Excessive moisture on the surface of concrete as it dries leaves a powdery surface when it cures. Dusty concrete is a nuisance and it is prone to heavy scratch damage. Removing and reinstalling the concrete is not the only solution. Power washing and applying a concrete sealant is a do-it-yourself project that most homeowners can accomplish in a few hours time.
Use a wide-angle nozzle on a power washer to rinse the dusty concrete surface. The dial should be set to spray the water at 1,000 and 1,200 psi (pounds per square inch). Higher pressure can damage the concrete surface. Work in a sweeping motion to remove the dust accumulation from the top of the concrete.
Let the concrete completely dry before applying the sealant. Pour the sealant on a small area and begin smoothing it out using a long-handled squeegee. Use a push-pull motion to spread the sealant product and coat the concrete.
Even out the sealant into a thin layer over the entire concrete surface. Work in small sections at a time. Block off the area from foot or vehicle traffic for the length of the drying time recommended on the sealant label.
Reapply the sealant every four to five years for maximum benefit.
Askthebuilder.com offers some handy information regarding various types of concrete sealant. Pick a couple of days that are predicted to be good weather for your project.
Wear a dust mask when power-washing concrete. Follow the safety precautions on the sealant product label.