A concrete patio is a lovely addition to any backyard. When a concrete patio is new and stain free it looks beautiful. Once your concrete patio starts to age and accumulate stains, it's not so nice anymore. Most of the time, a concrete patio will clean up well when you scrub it with ordinary dish soap, a stiff bristle broom and a hose. More difficult stains require specific treatments.
Oil and grease stains can be removed from a concrete patio by first apply kitty litter to the spill. Allow the kitty litter to absorb the excess oil and grease. Let on overnight. Sweep up the kitty litter. Apply a degreaser which can be purchased at an auto parts store, leave on as per the directions on the can or bottle.
For splattered or spilled paint on your concrete patio soak a rag with paint remover, place on top of the stain, leave on for an hour or so. The paint will begin to soften and can be scraped off. Repeat until the paint is gone
If your concrete patio has a rust stain use a mixture of 6 parts glycerine, 6 parts warm water and 1 part ammonium citrate or sodium citrate. Glycerine and sodium citrate are available at the pharmacy. Scrub the rust stain with the mixture and a stiff brush, and rinse well with plain water.
Some concrete patios will develop black smoke stains from the grill. To clean these stains, scrub the concrete with a dilute glycerine and trichloroethylene poultice. Rinse well with plain water.
Some concrete patios will get a white powdery area which is called "efflorescence." It is caused by the moisture in the concrete dissolves the salts in the concrete. First try scrubbing with a stiff bristled broom and plain water. If this doesn't work, use a very weak solution of muriatic acid, scrub with a stiff brush. Rinse very well with water.