Homemade Flagstone Cleaner

Flagstone makes an elegant choice for a patio or walkway. In order to keep your flagstone looking nice, you need to keep it clean. While the idea of scrubbing rocks sounds funny, a little elbow grease will go a long way.

If you grill on your patio, you will need to clean more frequently, since grease spatters will mar the flagstone. Flagstone set in damp areas may grow moss, lichen or mildew. Homemade cleaners use common household products for safe, effective and environmentally friendly cleaning.

Basic Wash

Most of the debris on a flagstone patio can be removed with a powerful washing. You can spray the flagstone with a hose turned on full blast or with a power washer. If you don't own a power washer, you should be able to rent one from a home improvement centre near you. Power washing will strip away most films, moulds or mildews on your flagstone patio.

If you don't have access to a power washer, prepare a bucket of hot soapy water. Wash down the flagstone with your garden hose. Take a long-handled scrub brush and scrub back and forth with the soap solution, concentrating on any areas that are particularly soiled. When you've gone over the patio with the soap, wash everything off using your hose. If you see areas that are still soiled, repeat the soap scrub.


A vinegar cleaner is easy, sanitary and environmentally friendly. If your flagstone has mould or mildew on it, a vinegar cleaner will remove it without leaching chemicals into the stone. Vinegar works against oils and fats, important if you have a grill on your flagstone patio. To prepare a vinegar cleaner for your flagstone patio, mix white vinegar and water in a bucket using a 1:15 ratio, as recommended by The Flooring Lady. Use a scrub brush to work the solution into the patio. Allow the solution to penetrate the flagstone for at least five minutes before rinsing it off with water from a hose. If you find stubborn stains, repeat the process.

Boiling Water and Baking Soda

To remove moss or lichen from your flagstone patio, boiling water is a safe and easy home method. Boil a large pot of water. Pour the boiling water on the affected areas until the moss or lichen is thoroughly wet. Scrub the flagstone with a scrub brush. If you still have moss problems, sprinkle baking soda on the moss or other problem areas, then repeat the boiling water soak and scrub. After a few repetitions, your flagstone should be clean and free of moss and lichen. The boiling water soak is good for heavy stains and build-up of oil or other debris.