How to paint concrete floors

Before you begin, it’s important to determine whether the concrete has been previously sealed or coated. To test this, pour some water onto different areas of the floor and let it sit for about a minute. If the water soaks in, the surface is uncoated. If the water beads on top, this indicates that a previous coating has been applied. Identifying whether the concrete has been sealed will help you decide on the best preparation method for concrete painting. 

If a coating is present, you may need to remove it before painting. The best approach depends on the condition of the existing coating and the type of paint system you are using. In some cases, the previous concrete sealer or paint can be removed by grinding the surface back. However, in many instances, a good acid wash and the right primer will be enough to prepare the floor without the need for grinding. Always check the paint manufacturer’s instructions to determine the best preparation method for your specific product. 

A clean surface is essential for good paint adhesion. Start by pressure washing the entire area to remove any dirt, dust, or loose material. Mix the concrete cleaner in a bucket according to the manufacturer’s instructions, then use a stiff bristle broom to scrub the floor thoroughly. Let the concrete cleaner sit for about 15 minutes, ensuring the surface does not dry out. 

If your concrete is bare or uncoated, you will need to use an etcher before priming. Follow the product instructions carefully to prepare the surface properly. For heavily stained areas, multiple cleans may be required. Before rinsing off the cleaner, target any stubborn stains with additional scrubbing. Use a high-pressure washer to rinse the entire surface, then allow it to dry completely before moving on to the next step. 

Priming is essential for ensuring strong adhesion and a smooth, even finish. In this case, the driveway has a previous coating, so we are spot-priming areas where the coating has lifted and applying a pre-coated primer to the rest of the surface. If you are spot-priming, apply two coats for extra durability. 

Start by using a paintbrush to cut in around walls and edges where a roller can't reach. Then, using a roller with an extension pole, apply the concrete primer evenly across the entire surface. Work in small sections to ensure an even application. Let the primer dry for the recommended time stated on the packaging, which is typically a couple of hours, but always double-check before proceeding. 

Once the primer has dried completely, it’s time to paint. Choose a concrete paint primer specifically designed for this type of surface. Start in a corner of the area and work your way out, using a roller for larger sections and a paintbrush for edges and tight spots. Just like with the primer, apply the paint in thin, even coats, allowing each coat to dry fully before applying the next. You may need two to three coats to achieve a smooth and even finish. 

After applying the final coat, allow the paint to cure fully before using the area. Drying times will vary depending on the product and weather conditions, so check the manufacturer’s recommendations. Avoid heavy foot traffic or placing any furniture on the surface until the paint has completely hardened. If painting a driveway or garage floor, wait the recommended time before driving on it to prevent damage. 

With the right preparation and application, your painted concrete floor will have a fresh, durable finish that lasts for years.