consumer would be to highlight the difference between sealing a deck and painting a deck.”

The sealant, in short, goes deep. “The wood sealer penetrates into the fibers of the wood to ensure no moisture is able to penetrate following the application, whereas paint is a coating that sits on top of the wood,” says Daniel.

The result with concrete is analogous to the one described for wood. “The same difference is relevant in concrete or paver sealing, whereby a sealer is a penetrating product, and a paint or coating product is a surfacelevel product,” says Daniel.

Given the different grades of concrete, and the differences that come because of regulatory constraints on coal ash use and more, are there concerns about how sealers perform on different substrates? “In general, concrete and other similar aggregate materials behave similarly when it comes to sealers,” says Daniel.

“More important than the aggregate type is to establish what the goal of the sealing process is,” says Daniel. “If it’s purely functional, there are sealers that have no decorative appeal by design, including our company’s One Seal; whereas if a glossy, shiny look is desired, there are products that will give the consumer that result—including our company’s Clear Seal.”

Daniel endorses sealing because of the multiple benefits it brings. “Sealing lower-quality aggregate materials can absolutely improve the lifespan and durability of the product,” says Daniel. “Sealing the concrete prevents penetration of moisture into the pores, which reduces cracking and combats freeze-thaw cycles, among other processes that weaken concrete.”

CANINES (AND MORE) IN MIND

Dog lovers know the inevitable heart tugging that occurs when dropping off a pet even for the shortest kennel stay. A clean kennel that is toxin-free is a top concern.

Biodegradable sealers for concrete floors in kennels are among the products offered by SealGreen—ReUse

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Concrete Sealing Specialists LLC in Overland Park, KS. The CEO of that company responded to many questions from us after consulting with his team. Here’s some of what he told us about the ins and outs of concrete sealers.

Begin with maintenance of concrete substrates. Proper maintenance requires the use of detergent, not power washing with a pressure washer alone.

“Pressure washing removes surface dirt but does not remove dirt and dust embedded in the pores of the concrete,” says Hernandez. “The more open the pores of the concrete, the better seal you will get regardless of whether you use a topical coating or a penetrating sealer. We consider this a requirement for a good application.”

Hernandez and his team emphasize the importance of the cleaning, pressure washer plus detergent. And it’s a recommendation that power washing contractors can certainly amplify when discussing the importance of cleaning and sealing with their clients.

And for those of us concerned— from our own experiences with concrete walks, drives, shed bases, etc.— about the effect of regulations on the durability of concrete, Hernandez provides a little context. “Sealing the concrete is always recommended no matter if you have fly ash [coal ash] or not,” says Hernandez.

One way to think of sealing is that it provides something of a defensive line against the vagaries of weather. Whimsical weather events are inevitable. Sealing is a choice, and a good one. The less weather impacts the concrete, the better and longer it lasts.

“Fly ash improves the workability, strength, and durability of concrete,” explains Hernandez. “It also reduces the amount of Portland cement required.” [Reminder: Portland cement serves as the binder for aggregate. Bound aggregate is concrete. Although often used interchangeably, concrete and cement are distinct entities. The composition of Portland cement is

usually lime, silica, iron, alumina, and magnesia.]

Hernandez says that fly-ash concrete affords a list of benefits. These are “reduced segregation; improved cohesiveness; reduced rock pockets, air voids, and bug holes; higher strength over time; and increased durability.”

Although some of us may be thinking quite locally, shaking our heads over the crumbling of a shed floor, Hernandez reminds us that the importance of sealing goes well beyond our domiciles. And he emphasizes that sealing is specific to the purpose of the concrete.

“Residential concrete for driveways, basement floors and walls, and porches and patios should always be sealed in order to reduce damage to the substrate and to lengthen the life of the concrete,” says Hernandez. The process begins with an evaluation of the type of sealer that will achieve the desired effect.

“Commercial uses of concrete such as bridges, streets, containers, etc. will require much more high-end sealers and should be evaluated and applied by people who are experts in the area,” says Hernandez. “However, it is my opinion that all concrete should always be sealed.”

Hernandez reflects upon a few examples from the commercial sector. “If you are sealing a bridge, you want to get as much penetration into the concrete as possible,” he explains. “That includes the deck, top, underdeck area, bottom, and all vertical columns, walls, etc.”

And a second example from Hernandez: “Basement walls should be sealed outside with a sealer that waterproofs the concrete versus the inside where a regular sealer will do,” he says.

“And a final example,” says Hernandez. “A road or a driveway needs to be sealed on the surface. Depending on the traffic volume and depth of the concrete, the appropriate sealer is necessary to obtain the best penetration and durability against the daily traffic.”

BEYOND FREEZE-THAW

The most immediate concern regarding concrete may be the potential damage from seeping and then freezing and thawing of water. But keep in mind that sealers can also do more than thwart water.

“Sealers also protect from surface damage, corrosion, and staining,” says Hernandez. Thus, contractors working even in the driest regions should be talking to their customers about the benefits of sealing.

Hernandez elaborates a bit on the difference between topical and penetrating sealers. A topical sealer “coats” and thus creates “an impermeable layer and prevents moisture, stains, etc. from penetrating the concrete,” he explains.

Here’s what to keep in mind about topical sealers. Applied only to the surface, they are more vulnerable to damage, wear and tear, weather, and UV rays, explains Hernandez, who likens them to fingernail polish because

they can be made more decorative by adding color or texture.

But like nail polish, concrete coatings “wear off and need regularly scheduled maintenance,” not only to stay attractive but also to protect against moisture penetration. If a coating makes concrete slick, an anti-skid product may be needed, says Hernandez.

“Penetrating sealers are also known as reactive sealers,” says Hernandez. “These sealers can penetrate into the substrate and can react chemically with the concrete, creating a gel which hardens and bonds to the concrete. This reaction fills the pores and blocks penetration of moisture.”

Hernandez puts the lifespan of topical sealers—coats—at one to three years, while penetrating sealers have a lifespan of five years or longer. Once penetrating sealer is properly applied, the prognosis is good. “Maintenance is usually an inexpensive, easily done reapplication with minimal downtime .”