After over 30 hours of researching more than 60 concrete sealers and testing and evaluating seven of them, our results are found below. We found that the Siloxa-Tek 8500 is best for most people. Its made of high quality silanes and siloxanes with a 40 percent solids content, so it’s active ingredients are stronger, less watered down and approved by the Department of Transportation. The 8500 sealer leaves a natural finish without any artificial luster or sheen leaving a natural, protected surface without ever fading.
Why you should trust us
We have worked in the construction industry for more than 20 years. We’ve reviewed countless sealer products with our conclusions posted throughout this site. For this guide we also talked to a number of experts about what they look for when sealing any concrete application.
The American Concrete Institute provided us with resources about terminology and the industry, and we gained insight from magazines such as Concrete Decor, Concrete Construction and For Construction Pros as to which products were popular among contractors.
To determine the longevity of sealers we relied heavily on customer reviews from Home Depot, Lowes and Amazon.
The difference between penetrating sealers, decorative coating and durable coatings
If you’re purchasing a concrete sealer for the first time or you’re due to reapply, its helpful to know the meaning behind some basic terms – including penetrating sealer, decorative coating and durable coating to ensure you get the appropriate product.
Penetrating sealers: Penetrating sealers penetrate into the concrete to form a chemical barrier that protects against water, moisture and deicing salts. They usually leave a natural finish without changing the surface appearance and most products are breathable allowing for vapors to escape. They are more frequently used in exterior applications to protect against the harsh elements. A penetrating sealer is your best choice if you are looking to protect your application from deicing salts, freeze-thaw cycles and water without changing the surface appearance or feel of the concrete. A penetrating sealer has a long lifespan and typically requires reapplication after five plus years of service life.
Decorative coatings: Decorative coatings are typically of an acrylic chemistry available in both solvent and water based formulations. Available in a range of sheen levels they typically leave a satin or gloss finish changing the look, feel and texture of the concrete. They are great for enhancing colors and giving concrete the much desired wet look. Acrylics generally wear faster than penetrating sealers and usually require reapplication much sooner, typically every year if exposed to deicing salts. Decorative acrylic coatings are great at first leaving the concrete looking nice but tend to wear quickly and cost more in the long run with constant reapplication.
Durable coatings: Durable coatings build a protective film on the concrete surface, producing a hard, long-lasting abrasion and chemical resistant finish. Available in a variety of colors most durable coatings leave a gloss finish. Durable coatings are harder and last longer than decorative coatings. Because durable coatings may yellow with exposure to UV radiation they are limited to interior use.
How we picked and tested
Manufacturers offer penetrating sealers, decorative coatings and durable coatings but we’ve focused our selection on penetrating sealers due to their longevity, versatility, appearance and practicality.
Our testers were drawn to the natural finish of penetrating sealers. We aren’t alone in that assessment, as many of our experts agree. A Concrete Decor article titled, “Use of Penetrating Sealers is on the Rise” published in January of 2017 states, “The decorative industry grew up on the “one size fits all” high-gloss sealer which was the go-to coating for decades. While high gloss is still widely used, low-gloss and natural finishes in the decorative concrete industry have been gaining momentum as homeowners, architects and designers seek more ecofriendly, green and natural-looking sealing options.”
Aside from its appearance, penetrating sealers offer greater durability and are less prone to water absorption and deicing salt damage than decorative coatings.
Ultimately you want a sealer that provides water repellency to keep out any salts, mold/mildew, efflorescence and dirt, and will have a long life span. We found that in penetrating sealers with a silane/siloxane chemistry.
In our research, we found that more inexpensive penetrating sealers suffered in quality due to low solids content and most commercial products were exorbitantly priced. We prioritized finding a high quality sealer that was both durable and had a high solids content at a reasonable price.
According to our experts, the best penetrating concrete sealers are resistant to water, chloride absorption and staining but clear enough to not change the look or feel of the concrete. The Concrete Decor article mentioned above states, “While relatively new to the decorative industry, penetrating sealers have been used successfully in other markets for decades. Originally developed for the stone, masonry and concrete flatwork industry, penetrating sealers primarily resist water and stains, while not changing the substrate’s appearance. Their primary functions have been salt and acid resistance, efflorescence control and water resistance.”
Concrete Construction noted that, “When applied properly, penetrating sealers can serve as chloride screens and dampproofing to improve durability against destructive corrosion of embedded reinforcement and damage from freezing and thawing.”
Decorative sealers can be beautiful to look at but they’re also more likely to fade over time. For this reason we limited our search to products with a natural finish that do not need to be reapplied as frequently.
Overall we preferred sealers with proven longevity that were highly reviewed with excellent water beading characteristics.
We searched for sealers that are available online which allows the consumer freedom to order and have them shipped to a home or business versus having to shop around and find a distributor that carries the product in stock. Ideally we wanted sealers that were not only conveniently available but offered excellent performance. At the very minimum we felt each sealer should be composed of a 20% silane/siloxane chemistry. We were able to rule out any sealers that were too watered down or did not have enough active ingredients. Sealers that offered additional oil and stain repellency were viewed as a nice bonus, but were not a required factor in our selection.
A note on penetrating sealers. Though plenty of penetrating sealers are available our research showed that homeowners often regret purchasing a penetrating sealer that did not offer any sort of water repellency, such as a penetrating silicate densifier. These sealers simply harden the concrete but offer no water and stain repellency. They are inexpensive, but likewise they don’t offer the full benefits of a silane/siloxane penetrating sealer. Because of this we prioritized finding products that were penetrating and hydrophobic impregnating sealers.
After considering over 60 concrete sealing products, we evaluated and tested seven. We applied and examined each product to check for a clear, natural finish. We tested for abrasions, salt exposure and water absorption and we also compared the application techniques for ease of use. Finally we asked testers to check for mold, mildew growth and efflorescence deposits.
Our pick: Our testers like the ease of use and lack of maintenance of the Siloxa-Tek 8500 of all the sealers we tried. The product is easy enough to use so a professional is not needed to apply it. The Siloxa-Tek 8500 is also available as a concentrate which was lacking from the other sealers we tested. The type of silane, one of the chemical components, that is used in the product also gives the Siloxa-Tek 8500 a longer performance life, making it more stable and less volatile.
The sealer not only uses quality silanes (octyltriethoxysilane) but it is a well formulated blend of silane and siloxane. Water was not absorbed by the concrete whatsoever during the water absorption test; in fact we were able to move the beaded water across the concrete and even then it was not absorbed.
Also the sealer is available in a ready to use or concentrate version so you have the freedom to choose if you want to pay less to do a little extra work or pay a little more for the ease of convenience. The concentrate allows you to pay less in shipping since a one gallon of concentrate will make a five gallon pail of sealer, which wasn’t a possibility with some of the other sealers we looked at. This sealer is sold through Home Depot Lowes and Amazon, and Ghostshield is a brand that’s been around for years.
Flaws but not deal breakers
The only drawback to the Siloxa-Tek 8500 is that it does not repel stains such as oil and grease. We detected these minor imperfections when the Siloxa-Tek 8500 was applied to a garage floor. Some of our testers found that if you prefer stain protection the 8500’s counterpart, the Siloxa-Tek 8505, is resistant to staining. Also the Siloxa-Tek 8500 is more expensive than some of the other sealers we reviewed, but the quality and longevity were unsurpassed making it a worthwhile investment.
Long-term test notes
After fifteen months of exposure to the elements, two freeze-thaw cycles and two winter seasons, we still highly recommend it. We did not have any visible cracking, spalling or deicing salt damage on driveway applications. Though we haven’t tested the product for a full five to ten years like the manufacturer claims it will work for, we haven’t experienced any major issues ourselves but we’ll continue to long-term test to see if any problems arise.
Though we like the Siloxa-Tek 8500 best, if you prefer something less expensive and a product that is available on store shelves we recommend Rustoleum Okon S-40. This sealer is also a 40% silane/siloxane, penetrating sealer. It is not available concentrated, but it has a nice price point for a 40% formula. This sealer comes with the option to purchase online or in some retail store outlets.
The S-40 has proven longevity, with one reviewer on the Home Depot site saying “This product is 40% silane/siloxane and is the best deal on an active ingredient basis. Most of the other products out there are just watered down versions with only 5%-20% active ingredients. S-20 was the next best deal I could find. Be sure to look at the concentration of ingredients on the Spec sheet so that you don’t end up just buying water.” We’re confident this will remain an effective and viable option for sealing concrete for years to come.
Eagle Natural Seal had a lesser active ingredient content than our other picks but there is no denying its cost effective price point. Ultimately most of our testers found the sealer to be a easy to apply solution though it did not produce as significant of a water bead effect as some of the other products we tested.