Worn Cement Slab Needs 2-Inch Topping

Question: My cement slab garage floor is starting to wear and show rough spots. Is there a way I can apply a topping layer to renew the surface?

Answer: You can top a slab, but you must be careful about getting the topping material too thin. The Portland Cement Assn. recommends that topping over hardened concrete not be less than 2 inches thick at any point.

To top a concrete slab, clean the surface with muriatic acid or concrete cleaner (available in paint and hardware stores). To ensure the topping bonds well, roughen the surface of any slab that has a shiny, smooth surface. Use a wire brush and full-strength muriatic acid to do this.

Next, mix a slurry of cement, sand and water and scrub this onto the surface with a throwaway scrub brush. This slurry acts as a primer to ensure a good bond between the slab and the topping. Apply the concrete topping mix on top of the slurry before the slurry starts to dry.

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