• • Acrylic resin-based sealers: Sealers that lay down a film of acrylic resin provide excellent performance for their cost. They may be blended with epoxy, polyurethane, or silicone to enhance the durability of the product, so read labels carefully. There are different types of acrylics, too, and some are better than others. Styrene acrylic is a lower-performance product that may turn yellow under direct sunlight. A better choice is a type known as virgin or pure acrylic resin, which will last longer and will not turn yellow.
  • Epoxy or polyurethane sealers: These cost considerably more than acrylics, but the high costs do not really mean they are superior. They lay a thicker layer, so can be slippery, especially when coated onto a patio or walkway. These products also prevent the concrete from “breathing” moisture out of the concrete, which is a problem. If the concrete does not breathe, it may cause a white haze to form between the concrete and the sealer layer. 
  • Penetrating sealers: These products are made of specialty resins (silicones, siloxanes, and silanes) that penetrate into the concrete and form a chemical barrier to water, oil, and other common contaminants. Such products will be clearly labeled as “penetrating” sealers, and are a good choice where you want to protect surfaces against stains, such as in a garage or on a driveway. 

The very best products will be available at professional concrete supply retailers. The inexpensive products offered at hardware stores and home centers tend to be intermediate-level sealers that provide adequate performance but will likely have a shorter useful lifespan than more expensive professional-grade sealers.