A concrete sealer is used to prevent moisture from getting into the concrete matrix. As a result, this limits surface deterioration that is caused by cycles of thawing and freezing. A high-quality sealer also protects the concrete from exposure to grease, chemical, and oil stains. Sealers for exterior concrete are available in tow types; penetrants and film-formers with penetrating sealers, offering the utmost protection from moisture absorption. Before applying the concrete sealer, it is recommended to allow the concrete to air dry fast for 30 days. When it comes to application rates and how often you should apply it, be sure to consult with the manufacturer’s directions.