The Concrete Network

Applying a transparent concrete sealer to an exposed aggregate surface can improve both its performance and appearance. These sealers-typically film-forming acrylic resins-can help protect against spalling, dusting, efflorescence, freeze-thaw damage, stains, deicing salts, and abrasion. A sealer will also enhance the color of the aggregate, accentuating its depth and richness.

When selecting an exposed aggregate sealer, look for a product that:

  • Is non-yellowing and UV resistant

  • Will provide a high-gloss wet look that deepens and enriches the color of the aggregate

  • Repels oil, grease, water, and stains

  • Is recoatable

When applying the sealer to fresh concrete, make sure all cement paste residue from the exposure process has been thoroughly removed to avoid sealing the milky-looking white paste on the surface. On existing exposed-aggregate concrete, thoroughly clean the surface from oil, grease, dirt, and stains before applying a sealer. (See Cleaning Concrete.) Use a short-nap roller for the best application results.

Expo-Gloss from W.R. Meadows and Wet Look Lacquer from White Mountain are examples of sealers formulated specifically for use on exposed aggregate concrete. These products should be applied to clean surfaces that are free of contaminants. A brush, short-nap roller, or airless sprayer can be used.

Whichever brand of concrete sealer you use, be sure to follow the specific instructions for the product, both for surface preparation and application, and make sure the sealer is recommended for use on exposed-aggregate concrete. This link provides a list of concrete sealer manufacturers.

Exposed Aggregate Maintenance