Not all home improvement experts agree on what is better, concrete paint or concrete stain, because it depends on your desired results. Concrete stain embeds the surface to color it translucently, while opaque concrete paint covers the top of the concrete but is subject to chipping and peeling when improperly applied. Concrete stains go on quicker, dry faster and take less work than concrete paint, but they offer no significant protection. A paint designed for masonry -- an elastomeric paint -- covers and protects the concrete's surface and keeps it from drawing in moisture, and it won't chip or peel if the concrete surface is properly prepared. In the end, the option that works best depends on where you want to use the product.
With two basic types of concrete stains, the easiest option is the water-based stain that goes on quickly after you clean the concrete. It usually requires a sealant after application to prevent fading. Acid-based stains react to the concrete's ingredients, offer fewer color options than water-based stains and are a bit more complicated to use. Water-based stains can require more than one application of the stain if you want to deepen the color. Concrete stains give you a decor option for coloring concrete floors, but they don't actually protect the concrete. Acid-based stains can be dangerous when applying, and can cause severe skin, eye and lung irritation. The use of face masks, heavy gloves and protective gear are needed.
Concrete paints completely cover and protect the concrete surface, but require a lot of prep work. Before you can apply a concrete paint, clean it with degreasers to get rid of any oil or grease stains, followed by muriatic acid to remove any curing chemicals on the concrete's surface. (Muriatic acid is extremely dangerous if inhaled, and prolonged exposure can cause circulatory failure. Use caution and read all instructions before working with muriatic acid.) Seal the concrete with a primer-sealer product to prevent it from moisture retention before applying a concrete paint. Concrete paint works for both indoor and outdoor application, as does a concrete stain.
Manufacturers have created two-part epoxy concrete floor covering products that don't require you to seal or prime the concrete ahead of time -- as long as it is clean. Many people choose this option for garage floors. The epoxy coating leaves a shiny surface sometimes impregnated with bits of colors or aggregates for a decorative touch. These sealed surfaces can last for a long time when cared for properly. Like the other options, epoxy is hazardous when applying, and the area should be well-ventilated when working.
Pros and Cons
Concrete stains work well on interior or exterior surfaces to add color to the concrete; when sealed and polished they create a high sheen floor, an easier solution to use for interior decorative floors or outdoor patios. Because stains are translucent, they won't hide any of the concrete's flaws. Concrete paints also provide a decorative touch, but are better suited to applications where the concrete also needs sealing and protection -- inside a garage or basement, for example, or where you want to hide damaged or stained surfaces. Epoxy paint is used similar to resins, in that you add a catalyst to activate it. These products work best in areas with heavy use, such as garage or workshop floors. The drawback to these paints is that you must apply all the paint once you add the catalyst, because once it hardens, it's unusable. All products have safety concerns that should be considered, since some of the chemicals and acids used can be extremely dangerous to apply.
You can also add stains to concrete when adding new concrete for a patio. This type of stain impregnates the concrete through and through, and becomes part of it. Masons often include a pigment in concrete when they stamp it to make it look like brick, paving stones or natural stone driveways, walkways and sidewalks.