How to Use a Stamped Concrete Release Color Without Much Contrast

Rinse the old concrete well with the garden hose. If the concrete has grease stains, mix several drops of dish detergent in a bucket of hot water and scrub the surface. Rinse well with clean water.

Etch the concrete to roughen the surface. Mix 5 parts water to 1 part muriatic acid in a plastic garden sprayer. Soak the surface of the concrete for five minutes. Rinse the concrete thoroughly with clean water.

Neutralize the acid with a mixture of 5 parts water and 1 part ammonia. Use the garden sprayer to soak the concrete. Rinse with clean water.

Create forms to hold the concrete overlay on top of the existing concrete. Use furring strips held in place with stakes. Extend the furring strips 1 inch over the top of the existing concrete.

Stir together 1 part Portland cement and 2 1/2 parts sand. Add water until the mixture has an oatmeal consistency. Add enough coloring agent to the mixture to achieve the desired color. Notice how much coloring agent and water you used in case you need to mix more concrete overlay to finish the project.

Mix a separate batch of 1 part Portland cement and water to make a paint-like substance. Dampen the old concrete but don’t allow water to puddle on it. Paint the watery concrete mixture on the dampened concrete, using an old paintbrush.

Pour the concrete overlay over the concrete paint to the tops of the furring strip forms. Work it into all the corners and along the edges. Smooth in place with a trowel. Turn the trowel sideways and make a trench between the edge of the overlay and the furring strips. This makes it easier to remove the furring strips later and makes a clean edge for the overlay.

Use your hands to sprinkle low-contrast colored release agent over the damp concrete when the concrete no longer has a sheen to it. Sprinkle release agent onto the concrete stamp as well.

Set the concrete stamp into the overlay just deep enough to leave the pattern in the concrete. Pull it straight up. Align the stamp with the pattern from the first impression and press the stamp into the concrete to make the next impression. Repeat this process until you finish stamping the entire surface. Add more release agent to the stamp, as necessary.

Rinse the release agent from the overlay after the concrete cures for two days. If you want even less color contrast, use a pressure washer to remove the release agent. Remove the furring strip forms.