For general cleaning, pressure washing is a great cleaning option to remove stains and discoloration. But consider your stain type before you use a pressure washer. The use of a pressure washer on oil patches or set-in stains can make the stain worse, driving the stains deeper into the surface pores.
For grease and oil spots, use kitty litter as an absorbing agent by pouring a good amount over the stain and letting it sit on the stain overnight. The following morning, simply sweep away the kitty litter with your parking lot sweeper. If the stain persists, use some Tri-Sodium Phosphate (TSP) or a commercial degreaser. TSP can be quite dangerous, so use caution. Make sure to follow the directions on the bottle and scrub the product into the stain to break down the oil and rinse away with warm water.
A combination of TSP, bleach and baking soda is very effective to clean away grease on asphalt. Apply the compound directly to the stain, then use your side brooms to scrub it away.
Coca-Cola and dishwashing liquid combat grease spots on concrete very well. Simply pour the soda onto the stain, saturating it and leave it to soak overnight. Then scrub with warm water and dishwashing liquid the next day. Create a soapy lather with a nylon brush and the stain will simply lift away.
To remove mulch or leaf stains, apply some vinegar to the surface and scrub with a brush using circular motions and rinse the surface using a low-pressure rinse. If the stain persists, try mixing one capful of bleach with one gallon of warm water. Scrub the bleach solution on the stain using small circular motions. Allow the solution to sit on the stain for 30-minutes and wash away with warm water or a low-pressure rinse.
Submit your Schwarze Story here: Schwarze Stories