There is some debate regarding if and when concrete surfaces require sealing. Skeptics suggest that sealing is unnecessary and that concrete performs adequately on its own. However, even most of them agree that periodic sealing can prolong the life of concrete installations including pool decks, sidewalks, driveways, patios, lanais, and parking lots. This is especially relevant in the case of stained or etched concrete or in areas where the concrete will be subjected to adverse weather conditions or road salt.
When considering concrete sealers it helps to know the options as well as the difference between an acrylic resin-based sealer, a penetrating sealer, and an epoxy or polyurethane sealer.
Acrylic resin-based sealers guard concrete with a film of acrylic resin and provide good cost-effective protection. These sealers may be blended with other products such as epoxy, silicone or polyurethane. One product, styrene acrylic may turn yellow in direct sunlight, but virgin or pure acrylic resin will not, and it will last longer.
Made from specialty resins such as silicones, siloxanes, and silanes, penetrating sealers protect concrete by—as their name suggests—penetrating into concrete and forming a chemical barrier against common contaminants. These can help protect against surface stains and are a popular choice for garage floors or driveways.
Epoxy or polyurethane sealers are costly and thick which can make them not the best choice for patios or walkways as they can make the surface slippery. Additionally, these products do not allow concrete to “breathe” moisture out which might result in a haze forming between the concrete and the sealer.
Another consideration is the gloss level. Like paints, concrete sealers are available in no-gloss, matte, satin, semi-gloss, gloss and high-gloss options. Manufacturers categorize these on a scale of 1-100 with 100 being the highest level of gloss.
Solvent-based sealers have a gloss level of 80-100 resulting in a gloss to high-gloss surface.
Water-based sealers have a gloss level of 50-80 resulting in a matte or semi-gloss surface
Penetrating sealers have a gloss level of 0 resulting in a no-gloss surface.
Solvent-based sealers tend to darken the surface of the concrete more than water-based sealers.
Regular maintenance and periodic reapplication of sealer will keep concrete surfaces beautiful for years to come; although, how often this is required varies based on personal preference, climate, and wear and tear.