Exposed aggregate concrete is a great way to increase your curb appeal, but it comes with its downfalls as well. Since exposed aggregate isn’t as durable as solid concrete, it’s important to choose the right type of concrete sealer to maintain its quality.
If your main goal is increasing the durability and the longevity of your exposed aggregate concrete a water-repellent penetrating sealer is recommended. If enhanced appearance is most important to you, choosing an acrylic concrete sealer is the best choice for your project.
To find out more about the different types of concrete sealers that can be used on exposed aggregate, continue reading below. We’ve also provided a handy guide that explains the different factors to consider while selecting a concrete sealer.
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Which Type of Sealer Is Best for Exposed Aggregate?
There are many different types of concrete sealer on the market, but not all of them are ideal for exposed aggregate. Since exposed aggregate is concrete with the top layer removed to expose the rocks underneath, it’s not as strong and durable as solid concrete is. Therefore, it has different needs when it comes to concrete sealer. Below, you’ll find brief descriptions of common sealers and their uses.
Penetrating Sealers
Rather than sitting on top of the surface of the concrete, penetrating sealers soak into the concrete’s pores. A chemical reaction between the sealer and the concrete forms a barrier against moisture and other contaminants. Since penetrating sealers soak into the concrete rather than forming a layer on top, penetrating sealers don’t have any effect on the concrete’s appearance. They are the most long-lasting type of sealer and only need to be replaced every five to ten years. However, some types of penetrating sealers can last as long as 25 years!
One thing to note is that penetrating sealers will not secure loose stones in the exposed aggregate. This type of sealer is great for preserving and protecting the concrete, but if your goal is to keep stones from coming loose, an acrylic sealer may be the better choice.
Read on for further explanation of the various types of penetrating sealers. Each has its own strengths and intended purposes, so be sure to consider whether they match with your own goals for your exposed aggregate.
Silane
In comparison to the other types of penetrating concrete sealers, silane is the most durable and can last up to 25 years without needing to be resealed. It adds protection from the elements as well as long-lasting sturdiness to your concrete.
Silicate
The main benefit that silicate provides is increased concrete surface strength. However, silicate isn’t typically recommended for exposed aggregate. Instead, it’s best used on polished concrete surfaces. While it’s not quite as durable as silane, you can still get 15 to 25 years out of the sealer before having to reseal.
Siliconate
Siliconate has a similar lifetime to silicate, lasting 10 to 25 years on average before needing to be resealed. This type of penetrating sealer is great for blocking out moisture. It’s also used to cure new concrete.
Siloxane
If you’re interested in a happy medium between penetrating sealers and acrylic sealers, siloxane may be a good choice for you. While it is a penetrating sealer, it doesn’t soak into the concrete’s surface as deeply as the other penetrating sealers do. For this reason, it must be resealed every three to five years.
Acrylic Sealers
Unlike penetrating sealers, acrylic sealers sit on top of the concrete, forming a thin layer that enhances and protects the exposed aggregate. Since this type of sealer is topical, it can hold loose stones in place and prevent stones from coming loose as well. It also reduces pitting and extends the exposed aggregate’s lifetime while preventing dusting, staining, and deterioration.
Something to note is that acrylic sealers must be replaced far more often than penetrating sealers do. You should plan on resealing your exposed aggregate every one to three years in order to properly maintain and protect the concrete. For this reason, it’s great to choose a recoatable sealer.
When selecting an acrylic sealer, stay away from styrene acrylic, which has a tendency to turn yellow with exposure to sunlight. Instead, select a sealer that offers UV protection and repels water, oil, grease, and stains.
Acrylic concrete sealers come in two main variations: water-based and solvent-based. Learn more about the characteristics of each sealer below.
Water-Based Acrylic
One of the biggest advantages of water-based acrylic concrete sealer is that it’s environmentally friendly and doesn’t contain harmful chemicals. There are less risks associated with the application and use of water-based acrylics. This type of sealer gives a high-gloss finish and enhances the exposed aggregate’s appearance without changing its color.
Solvent-Based Acrylic
If you’re looking for color, a solvent-based acrylic is your best choice. Solvent-based acrylic concrete sealers come in a wide range of different shades, so you can select the one that looks best on your exposed aggregate. Solvent-based acrylics are often used for driveways and truly enhance the appearance of the concrete. They also come in clear, high-gloss formulations that don’t add color to the concrete.
Epoxy
Epoxy generally comes at a much higher price than acrylic and penetrating sealers. However, a higher price point doesn’t necessarily mean that epoxy is suited to your particular concrete project. Epoxy is much more dense than acrylic sealers, and it forms a thick layer on top of the surface of the concrete.
Epoxy tends to be extremely slippery, especially when wet. Because exposed aggregate has great traction to begin with, epoxy won’t make it quite as slippery as it would make solid concrete. However, the slipperiness factor is certainly something to keep in mind when deciding on the type of sealer you’d like to use for your exposed aggregate.
Factors to Consider When Selecting an Exposed Aggregate Sealer
Making a decision between the various types of exposed aggregate concrete sealer can be overwhelming if you don’t know exactly what you’re looking for. Keep the following criteria in mind when evaluating potential sealers for your exposed aggregate.
Durability
First, consider how often you’re willing to do maintenance on your concrete sealer. If you’d prefer not to deal with resealing your exposed aggregate for as long as possible, a penetrating sealer is a great choice. However, if resealing your concrete every few years isn’t a dealbreaker for you, you might find that acrylic concrete sealers are a better pick.
Safety
The safety aspect of a concrete sealer involves two main issues: application and slipperiness. As far as application goes, you’ll want to determine whether or not your concrete sealer contains potentially dangerous chemicals. If so, you’ll need to take precautions while applying it. You’ll also need to question how slippery the sealer will make your exposed aggregate, because slippery concrete can be dangerous.
Appearance
Of course, the finished look that you’re in search of plays a huge role in your sealer decision. If you don’t really want to change the look of your exposed aggregate, then a penetrating sealer is perfect for you. For a glossy layer on the top of the exposed aggregate, a water-based acrylic concrete sealer will do the trick. But for a complete concrete color change, you’ll need to use a solvent-based acrylic sealer.
Frequently Asked Questions
What will happen if I don’t seal my exposed aggregate?
The exposed aggregate may crack, crumble, and develop blemishes over time, and its lifetime will be greatly shortened. Its initial high-quality appearance will quickly fade.
How do you apply sealer to exposed aggregate?
First, you must clean the exposed aggregate by using a pressure washer, rust remover, and degreaser. Then allow it to dry fully before moving on to the sealer application. You’ll want to use a half-inch roller and pump-up sprayer to evenly coat the exposed aggregate. Allow it to dry for a few hours before walking on the concrete, and avoid driving on it for 24 to 48 hours.
