Penetrating concrete sealers, such as silanes, siloxanes, and silicates, penetrate into the concrete to form a chemical barrier that shields against moisture penetration and deicing chemicals. Usually they provide invisible protection without changing the surface appearance, and most products are breathable, allowing moisture vapor to escape. They are most commonly used outdoors, since they provide excellent protection against harsh exposure conditions. Prior to applying sealer the concrete must be prepared by shotblasting, this will ensure the best results. Applying a penetrating concrete sealer to your parking garage will prevent gas, oil and salt particles from penetrating into the concrete pores. Harsh chemicals can begin delaminating your concrete causing expensive repairs in the future.