Fix-it Chick: Several options to get color match with new, old concrete
Whether it’s a small patched area or a whole new addition, matching old concrete to newly poured concrete is a big challenge. Though it is nearly impossible to achieve a perfect match, there are several options that may help reduce the glaring differences between new and old concrete.
Step 1: Clean the old concrete with a strong concrete cleaner and a stiff bristle brush. Allow the cleaner to soak into the old concrete before using a pressure washer to finish the job.
Step 2: Before pouring the new concrete, add a bit of black or brown concrete stain to the mix to imitate the old concrete patina. Try several test batches before deciding on the best formulation for the new concrete.
Step 3: To give an aged appearance to concrete that has been poured and cured, rub watered down black or brown stain into the surface of the new concrete. Try small test spots first before attempting to alter the color of the entire surface.
Step 4: Covering newly poured and cured concrete with a layer of moist topsoil for several days can sometimes help to achieve a darkened, aged look. Mist the soil for several days and then remove all but a thin layer of the soil. Walk on the remaining soil for a day or two, then use a garden hose to rinse the soil away.
Step 5: If all attempts to color match the new and old concrete fail, consider staining the entire surface with a colored acid-based or water-based concrete stain. Acid base stains are more durable and will last much longer, but water-based stains are easier to use and will give the surface an enduring finish that can last for several years.
Step 6: Concrete paint or fortified concrete solid stain products are another option for matching old and new concrete surfaces. Paint or solid stains are available in a wide variety of colors and can be brushed over the entire surface for a completely homogeneous appearance.
Step 7: To achieve a completely uniform look between new and old concrete, use a polymer-modified concrete resurfacing product. Mix the product according to the manufacturer’s instructions and squeegee a thin layer evenly over all of the existing concrete. Use a broom or brush to lightly texture the surface and allow the product to dry to a new, durable and perfectly matched finish.
— Have a home improvement question for Fix-It Chick? Email it to Linda Cottin at firstname.lastname@example.org.