How to Clean a Flagstone or Bluestone Patio

A flagstone or bluestone patio adds functionality and beauty to a home landscape, so maintaining your patio pays multiple rewards. Sweeping or blowing leaves, dirt and debris off your patio is all it takes to keep your patio looking good most of the time. But sometimes it is necessary to do a more intensive cleaning job. The first step in cleaning a soiled or stained patio begins with assessing the nature of the dirt or stains.

  • Sweep your patio with a natural- or plastic-bristle brush or use a leaf blower to remove loose dirt and debris.
  • Attach a jet spray nozzle to your garden hose and wash down the patio with clear water.
  • Inspect your patio for remaining dirt or stains.

Embedded dirt requires a more intense cleaning. The best products to use depend upon the need.

Thoroughly Clean Patio Stones

Step 1 Prepare the Cleaning Solution

Mix 1 to 4 ounces of a neutral-pH stone cleaner per gallon of water or whatever ratio the manufacturer suggests. For large patios, mix several gallons of the solution in a large bucket.

Step 2 Apply Cleaning Solution to the Pavers

Mop the solution onto the pavers.

Step 3 Allow the Solution to Soak

Wait for two minutes before you scrub the pavers, giving the solution time to loosen dirt and stains.

Step 4 Scrub the Pavers

With a natural- or plastic-bristle brush, scrub the pavers. Agitate the brush to loosen dirt and stains.

Step 5 Rinse and Dry

Using your jet-spray nozzle on your hose, water-sweep the solution off the pavers.

Use a clean mop or wet vacuum cleaner to remove excess water.

Remove Biological Stains

Step 1 Prepare Soaking Solution

Add 1/2 cup of hydrogen peroxide or household ammonia to 1 gallon of water to remove biological stains such as algae, mildew or moss.

Step 2 Soak and Scrub

Mop the solution onto the affected area and allow it to soak for several minutes before scrubbing with a natural- or plastic-bristle brush.

Step 3 Rinse and Dry

Rinse the cleaning solution off the pavers with a jet-spray nozzle on your hose. Use a clean mop or wet vacuum cleaner to remove excess water.

Poultice Grease or Rust Stains

Stains are foreign matter absorbed into the stone. Removal of the stain is a reverse process, pulling the foreign matter out of the stone.

Step 1 Prepare Poultice Paste

Put poultice powder in a small, disposable plastic container and add enough distilled water to make a thick, spreadable paste, stirring with a plastic spoon and carefully following manufacturer's instructions.

Step 2 Wet and Spread

Wet the stained area and 2 to 3 inches beyond the stain with distilled water, then spread the poultice paste 1/4- to 1/2-inch thick on the wet area.

Step 3 Cover and Tape

Cover the poulticed area with plastic wrap and tape the edges of the plastic to the pavers. Leave the poultice in place for 24 to 48 hours.

Step 4 Uncover and Remove Poultice

Remove the plastic wrap and allow the poultice to dry completely before scraping the poultice material off the flagstones. Rinse the treated area with distilled water and wipe dry with a soft cloth.