The most popular brick water repellent sealer is a Silane-Siloxane water repellent sealer. Silane-Siloxane water repellents sealers perform better than silane sealers alone and siloxane sealers alone. To learn about the differences between silane sealers, siloxane sealers, and silane-siloxane sealers, view our Water Repellent Comparison article.

There are many benefits to sealing brick with a Silane-Siloxane water repellent sealer, including:

• Brick sealed with a water repellent sealer is more resistant to deterioration caused by water absorption including cracking, spalling, and pitting.
• Brick sealed with a water repellent sealer is more resistant to the growth of mold and mildew.
• Brick sealed with a water repellent sealer is more resistant to the formation of efflorescence.
• Brick sealed with a water repellent sealer is more resistant to staining caused by surface water absorption.

Silane-Siloxane water repellent sealers penetrate into the the surface of the brick where they chemically react to form a hydrophobic barrier within the pores. They won’t change the look or color of the brick, and they won’t leave behind a surface film or coating. Silane-Siloxane water repellent sealers are breathable, and brick will remain breathable once sealed.

Brick water repellent sealers can be used to seal a variety of horizontal and vertical brick surfaces including brick chimneys, brick walkways, brick pavers, brick patios, brick walls, brick homes, brick driveways, and other brick applications.

How To Seal Brick With a Water Repellent Sealer

Water repellent sealers are very easy to apply, especially on brick.

1. Make sure the brick is clean, and free of anything that could prevent proper penetration. Mold, mildew, and moss should be removed, and efflorescence should be cleaned. If a pressure washer was used, the brick should be allowed at least 24 hours to completely dry before sealing. For brick cleaning best practices, view the video below.
2. Water repellent sealers can be applied with a roller or sprayer. The best way to apply the sealer is with a high volume low pressure pump sprayer because you get better coverage and penetration. Rollers can be used, but less material is applied and the coverage isn’t consistent from brick to brick. When applying the sealer, be sure to apply the sealer to both the brick and the grout.
3. Brick is very porous and for that reason, two coats should be applied.
4. Once the water repellent has been applied to brick, let the brick dry for 24-36 hours. It can take up to 72 hours for water to start beading off the surface.

Best Brick Water Repellent Sealers

The market is flooded with water repellent sealers, but there are many differences between them. Here are some of the many ways in which Silane-Siloxane water repellents vary:

• Silane-Siloxane Ratio: This information will never be published because it is considered proprietary. Hybrid sealers don’t necessarily mean that there is an equal amount of both sealers. The price can be an indicator, but not always. Unfortunately, the only way to tell how good a sealer is and how well it performs, is to try it.
• Certifications: Not all manufactures post information about this because not all products quality. Some products have been tested and approved for industrial uses, while others have either not been tested, or failed. Take for example the Armor SX5000 sealer. The Armor SX5000 has been tested and approved by the Department of Transportation in several states to be used as a water repellent sealer for roadways and bridge decks. It has been used in industrial applications and passed as a preferred product.
• Water vs Solvent Based: Water and solvent based water repellents will offer the same benefits an done does not perform better than the other when applied on brick. One thing to think about is windows and siding.  If the brick is surrounded by windows and siding you may want to apply the water based because it can easily be cleaned up with water.

Frequently Asked Questions About Brick Water Repellent Sealers

1. How long do water repellent sealers last on brick? Water repellent sealers last for up to 7-10 years. The “bead” will go away within the first year but the sealer will continue to work within the pores for up to 7-10 years.
2. Can I use a siliconate water repellent sealer instead? The issue with siliconate water repellents is that when applied to dark or colored surfaces, or very porous surfaces, they can leave behind a white crystal residue. Brick is dark, colored, and porous so the chances are very high of the brick turning white if a siliconate water repellent is used.
3. What types of bricks can be sealed with a water repellent sealer? All bricks can be sealed with a water repellent sealer. Clay bricks, concrete bricks, and engineered bricks.
4. Can I seal the grout too? Yes, the grout can be sealed with a water repellent sealer too.
5. What if my brick was previously sealed? If your brick was previously sealed with a siliconate densifier, there are no issues. If your brick was previously sealed with a water repellent sealer and you are trying to reseal, you want to make sure that the old sealer is gone. If you splash a cup of water against the brick and the brick instantly absorbs the water and gets absorbed in, that usually means the old sealer is gone. If there is currently an acrylic sealer or paint on the brick, that would need to be removed before applying a penetrating sealer.
6. How deep do water repellent sealers penetrate? Water repellent sealers can penetrate anywhere from 1/4″-6″ depending on the porosity of the brick and how much material is applied. There is no way to measure or predict penetration. Brick is very porous so typically penetration is good. It is important to keep in mind that the penetration depth is not nearly as important as the quality of the water repellent barrier formed.