Concrete stains offer homeowners a simple do-it-yourself project that will improve the look of their home, and make plain concrete flooring attractive and appealing. Unlike many home improvement projects that require expensive supplies, concrete stain can be made cheaply and safely in your own home.
What is Concrete Stain?
Concrete stain is a special chemical wash that changes the color of a concrete surface. Unlike paint, which applies a layer of colored material over a surface, stains permanently change the color of the concrete itself. It does this by reacting with the lime that is found in all concrete. The chemicals in the stain react with the concrete, changing the color. The resulting color is dependent upon the type and amount of chemicals used in the stain. Because stain works differently from paint, it won't coat the surface. Like wood stain, concrete stain doesn't produce a uniform color, either. Instead, it will bring out natural variations in the concrete, producing a variegated, marbleized look. Be aware that any cracks or flaws in the concrete will also be highlighted. Two popular stain recipes may be used to produce two very different looks. The first uses iron sulfate, which produces a tan, coppery color. The second, which uses copper sulfate, produces blueish and greenish tones.
To produce a stain with rich brown tones, iron sulfate is the easiest to mix and use. Iron sulfate can be found commercially as Copperas, a product made by Hi-Yield gardening supply. It is often sold through gardening and home improvement retailers in 5-lb. bags. In a large, non-metallic container, mix 6 cups of iron sulfate powder for every gallon of warm water. Mix with a non-metallic stick or implement until the powder has dissolved. The end result should be a tan, watery liquid. Test the stain on a small patch of concrete. When applied, it will merely look wet, but as it dries and reacts it will take on more color. If the dried color is not to your liking, it can be lightened by adding more water, or darkened by adding coffee.
For a stain that produces blue-green tones, copper sulfate is a simple alternative. Copper sulfate is sold as root killer for use in septic tanks and sewers, and is available through most hardware stores under various brand names. In a large, non-metallic container, mix 4 cups copper sulfate crystals to every gallon of warm water. Mix well until the crystals dissolve, resulting in a bright blue mixture. Test the stain, and let dry. The result should leave your concrete lightly tinted blue. Once the stain has set, wet the surface again to get an idea of how the color will look under a sealer. If the color is not to your liking, it is simple to change. For a more visible blue, add more copper sulfate to the mixture. To make the results a lighter tint, add more water. To create a greener color, add regular table salt.
Before applying stain to concrete, it should be swept and scrubbed, with any stains or spots removed. Any stray glue, caulk or oil should be removed as well. If the concrete is already sealed, the sealer must be removed before any stain is applied. While many commercially available stains are applied to a wet surface, these stains are not. Wait for recently scrubbed concrete to dry before applying any stain. Stain may be applied in a number of ways. Paint brushes, paint rollers and sponge mops may all be used. Some people choose to use a sprayer. If using a sprayer, be sure to strain the stain mixture through a filter or cloth first to remove any undissolved material. Once the stain has set, use a sealer to protect the concrete surface. This will not only protect the porous surface of the concrete, it will also prevent spills and sunlight from changing the look of the stain.