The two types of concrete stain that can be applied to new or existing concrete are acid stains and water- based acrylic stains. Both types of concrete stain can be used indoors and outdoors and both are good DIY projects with varying degrees of difficulty.
Types of Concrete Stains
When you stain concrete, you are enriching the appearance of the surface. By using different colors and changing the application technique you use, you can create a rich decorative effect that is uniquely your own. It is also a way to breathe new life and vitality into existing concrete that has dulled over the years.
Acid Based Concrete Stain
Acid based stains are usually purchased in a ready-to-use form. You can dilute them with muriatic acid to achieve lighter shades of your chosen stain color. Acid based stains are translucent and are well-known for the depth of color and stunning visual effects they create. These stains are a combination of water, hydrochloric acid and acid soluble metallic salts.
When applied, the acid first etches the surface of the concrete. Now the stain can penetrate into the concrete where it reacts chemically with the calcium hydroxide in the concrete. This chemical reaction produces color that is permanent and won’t fade, peel, or chip away over time.
The effects that acid stains produce are distinctive and vary across the surface. This imparts a richness and character to the concrete. Acid-based stain colors are generally available in earth tones and, to a lesser extent, blue-greens. A wider color palette is available by using water-based stains.
Water Based Concrete Stain
Water-based stains come in a pigment and base resin that you mix together. There are many more color choices with water-based stains and the stains themselves can be mixed together to achieve just the right shade. Diluting the stains with water also produces varying degrees of opacity in the stain. Unlike acid-based stains, there is no chemical reaction with these stains so color is much more consistent throughout the concrete surface.
Another benefit of using water-based stains are that they are low in VOCs (volatile organic compounds) with less odor and are an eco-friendly choice for staining concrete.
Both types of stains are excellent for interior and exterior uses because, since they actually penetrate concrete, they are UV stable and wear well. However, water-based stains are usually an easier product to work with. There are few safety precautions with water based stains, tools used needn’t be acid-resistant, and clean-up is easier with just soap and water.
Many DIYers are learning concrete staining techniques to add value and distinction to their homes. Other considerations when using concrete stain can be found on this site in these articles: