How much concrete do you want to clean and how often? For smaller areas, a consumer-friendly electric machine may work well, only it will take longer. There is also less chance of damaging the concrete: if care is not taken, the excess pressure exerted by a large machine that runs on gas can cause lines to form in the concrete. Concrete driveways (and walkways) can easily withstand heavy cleaning without leaving marks. Usually, a thinner nozzle will be more effective to clean greasy stains.
For mold or mildew, use lower pressure and first cover the surface with foam. Those that generate a higher pressure level (measured in pounds per square inch) receive a higher score than those with a lower outlet pressure. A powerful pressure washer is the best option for restoring the appearance of concrete, but not all pressure washers are made the same way. So when should the pressure washer be disassembled and when would a scrubbing brush and garden hose be enough? We've asked the automatic cleaning experts who oversee the ratings of our pressure washers to give their opinion on a variety of common surfaces. I suspect that the ratings of pressure washers are often as optimistic and misleading as those used for vacuum cleaners, but the price is quite typical of an electric pressure washer for homeowners.
