How to Remove Concrete Stains

Whether your driveway or patio was poured by yourself or a professional service, if the job was not "finished", you could end up with staining problems caused by everything from tree sap to car oil.

Remember, concrete is a porous substance. You can put a smooth finish on it, but that will not be enough to stop it from absorbing paints or other substances that are spilled on the surface. The best idea when pouring concrete on driveways, patios, or as pads for a garage or tool shed, is to give it a smooth finish and then seal it with a waterproofing. This gives you an impermeable surface that will allow for quick clean-ups when the car leaks or a paint can gets dropped.

If you didn't do this originally, it's not too late. You can put another thin layer down on top of your present cement, and seal it afterwards. But if what you have now for a concrete surface is already stained, you'll want to clean that up, first.

Your wisest course is to buy a commercial cleaner designed specifically for concrete. But in a pinch, you can try these tips.

For fresh spills, you'll want to soak up the extra. The best way to do that is to cover it with clay kitty litter, which is highly absorbent. In a workshop, you might have a bag of sawdust stored away. That will also do. Allow the litter or sawdust to set for a few hours, then scoop up and dispose of properly.

If the stain is something water soluble like latex paint, wet it down with some warm water and scrub with a nylon brush and plain laundry detergent, hosing off the surface as you go. When the stain has a grease or oil component, try covering it with the detergent and letting it set for 15 minutes before scrubbing. Small areas that are oil marks, may benefit from being covered with a grease-cutting dish detergent instead.

Other substances may be removed by scrubbing with a dilution of bleach, as recommended on the bottle for cleaning. Tri-sodium phosphate is also useful, in a dilution of one cup per gallon of warm water. Wet the spot, let sit for 15 minutes and then scrub.