The beauty of decorative concrete floors was only possible if the floors were poured when the house was built. However, advances in concrete technology have made it possible to give existing floors a coating that looks and behaves like concrete. With some products, it is even possible to pour these concrete-like floors over wooden flooring.
Choose the right products for the job. Make sure the topping can be used with wood. Several manufacturers produce toppings that are recommended for use only over a concrete subfloor. At lease one manufacturer, Colormaker Floors, produces a topping that can be used over wood. Make sure the cement board is compatible with the topping and the wood subfloor. Hardiplank works well for this kind of project. Choose the 1/2 inch thickness.
Screw the Hardiplank panels to the floor. Use one screw at each point marked on the panel.
Use mesh tape to cover the seams between the panels. Then trowel a thinset mortar over the tape. Let the mortar dry for 24 hours.
Use a garden sprayer to apply the primer. Follow the manufacturer’s directions. Let the primer dry completely. Apply a second coat as needed.
Prepare the topping according to the manufacturer specifications. Work in one small area at a time. You should be able to reach across the area easily. Start in the corner opposite the doorway and work backwards toward the door.
Pour a few cupfuls of the topping onto the floor. Immediately smooth the product with the floor gauge roller. Work as quickly as possible.
Let the topping mixture stiffen. Then trowel it smooth with the pool trowel. Start in the far corner of the room and work backwards toward the door. Wear the knee boards so that you don’t leave dents in the topping. Smooth out your tracks as you back out of the room.
Let the topping dry for at least 24 hours. If you want to color the floor, apply two coats of acid stain according to the manufacturer’s directions. It will take an hour or so for the color to develop.
Neutralize the acid as the manufacturer recommends. Rinse with water several times. Use a shop vacuum to remove all the water. Let the floor dry completely.
Apply a concrete sealer to the floor, and let it dry completely. You can then wax the floor if you choose.
Wear rubber gloves when working with concrete.
Wear a disposable respirator and goggles when working with acid stains. If you get wet concrete on your skin, wash it off promptly.