Sealing your concrete driveway (or garage) is a wise investment that can add years of service-life by reducing cracks and corrosion caused by water, moisture and deicing salts. Using a penetrating sealer will do the trick, but what about protection from oil or transmission fluid? Let's shed some light on this topic...

Someone once said, “Life was simple when Apple and Blackberry were just fruits”. It is true that advancements in modern technology bring lots of good. However, sometimes these new technologies aren’t new technologies at all. They are just deceptive marketing terms designed to sell you a product, making things very confusing.

Information is published and passed around so quickly these days. It seems almost impossible to find the time necessary to research and find out if what you are reading is actually true. “Fake news” is the new norm. In a world filled with sound bites and bullet points, how do we get to the bottom of it?


Do yourself a “solid” and spend time to educate yourself on the basics. Do the research because it will pay dividends for you; especially when it comes to choosing where to spend your hard-earned cash. Don’t let the carefully crafted bullet points lead you down the wrong path.

When it comes to choosing an oil repellent concrete sealer, there’s no shortage of industry jargon and anyone looking to protect their concrete from oil stains are going to be faced with terms like: “Penetrating”, “Film-Forming”, “Water-based”, “Solvent-based”, “Silane, Siloxane or Silicate”, ”Fluorinated” and “Oil-repel vs. Oil-resist”... the list of jargon seems endless. What do these terms mean? The goal of this article is to give them meaning so you can make an informed decision.

Penetrating vs. Film Forming Sealers.

Like our skin, concrete and natural stone surfaces contain pores where particles and foreign substances like water, dirt, oil and salt can be easily absorbed. These particles can be detrimental to the long-term beauty and the integrity of the substrate. Staining, pitting, spalling and freeze-thaw cracking can lead to expensive repair or even complete replacement.

Film forming sealers create a protective film on the surface to protect it from moisture, abrasion, wear and tear. They are also known as topical or surface sealers. They bring out the beauty of the surface by enhancing and darkening colors with a gloss or semi-gloss finish. They prevent the absorption of dirt, oil and grease while making it easier to clean and maintain. However, film forming sealers change the properties of the surface and tend to be slippery when wet. They are also prone to cracking, wearing, or delamination and are known to trap moisture inside the concrete. There are three (3) main types of film-forming concrete sealers; Acrylic, Urethanes, and Epoxies.

Penetrating sealers (or impregnating sealers) can prevent damage and stains by holding liquids on top of the surface. They make concrete resistant to the absorption of organic materials like dirt, water, oil and salt while still allowing the surface to breath. They work by creating a chemical reaction below the surface, dramatically reducing the ability of the concrete to absorb foreign matter. Staining, freeze-thaw damage, efflorescence, salt and acid attacks are all related to the tendency of a substrate to absorb molecules of liquid. Impregnating sealers penetrate below and leave surfaces completely unchanged, non-slip and natural. There are many different variations available and learning how a penetrating sealer works will help you decide which one is right for you.

Continue reading to learn more.

Water-Based vs. solvent-based. Which is right for me?

Penetrating concrete sealers come in both water-based and solvent-based formulations. Both formulations penetrate into the concrete and work in the same manner, but it is important to note that when discussing water or solvent, we are discussing the “carrier” of the active ingredients within the sealer. We will get into “active ingredients” later on, so hold tight. For now, let’s talk about these two carriers.

All of us remember the chemical makeup of water from science class. H20 means that each molecule of water contains two (2) hydrogen atoms and (1) oxygen atom. They are connected by covalent bonds, making water a short simple chain of atoms that are highly attracted to each other. This attraction creates a very high level of tension and why it is so difficult to separate water into smaller molecules (think water beading effect). Water-based formulations tend to sit on top of porous surfaces. As a carrier, water tends to be the most cost-effective solution because it’s readily available. It dries fast, is non-flammable, non-hazardous and is safe to use around people and pets.

Solvent molecules are bit more complex. Solvent molecules contain multiple hydrogen, oxygen, and carbon atoms. This longer chain of atoms greatly reduces the covalent bond (or strong attraction to each other). Lower tension levels will allow for solvent molecules to break apart easily. Solvents penetrate in situations where water molecules would stick together and sit on top of the surface. As a carrier, solvents will carry active ingredients deeper into dense surfaces like concrete. Solvents include toluene, xylene, acetone, and mineral spirit (just to name a few). They are typically more expensive, take longer to dry, and have higher levels of VOC (volatile organic compounds). Volatile organic compounds (VOCs) can be harmful to the environment. This a popular topic and is largely due to the increasing restrictive regulations across the country requiring lower VOC levels in various paint and coatings. VOC regulations vary from state-to-state. If you are looking for the performance of a solvent and prefer to avoid VOCs, there are low VOC solvents available. “Low VOC” is usually indicated somewhere on the product label. Keep your eye out when choosing.

In summary; Water is safer, while solvents penetrate deeper. Low VOC solvents are available.

What is silane and what is siloxane?

Silanes and Siloxanes are considered the “active ingredients” within the sealer. They work independently and in conjunction with the substrate. Their job is to penetrate deep into the concrete, sealing it from the inside by reacting with the material makeup of the concrete. They work by reducing the absorption of rain, water, snow, moisture, chlorides, and road salt.

Silane is an inorganic chemical compound that is highly reactive. There are different types of silanes, but a silane is a compound of four (4) atoms connected to one (1) silicon atom. Silane is usually the smallest molecular compound found in commonly available penetrating sealers. Chemically, silane forms a covalent bond within the concrete material resulting in very high surface tension. The high surface tension creates a hydrophobic and oleophobic property that only wears away if the concrete itself wears away.

Siloxane is a functional group. Unlike silane, siloxanes are large and not highly reactive. They do not rely on the composition of the concrete to create a bond. Siloxanes react with the moisture in the atmosphere and bond together to form a hydrophobic, water repellent resin on the surface of the concrete. Siloxane is the largest molecular compound found in commonly available penetrating sealers and they are known to be superhydrophobic, less expensive, and responsible giving treated concrete a very cool water-beading effect.

In summary; Silanes protect by reacting with the silica inside the concrete, while siloxanes bond to each other. Sealers that contain both ingredients will give you protection inside and on the surface.

What are silicates?

Silicates are another small molecular compound ranging from premium lithium-based silicates to more economical sodium-based silicates. Chemically, silicates react to the calcium hydroxide to form calcium-silicate hydrate crystals which fill in the pores to densify and strengthen the concrete structure. Typically, they are used when burnishing to develop a solid, less porous, polished appearance. Silicates are cheap and will increase the strength of concrete by up to 50%. They are often advertised as a concrete sealer due to their ability to reduce the porosity of concrete, however, they do not modify the surface tension within or create a hydrophobic or oleophobic property on the surface. If applied incorrectly, silicates can over-react and cause difficult-to-remove white blushing. To remove this blushing, it can sometimes require grinding down the concrete with heavy equipment.

In summary; Silicates make for great concrete densifiers or hardeners prior to polishing and burnishing floors. Not the best option for sealing concrete, but when used in conjunction with a concrete sealer, can improve the performance of a sealer.

Fluorinated vs. non-fluorinated (aka contains fluorocarbons).

If the name sounds familiar, it's because fluorocarbon covers a broad family of compounds, and has been used in everything from Teflon, Scotchguard, and Freon. The carbon–fluorine bond is a covalent bond between carbon and fluorine atoms. It is one of the strongest single bonds in organic chemistry behind Si-F (silicone-fluorine). This strong bond also strengthens as more fluorine atoms are added to the same carbon atom in this compound chain. Fluorocarbons are colorless, odorless and have high density (up to twice that of water).

Due to their strong bonds and high density, they are often used to shield off liquids. Petroleum-based liquids like oil, fuel, gasoline and kerosene are far less dense than water and are known to easily penetrate surfaces. Fluorocarbons can prevent stains caused by oil-based liquids.

Similar to siloxanes, fluorocarbons bond to one another. They also have a high attraction to the silane compounds found in most penetrating concrete sealers. When applied to concrete, fluorocarbons and silanes react together to create a 3-way matrix that provides the ultimate in water, salt and oil protection. Abrasion tests and long-term studies have shown (by means of QUV weather tests and Gardner Linear Abrader – 2,500 cycles) that fluorocarbons alone and other polymers like acrylics and waxes eventually wear and offer no stain protection beyond 500 cycles. However, because fluorocarbons bond to the silanes below the surface of the concrete, the oil protection only wears if the concrete itself wears away.

In summary; Fluorocarbons create a nice dense, oil-proof shield. Fluorocarbons bond to concrete via silanes. Without silanes, their protection is short-lived.

Oil-repellent vs. oil-resistant. One in the same? Let’s see.

First, let’s look at the definition of repel and resist, as given by the Oxford English Dictionary.

Repel (v.): To drive back; ward off. Fight against. Refuse to accept.

Resist (v.): To reduce; withstand. Keep from giving in. To remain unaltered.

Oil-Resistant is the lowest level of protection. If a sealer is labeled oil-resistant, it means the sealer itself was not formulated to withstand exposure to oil. Oil may penetrate into the pores of the concrete, having no impact on the service-life of the sealer. However, the sealer itself was not designed to prevent the penetration of oil into the surface to which is was applied.

Oil-Repellent actually possesses the properties to repel oil, making the surface oleophobic. If a sealer is labeled oil-repellent, it means the sealer will create high enough surface tension to actually prevent oil from entering into the pores of the concrete. This makes removing oil stains simple and easy.

In summary; Oil-Resistant means that the sealer itself will not breakdown when exposed to oil. Oil-Repellent means the sealer will push oil away and prevent it from entering into the surface.

Active ingredients. All things are not equal.

Active ingredients are the ingredients within a formula that are biologically active. In contrast, inactive ingredients only act as a carrier. Most commonly available penetrating sealers contain active ingredients silane, siloxane, siliconate singularly or a combination there-of. These active ingredients react within the substrate and the moisture within the atmosphere to create long-lasting bonds. Formulations with higher levels of active ingredients will inherently perform better and last longer. Potency of the active ingredients can vary widely, so it’s important to search for this information when considering your purchase. Most manufacturers list their active ingredients on their website, or it can be found in TDS (Technical Data Sheets), SDS (Safety Data Sheets) or MSDS (Material Safety Data Sheets).

Most of the penetrating concrete sealers sold at the big box store will contain 5-20% active ingredients. The Department of Transportation requires at least 40% active ingredients to be approved for use on local, state, and national roadways or bridges. There are a select few manufacturers that offer 90-100% active ingredients in their formulas. Manufacturers that use high levels of active ingredients tend to include this information in their advertising, while those manufacturers using lower levels of active ingredients tend to minimize the use of active ingredients in advertising.

In summary; Higher actives mean better performance and longer service-life. Penetrating sealers rely on reactive ingredients to create protection. Potency is king.

ASTM Standards. What does that mean?

Originally known as the American Society for Testing and Materials, ASTM is an international standards organization that develops and publishes consensus technical standards for testing on a wide range of materials, products, systems, and services. These standards are optional for companies, but ASTM testing is used around the world to improve product quality, enhance health and safety, and build consumer confidence.

With over 12,000 testing protocols, for various purposes, a concrete sealer will be subjected to a series of tests to validate its efficacy in key areas of performance. For example, ASTM Test E-514 measures the amount of water penetration and leakage through masonry. In order to adhere to the standards of ASTM E-514, a sealer must perform well under the strict conditions outlined in the ASTM test protocol. If you find a penetrating sealer with ASTM Testing, there is a good chance the product performs. Manufacturers of products that have passed ASTM Testing like to tout these achievements because they are not easily achieved.

In summary; Look for concrete sealers that have been ASTM tested. This can prove a product works as intended or advertised.

Final Thoughts

Penetrating Sealers are different than most coatings because they protect from the inside and they are invisible. They keep surfaces looking natural so it can be difficult to know if the sealer is still doing its job. Once oil, water or road salt enter into the pores of the concrete, it sort-of too late. To ensure you protect the concrete, you’ll want to treat it with the best possible sealer. This will guarantee you protection without the worry. Now, you may be thinking to yourself, “I could buy a less expensive sealer and retreat every few years”. Yes, you could. However, you should know that retreating penetrating sealers can be tricky as they are designed to block liquids from entering into the pores of the concrete. Re-applying or refreshing a penetrating sealer may require grinding down the concrete surface with heavy equipment.

So, where does this leave us?

We’ve all heard the old saying, “You get what you pay for” and that could not be truer than with penetrating concrete sealers. If your goal is a budget-friendly garage floor sealer, you have plenty of options. Take a stroll down to the local hardware or big box store and you are sure to find a solution that addresses water and moisture intrusion for a few years. If you are looking for a penetrating concrete sealer that provides decades of prevention from cracking, pitting, spalling, efflorescence, and dusting plus worry-free stain protection from oils, fuels, and transmission fluids, then “pony-up” and buy a solution packed with higher active ingredients. Make sure it has silane, siloxane, and fluorocarbons. Fluorocarbons give you the oil protection. Siloxane gives you the water protection on top. Silane give you the inner protection and proper bonding. Make sure it penetrates deep. You only get one shot at long-term performance and protection and there is nothing worse than doing things twice.

If you are looking for oil protection on concrete, make sure it contains fluorocarbons and silanes like Siloxa-Tek 8510 and Siloxa-Tek 8505. Silane is the glue that binds all the important ingredients and both of these products will give you the longest-lasting possible protection from oil.

Why Ghostshield?

Siloxa-Tek 8510: Buy Now

  • Repels oil and grease making stains easy to clean
  • Stops deicing salt and chloride damage protecting concrete from spalling, pitting, cracking and freeze-thaw
  • Reduces water seepage by up to 95%
  • Resists mold & mildew reducing cleaning frequency
  • Leaves a natural finish, will not change the look of the substrate
  • Non-yellowing and UV stable. Will never peel, flake or delaminate
8510 Concrete Sealer Bottle

Siloxa-Tek 8510

Water, Salt & Oil Repel +

8505 Concrete Sealer Bottle

Siloxa-Tek 8505

Water, Salt & Oil Repel

Published Monday 15th of July 2024 // Updated Tuesday 26th of October 2021

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