Polyurethanes concrete sealers are nearly twice as thick as an acrylic sealer and form a high-build protective film on the concrete surface. It provides superior resistance to abrasion and chemicals. Another interesting fact is that polyurethane concrete sealers are available in water and solvent based versions in a wide range of sheen levels.
You can use polyurethane concrete sealers on either an interior or exterior concrete in order to create a transparent and non-yellowing durable finish.
There are three typical applications for polyurethane sealers. One reason for an application of a polyurethane sealer is to provide better resistance to scuffs and staining. Polyurethane sealers enhance the beauty of colored, stamped, or exposed aggregate concrete. In addition, they work well for concrete countertops.
Polyurethanes, for the most part, are moisture intolerant until they cure. This means that they should not be applied to places where water is present. If this does happen, a chemical reaction will occur. This chemical reaction will result in foaming and bubbling. Another thing to keep in mind about polyurethanes is that they do not allow for moisture vapor to move out of the concrete, which can pose problems on certain exterior concrete surfaces. A driveway is one good example.
When applying polyurethane sealers, remember that they require more care when applying in contrast to other single-component sealers, such as acrylics. When it comes to spraying, make sure to avoid any garden-type pump-up sprayers since they don’t reach the level of pressure necessary for a thin or even spray pattern. A low-volume and high-pressure airless sprayer works well for these occasions. You could also opt to use a micro-fiber mop which will give you full and even coverage.