What kind of concrete sealer do you need? That is pretty much the simple question most homeowners want answered. In an effort to simplify concrete sealers, there are only two groups of concrete sealers to be concerned about; penetrating sealers and topical sealers. These are essentially the same for other types of materials such as stone, brick, and tile sealer. Penetrating sealers are sealers that penetrate the slab from ¼ inch to 4 inches. These sealers are superior to coating sealers in that they penetrate deep into the pores of the concrete. Coating Sealers are less expensive than penetrating sealers. These types of sealers are still very good at helping the concrete to cure evenly. The downside is that, although cheaper, they will require more frequent applications
Penetrating Sealers (chemically reactive)
Silane; must be applied heavily which may darken concrete, life span 5-8years with good saturation, less stain resistant, cost is higher due to heavy application rates
Silicate; applied after 7-14 days; permanently binds with concrete to seal slab and reduces the porosity of the concrete; heavy application required to get protection on the surface, difficult to penetrate smooth floors, difficult to get heavy coat on broom finished slabs, agitate with a brush
Siliconate; can be used as a cure and seal when applied day of the pour, permanently binds with concrete to seal slab by reducing porosity, best water repellent with long life span, large molecular compound for porous finishes. Overall good choice for driveways.
Coating Sealers (film-forming; similar to paint)
Siloxane; very similar to silicone
Silicone; low UV resistant; low lifespan; low abrasion resistant, low chemical reaction making it a film- forming type sealer
Acrylic; life span of 3-6 years, water based, cheaper alternative, two coats recommended, can yellow with age, basically a clear paint
Polyester; twice as thick as acrylics, most polyurethanes are moisture intolerant; which means the surface must be dry when the sealer is applied or else a chemical reaction will occur that results in foaming.
To summarize, the best topical concrete driveway sealer is a Polyester based product with Acrylic based products being next in line. The best penetrating sealer is a Silconate based product. Coating or topical sealers are cheaper but won’t last nearly as long, requiring more frequent applications. Penetrating sealers are more expensive initially but will require fewer applications and protect your concrete driveway for years to come, never requiring a second application.