How to Clean Natural Stone

Life happens. While very little maintenance of your patio, walkway or driveway is required, it’s natural that some staining will appear over time. Barbecue spills, rust spots from patio furniture, bird droppings and oil stains can mar the surface of your natural stones. Fortunately, you can remove most stains with these helpful tips.

Try a softer touch first

Although Unilock natural stones have beauty and durability built right in, using gentle cleaning techniques first help keep their pristine appearance longer and also prevent unnecessary erosion of the joint sand. If you’re not satisfied with the results, you can move on to more powerful paver cleaning products.

First, assess the surface to determine the type of stains you’re dealing with. Sweep the area and spray it with clean water from a hose to clear away dirt and debris and reveal the stains. Check under the barbecue, patio furniture and planters – you may find dripped grease, smoke stains, rust marks, and leaf stains. The cleaning methods you use will depend on the type of stains present.

Grease stains – Scrub stains with a liquid detergent, such as dish soap. Squirt the soap directly on the stone, and scrub the area with a brush to break up the grease. Rinse with water. If the stain is still there, try an ammonia solution made with 1/2 cup of ammonia mixed with 1 gallon of water. Be sure to wear gloves and eye protection when using ammonia. Rinse the stone surface completely each time.

Organic stains (leaves, bird droppings, food) – Mix 1/2 cup of household bleach with 1 gallon of water. Be sure to wear gloves, eye protection when preparing, and using the bleach solution. Scrub the area with the solution. It will clean the stains and kill the organisms that can make them return. Mop up the excess bleach solution with clean cloths or rags, and rinse with clear water.

Oil stains from vehicles – If you discover an oil stain from a vehicle, it’s best to act quickly. Lightly dab (not rub) the stain with the rag or towels. You can try liquid dish soap or laundry detergent first. Apply the soap to the stain and allow to sit for 20-30 minutes. Then, gently scrub with a nylon bristle brush and rinse with hot water. Repeat as needed. If the oil stain has dried and absorbed into the paver, use a rag to soak up as much oil as possible. Apply a granular absorbing material to the area and let it sit for approximately six hours. Sweep the area and try to clean the stain with soap again.

When you need something stronger

Some stains, such as rust, limescale and efflorescence can be stubborn. When you need something stronger to do the job, try products that are specially designed for different types of stains.

Rust stains – If steel or iron furniture sits on areas that are exposed to the elements such as rain and snow for a long period of time, rust stains can appear. Removing rust stains on stones can be difficult. In this case, you will require a commercial product such as AcidClean. Follow the directions on the label. Make sure you test a small area first.

Efflorescence – Efflorescence is a whitish haze that appears on the surface of the stones. It is caused by naturally occurring salts in both the base materials and/or aggregates used to manufacture the stone. Efflorescence can be unsightly, but it does go away with time. If you don’t want to wait for nature to do its work, you can try a commercial efflorescence remover. Be sure to test an inconspicuous area first.

Stains from berries, tea, coffee and wine – You may need to take stronger action on these stains if they’ve seeped into the stones. Try BioClean to make food stains disappear. Conduct several small test areas according to the label instructions to determine surface color stability and desired results.

Choose the right product for the job

Not all cleaning products are suitable for all stones. Marble, limestone and travertine stones for example are acid-sensitive. To clean these, try using PowerClean, a fast-acting concentrated high-alkaline cleaner and degreaser. It is designed to remove most oil and grease, food stains, general dirt and mud, and light cement contamination on acid-sensitive surfaces. Just be sure to try it on an inconspicuous area first.

If you have stubborn stains on your natural stones, you have many options for making them disappear. Learn more about natural stone cleaning products or consult with an authorized Unilock contractor to help you bring their beauty back.