Skip to content

Flagstone Pressure Washing

Similar to pressure washing concrete sidewalks and concrete patios, you want to use an environmentally friendly detergent to remove stains on flagstone and bring back the original color of the stone. A combination of bleach, water, and soap normally does the trick. If you are doing research on the Internet you may come across some pressure washing contractors that talk about muriatic acid or hydrocloric acid. We try to use acids as little as possible in our line of work especially with flagstone walkways and patios, not because it would not get the job done but because it simply is not necessary. Additionally, acids can harm nearby landscaping.

What you Need to Know about Flagstone

Flagstone is a sedimentary rock which consists of layers upon layers of sheets of sandstone. Over time the top layers can weaken because of erosion from rain and snow. It is for this reason that you should not use full pressure with your powerwasher. Holding the tip of your gun close to the stone can blast those layers off the flagstone. We suggest using a wheel-mounted flatwork machine on low pressure for patios and walkways. If you have a groutless flagstone walkway, one in which individual stones are spaced independently from one another, we recommend using a scrub brush and a low pressure gun.

Flagstone Cleaning Tips

If you are planning to clean flagstone on your own you should be wary of a few things. First, when using a pressure washer on flagstone the water being used exits with such a force that you can create flakes, chips, popouts and even concrete spalls. It is not as simple as putting the setting on full blast an inch away from the surface and going at it. With flagstone the majority of the work is done by the cleaning agents and hot water you use. Hot water works best so make sure you hire a contractor equipped with a hot water machine.

Wheel-mounted Flatwork Machine

Wheel-mounted Machine

While you do not necessarily need a wheel-mounted flat work machine like you can see in the photo to the right we highly recommend using one if available. In addition to getting larger areas completed in just a fraction of the time, wheel-mounted flatwork machines guarantee that the entire area is cleaned by a nozzle from the same distance. When using a powerwashing gun you walk and sway the nozzle a couple feet at a time. When doing so your nozzle may be 6 inches from the concrete to your right or left and 4 inches from the flagstone at your feet. A wheel mounted machine has multiple nozzles that are set in place a few inches above the surface so you will have the same finish throughout.

I often compare cleaning an area of flagstone to mowing grass. Sure, you can use a weedwacker to clean any size grass area but even the most skilled person will have some areas of grass higher than others. A lawn mower is quicker and guarantees all the grass will be the same length. J&J Power Wash offers commercial flagstone pressure washing services. No matter how dirty your flagstone is we can help. To set up a free estimate call us at 215-703-8306 or fill out our online form. Click on the images below to enlarge them or visit our portfolio page for additional before and after pictures.

Time Lapsed Video

Before & After Pictures

Flagstone Cleaning BeforeFlagstone Cleaning AfterFlagstone Patio BeforeFlagstone Patio Afterflagstone walkway beforeflagstone walkway afterFlagstone Pressure Washing Flagstone Powerwashing Flagstone Power Washing
Flagstone Patio Before PowerwashingFlagstone Patio After Powerwashing

Serving the Greater Philadelphia and South Jersey Areas