Use a pressure washer at most, but do not wash with direct pressure. You can remove a lot of dirt using this chemical-free method as long as you are whoever you are. Do not use the high-pressure nozzle on brick surfaces. A pressure washer can even damage concrete, so test it in a less visible place before starting work all the way in the driveway.
Start in the top row at whatever psi you want. Follow that column down until you reach your machine's gpm, which is 2.5 gpm. Then follow that row to the left until you find the required nozzle size. That number is just the hole size.
When you go to look at the nozzles, there will be 2 other numbers at the beginning, depending on the degree pattern. That would give you about 1500 psi with your 2.5 gpm machine. You can adjust the pressure you exert with the rod by using the tips and moving the rod closer and further away from the concrete. Change the tips with a surface cleaner to properly adjust the pressure. Then treat it with a new layer of concrete.
Generally speaking, you'll need to connect the spray rod to the washer with a pressure hose and the washer to a water supply with a garden hose. When using a pressure washer, wear safety equipment to protect your eyes and ears, as well as shoes or boots with a closed toe. You can rent a pressure washer and accessories, such as a cleaner for entrances and surfaces, that are perfect for your project. If the spray from the pressure washer gets on your body, have the injury checked by a medical professional as soon as possible.
Pressure washing is a powerful cleaning method commonly used to revitalize surfaces, including concrete. If you want to try using a pressure washer but aren't ready to invest in your own, The Home Depot offers tool rentals. To calculate its cleaning power, or CP, multiply the maximum PSI rating of a pressure washer by its flow rate in GPM (CP = PSI x GPM)). The cleaning power of a pressure washer is determined by combining water pressure (measured in pounds per square inch, or PSI) with the amount of water used to clean a surface (measured in gallons per minute, or GPM).
