What is a penetrating sealer? A penetrating sealer is a sealer that penetrates deep into the surface of the concrete or masonry where it chemically reacts below the surface from within the pores. Penetrating sealers do not leave behind a visible surface film, and most of them will not change the look or color of the surface.

Types of Penetrating Sealers: Sodium Silicate and Lithium Silicate

Under the category of silicate sealers, there are sodium silicate sealers and lithium silicate sealers. Potassium silicate is on the market but is not high enough quality for masonry work. Sodium and lithium silicate sealers penetrate into the surface where they chemically react with the free lime and calcium within the pores. The reaction forms a permanent calcium silicate hydrate structure that resembles a crystalline structure. The goal with silicate sealers is to increase the strength and density of the concrete surface.

Uses: Silicate sealers are used for a variety of purposes, including part of the concrete polishing process. The increase in strength and density gained from a silicate sealer make them popular for use on:

  • Basement floors and walls for reducing the movement of water through the pores
  • Concrete driveways to help reduce freeze-thaw and salt damage
  • Warehouse floors to help reduce deterioration caused by surface abrasion

Common Questions about Silicate Sealers:

  1. Is it true that a silicate sealer can penetrate up to 6 inches? It isn’t the silicate that determines the penetration, it is the porosity of the surface the silicate is being applied to. Dense surfaces, like polished concrete, don’t absorb much material, so a sealer will only penetrate about a half inch to two inches. Porous surfaces, like broom finished concrete, are very porous and will absorb a lot of material. Silicates can penetrate anywhere from 2-6” on a porous surface.
  2. How long does a silicate sealer last? The CSH formed from the chemical reaction caused by the silicate and permanent. The CSH can only be removed when the concrete itself is removed.
  3. Do silicates bead water? No, silicates do not bead water. If you want water repellency characteristics you need to apply a water repellent sealer 5 to 7 days after the application of the silicate.
  4. Do silicates change the look or color of the concrete? No. In some cases, when a silicate is over applied, white crystals can form on the surface. This is not common when properly applied.
  5. Can you apply silicates to bricks or pavers? Silicates can be applied to bricks or pavers, but over-application becomes an issue. If applying to anything other than concrete it is important to you, apply it to a test area first to verify compatibility and coverage.
  6. Are all silicate sealers the same? The chemical reaction formed from one silicate to the next is identical, but the silicate sealers themselves are not the same. Many manufacturers sell silicates which are pre-diluted, while a few manufacturers sell them in concentrate and allow the buyer to dilute them with water before applying.
  7. Can silicates stop radon? No. While some manufacturers use this as a benefit to sell product, it is false. Radon is a gas and silicates are breathable. Gases that came into the concrete before being sealed will still come through after being sealed. The most effective way to mitigate radon is with a radon mitigation system.
  8. Can I put this down before installing hardwood, carpet, tile, or drywall? You can but in many cases, a silicate sealer is not enough. Silicate sealers fill up some of the pores, but they do not fill up the entire pore. They are designed to remain breathable. While water and moisture can be reduced, it won’t be stopped. An epoxy designed for moisture mitigation is more effective.

Types of Penetrating Sealers: Siliconate Sealers

Siliconate sealers are water repellent sealers that chemically react below the surface to form a hydrophobic barrier within the pores. This is a very effective solution for reducing damage caused by the absorption of water, snow and ice, and road salts. When applied to overly porous substrates or colored substrates, they can leave behind a white residue if overapplied. Siliconate water repellents are great for use on white or light gray concrete surfaces.

Uses:Siliconate sealers are used as water repellent sealers because they aggressively bead water off the surface. They are commonly used to

  • Seal concrete driveways, warehouse and shop floors, and garage floors
  • Reduce deterioration caused by water absorption such as cracking, spalling, pitting, freeze-thaw damage, and salt damage
  • Help to reduce the formation of mold, mildew, and efflorescence

Common Questions about Siliconate Sealers:

  1. Are siliconate sealers the same thing as a silicate sealer? No! Silicate sealers are used to harden and densify concrete and do not repel surface water; siliconate sealers repel surface water and do not harden and densify concrete.
  2. Can I apply a siliconate sealer over a silicate sealer? Yes, you can, 5 to 7 days later.
  3. Is a siliconate water repellent better than a silane siloxane water repellent? One is not better or worse, but one is more appropriate than the other in certain applications. For example, siliconate sealers work best when applied to very light concrete surfaces. Applying them to dark or very porous surfaces, like brick or pavers, can result in white residue formation on the surface. Silane-Siloxane sealers are popular in industrial applications, such as sealing roadways and bridge decks, and they also work great on sealing porous surfaces like pavers and bricks.
  4. Can I apply an acrylic sealer over a siliconate water repellent? If you plan on applying an acrylic sealer, you are better off going with a solvent-based silane-siloxane sealer which is compatible with solvent-based acrylics.
  5. How long do siliconate sealers work?Siliconate sealers offer up to 7-10 years of performance.

Types of Penetrating Sealers: Silane-Siloxane

Silane siloxane sealers are water repellent sealers that chemically react below the surface to form a hydrophobic barrier within the pores. They are very common for use in industrial applications such as sealing roadways and bridge decks. Also, homeowners choose use them to seal their driveways, walkways, patios, and garage floors. They help to reduce deterioration caused by water absorption and help reduce the formation of mold, mildew, and efflorescence. It is important to understand that a silane/siloxane hybrid product works very different from a silane sealer or a siloxane sealer. Silane and siloxane sealers have several weaknesses when used independently, but when used as a hybrid system contain the straights of each sealer without the weaknesses.

Uses: Silane-siloxane sealers are used as water repellent sealers for a variety of industrial, commercial, and residential applications. They can be used to:

  • Seal everything from concrete to pavers, bricks and stone
  • Seal warehouse and shop floors, garage floors, driveways, walkways, patios, pool decks, sidewalks, buildings, roofs, and more

Common Questions about Silane-Siloxane Sealers:

  1. Can I use this on my driveway even though it is used primarily on industrial applications? Yes, silane-siloxanes are very popular to use in both residential and commercial applications.
  2. Will silane-siloxane sealers bead water forever? No. The bead on a silane-siloxane sealer goes away after 2-12 months, but the product continues to work within the pores for up to 10 years.
  3. Can I apply an acrylic sealer over it? Yes, you can apply a solvent-based acrylic sealer over a surface previously sealed with a solvent-based silane siloxane sealer.
  4. How are silane siloxanes applied? Silane siloxane sealers are applied with a roller or sprayer. While one heavy coat may be enough on some surfaces, two coats are always suggested.
  5. Are all silane-siloxane sealers the same? No, in fact there is a dramatic difference in formula from one manufacturer to the next. May products found in big box stores contain 2 to 8% solids (or active materials), while other manufacturers online offer 20 to 40% solids (active materials). The more active materials, the better – to a point. On a residential application, the solids content should not exceed 40% to avoid darkening of the concrete surface.

Other Options

Acrylic Sealers - While many manufacturers refer to acrylic sealers as sealers, they are not penetrating sealers. They penetrate in order to form a bond, but they function more like a coating. They enhance the surface and leave behind a visible, protective surface film. If you are looking for a wet look, low gloss, high gloss, or colored finish, you want an acrylic sealer.

Purchasing a Penetrating Sealer

If you still have questions about making a purchase or you want to purchase a product made to last, Foundation Armor is here to help. Our qualified technicians are available on live chat or by phone at (866) 306-0246 for a consultation. We help you find the right product to purchase.