How to Color Exterior Concrete

Clean the surface of the concrete to remove dirt, debris, stains or any white concrete efflorescence. Wash the surface with a pressure washer to remove most grime deposits. Apply a concrete degreaser to any oil deposits and allow it to sit for about 15 minutes before scrubbing the oil away. Spray a mix consisting of equal parts white wine vinegar and warm water over the white efflorescence stains and scrub the area with a wire scrub brush until you've removed all traces. Use the pressure washer again to remove all cleaning products. Allow the concrete to dry for 24 hours prior to painting.

Mask off adjacent surfaces. Place a strip of masking tape along the adjacent edges to prevent paint splatters or drips. When painting a wall or other vertical surfaces, place a drop cloth along the base of the surface to catch any dripping paint.

Apply a layer of primer to the concrete using a thick-nap paint roller with an extension attachment. Use an acrylic block fill as the primer for your surface. Use a paintbrush to cover the edges of the surface with the paint. Paint along the edge covering a strip of about three inches towards the center of the concrete surface. Switch to the roller to complete the coverage by applying the rest of the primer in rows overlapping the edge of the paint and then overlapping each row by half the roller width until reaching the other edge. Apply the coating in multiple light layers to ensure even coverage. Wait for the primer to dry before the application of the top coat of paint.

Paint the surface of the concrete your chosen color by applying two coatings of elastomeric paint with a paint roller. Use the same process for application as that used for the primer paint, waiting about two hours between the coatings for the paint to begin to dry. Wait for the final coating of paint to dry completely before using the concrete surface.