Silane-siloxane sealers chemically react to form a water repelling hydrophobic barrier within the pores. They do not leave behind a visible surface film or coating. They reduce the absorption of surface water, therefore reducing damage and deterioration caused by water absorption such as freeze-thaw damage, cracking, spalling, and the growth of mold and mildew. Silane-siloxane sealers will last for up to 7-10 years before the need to reseal.
Acrylic sealers enhance concrete with a wet look, low gloss, or high gloss finish. They leave behind a visible surface film that is designed to protect the concrete against damage and deterioration caused by surface abrasion, water absorption, and exposure to the elements. Acrylic sealers will need to be reapplied every 1-3 years.
Both Silane-Siloxane sealers and acrylic sealers are great concrete sealers. The type of sealer that is best for your application depends on what you want the concrete to look like once sealed, and what you need the concrete sealer to offer in terms of performance.