How to Care for Unsealed Concrete

Outdoors, wash unsealed concrete with 1 cup of trisodium phosphate (TSP) or powdered laundry detergent in 1 gallon of water. (You can find TSP at your local hardware store.) Scrub with a long-handled scrub brush or use a pressure washer. Use caution when using pressure washers. Very high-pressure water can cause old concrete to crack or break and can also cause serious injuries.

Absorb fresh motor-oil stains with regular non clumping kitty litter. Commercial driveway cleansers may help remove old oil stains. Remove mildew stains with bleach, and remove white, crystallized efflorescence with muriatic acid. Scrub with a long-handled scrub brush and rinse well.

Consider sealing concrete to protect it from stains. Clean the surface thoroughly, then apply concrete sealer with a long-handled paint roller according to the manufacturer’s instructions. Reseal concrete every 2–3 years.

To repair minor cracks in concrete, use masonry crack filler. To fix larger cracks, use a hammer and chisel to undercut the crack, which makes it wider at the bottom than at the top. Fill the crack with patching mortar or vinyl patching compound. Working with concrete can be tricky, so if you’re at all uneasy, hire a professional to do the job.