Concrete sealers can usually be classified as either penetrating or topical. Topical sealers are usually of the acrylic, epoxy or urethane variety, as its name suggests sitting on top of the concrete. Penetrating sealers, as its name suggests, penetrate deep into the concrete chemically reacting or impregnating to seal from the inside out.
Penetrating sealers most commonly come in the form of silicates, siliconates, silanes, siloxanes or blends:
Sodium silicates have been around for almost a century and are an excellent choice for densifying concrete, however keep in mind that sodium silicates are not waterproofers. They may densify and strenghten but they will not be effective against active water or moisture intrusion. Product recommendation: Sila-Tek 3500
Lithium silicates are a newer densifying technology with added benefits of combating ASR, and deeper penetration than a sodium silicate. Product recommendation: Lithi-Tek 4500
Silicate/Siliconates: are a blend of a silicate densifier and a siliconate waterproofer. The combination of the two products strengthens and hardenes concrete filling in all the tiny pores and capillary voids, while the siliconate component renders a hydrophobic surface environment resisting water, mold, mildew and efflorescence. Product recommendation: Lithi-Tek 9500
- Silane/Siloxanes: are a blend of silanes and siloxanes which are excellent choices when used as water and salt repellents. Some variations also include a fluro polymer which makes them resistant to oils and staining from grease and leaves. Product recommendations: Siloxa-Tek 8500, Siloxa-Tek 8505, Siloxa-Tek 8510