Cleaning Stone

2019 may have just began, but spring is right around the corner. For those of us who are dying to get back out there and enjoy warm weather in our outdoor spaces, now is the time for us to start cleaning. Obviously the garden beds need to be cleaned out, leaves raked, lawns blown, but when was the last time you cleaned your hardscapes? Stone patios, paver walkways, and even concrete driveways need regular maintenance to keep them looking their best. And for general safety.

Did anyone else bust their butt this week because their driveway was wet and had a thick layer of grime? No? Just me?

First you need to determine what kind of stone you have before you jump the gun and break out the pressure washer. Do you have natural stone or manufactured? Pavers or solid concrete?

If you have natural stone or a concrete slab, a pressure washer might be the way to go. If you have manufactured stone, don’t even think about it. Manufactured stone is basically a special concrete mix poured into several dozen unique molds and painted in shades of rock. Now, while this cuts down on the cost of stone and labor, you do have to baby manufactured stone once its installed. A pressure washer will strip the color off these stones at best, at worst they will crack and fall to pieces. Regardless, it will have to be replaced and installing manufactured stone twice does not make it cheaper than real stone.

You can see in the picture above where bleach ate thru the paint layer, leaving it discolored . So for manufactured stone, start with spraying it off with water. If still not clean, find some mild detergent or soap and a scrub brush (not a wire one), this will take care of the rest. Just remember, no pressure washer, no acidic cleaners, and no bleach on manufactured stone.

For pavers, use a pressure washer at your own risk. While a pressure washer can and will clean your pavers, it will also happily blast the sand out from between the joints. So unless you are a seasoned pressure washing pro or are ready to re-joint your pavers, try soap and water first. If that doesn’t work, pavers can handle more heavy duty cleaners but remember to follow all safety instructions or call a professional.

The majority of natural stones used for exterior  hardscapes are pretty tough, they have to be to stand up to mother nature. But it’s always a good idea to ask how to clean the stones you’ve chosen before they are installed. Can this be pressure washed or will that cause the stones to chip? Can a diluted bleach mixture be used to get rid of mold or algae? Can I use acidic cleaners on this stone? Nine times out of ten, the answer for all these questions will be yes but it’s still important to ask.

As for concrete, you can just break out that pressure washer.


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