Most electric pressure washers create 1300-1700 pounds per square inch of pressure (PSI) with a water flow of 1.5 gallons per minute (GPM), but experienced contractors recommend between 2000 and 3000 PSI and a flow of at least 2.5 GPM to clean dirty concrete effectively.
There's no doubt that electric pressure washers from 1,300 to 2,300 psi can wash a concrete driveway, but it'll take longer. If you have a large driveway with lots of stains, you'll want more power to do the job faster.
MEDIUM-DUTY pressure washers in the 1,800 to 2,000 PSI range can tackle bigger projects like large SUV's, RV's, siding and fencing, decks, garage floors and driveways.
Concrete cleaning calls for powerful pressure washers featuring high pressure levels of 3000 PSI. However, if you will be using the power cleaner to maintain a range of surfaces in addition to concrete, choose one with adjustable pressure levels and set it to about 3000 PSI when you need to clean concrete.
Concrete and asphalt require more cleaning power. You'll want to use the turbo nozzle on the 1600 PSI for hard-to-clean driveways, sidewalks, and patios as well as brick paving. For wood decks and painted surfaces, switch to the gentler 40-degree nozzle.
Light Duty 1500-1900 PSI
For regular maintenance and light household cleaning jobs, a light-duty pressure washer will do. These feature PSI ranging from 1500 to 1900 and would be enough to get rid of dirt and mild stains.
Any machine capable of producing at least 1,500 pounds per square inch (psi) of pressure can clean concrete, but the work will go much faster if you choose a model producing 2,500 to 3,000 psi, like the gas-powered option below.
For instance, a light layer of dirt or dust may only require a PSI of 1,500 to 2,000, while a thick layer of oil or grease may require a PSI of 3,500 or higher to remove.
This 1600 psi 1.2 GPM electric pressure washer, as explained earlier, generates 1,600 Pounds Per Square Inch (which is in the recommended pressure range), and 1.2 Gallons Per Minute (ideal for washing cars, house exteriors, fences, garage floors, etc…).
The quick answer is yes, power washing can degrade a concrete surface.
The RYOBI 1800 PSI 1.2 GPM Electric Pressure Washer is the perfect powerful yet portable option to get the job done. This pressure washer is ideal for light duty applications like cleaning small driveways, sidewalks, decks, windows, patio furniture, campers, bikes, boats, and many other recreational applications.
If you want to clean your driveway quickly and efficiently, use a pressure washer of at least 3100 PSI. Using pressure washers with pressures ranging from 1000 to 2300 PSI will also help you clean your driveway, but it will take a long time.
Although many electric pressure washers produce a pressure of about 1900 psi, you should only use a water pressure of 1500 psi or lower on your car. You'll need to look for a low-pressure machine that's a bit less aggressive than the standard.
Choosing a Pressure Washer
Vinyl siding can withstand a powerful gas pressure washer (2,500-3,000 psi). Aluminum, stucco or soft-grain wood homes will do better with a less powerful washer (about 1,200-1,500 psi). Determine whether you will rent or buy your machine.
The typical concrete strength used for a driveway is in the 3000 psi to 4000 psi range, although temperate areas of the country may use lower strengths. Contractors, when ordering ready mixed concrete, should advise the producer of the intended use for the concrete.
Oil leaks, blood, and sticky residues can absorb and result in stubborn stains. However, using a driveway sealant after pressure washing can help prevent these stains from becoming permanent features in your driveway.
PSI Pressure range for Different Surfaces
Different surfaces require different levels of PSI pressure. Generally, for most residential uses, an electric pressure washer (less than 2000 PSI) will suffice. Soft surfaces, such as decks and siding, usually require more cleaning power than harder surfaces such as driveways.
Medium Duty: Medium-duty pressure washers generate between 1900 and 2788 PSI, typically at 1 to 3 GPM. Best for home and shop use, these sturdier, more powerful units make it easy to clean everything from exterior siding and fences to patios and decks.
Generally, you'll want your concrete driveway pressure washed at least once a year. This lets you treat sunbaked dirt, grime buildup, and stubborn oil stains, making regular cleaning in between professional washes much more manageable. Of course, you can always schedule extra pressure washing services as needed.
What are Typical Specifications for a Quality Sidewalk? Concrete for sidewalk slabs must consist of 3500 to 4000 PSI, a combination of 3/4 blend of sand, stone and cement and also 6 to 7% air included in the mix. An expansion joint should be placed no less than approximately every 25 to 30 linear feet.
However, in general, a psi of 3000-4000 is commonly used for residential driveways.
For light-duty tasks such as washing a car or cleaning a barbecue grill, a pressure washer with 1,000 to 1,750 psi and 1.4 to 1.6 gpm (1,400 to 2,800 ECUs) will probably do the job.
You can power wash concrete all year as long as the temperature is about 40 degrees Fahrenheit. Most homeowners and businesses prefer to do it in the spring or summer to reduce the spread and growth of algae and mold. It also reduces pollen, which can affect allergies.
For most cars, a psi between 1200 and 2200 is recommended. This range provides enough cleaning power to remove dirt and grime without damaging the car's paint or delicate surfaces.