PSI (Pounds per Square Inch) measures water pressure—essentially how hard the water hits the surface that is being cleaned.

One of Amazon's Bestselling Pressure Washers Is 50% Off Right Now, and It's 'Powerful' Enough to Clean Concrete first ...

We used this model mostly on concrete, cleaning, degreasing, and blasting loose moss and dirt. If it can handle that, it can certainly handle typical pressure-washer-friendly surfaces like vinyl ...

Gas or electric pressure washer? 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 ...