How to Clean the Concrete Off a Stone Patio

Stone is one of the most popular materials for patio floors; however, the installation process can prove to be a messy one. It is common for stray amounts of concrete to find their way to the surfaces of the stone either during or after installation. Although concrete is mostly a permanent material, it can be cleaned off the patio with the right materials and tools.

Things You'll Need

• Eye protection
• Breathing mask
• Rubber gloves
• Wire brush
• Muriatic acid
• Lime (or baking soda)
• 5 gallon buckets
• Water hose
• Large sponge
• Masonry hammer and chisel

Instructions

Scrubbing

1. Rinse the concrete with water, and put on eye protection, breathing mask and rubber gloves.

2. Fill a 5-gallon bucket about half full with water, then carefully pour in about a quart of muriatic acid; try to avoid splashing.

3. Dump the wire brush into the diluted acid, and begin to scrub any concrete deposits from the stone surfaces; the solution will fizz as it eats away the concrete material.

4. Fill another 5-gallon bucket with clean water.

5. Clean the acid-scrubbed surface using the sponge and clean water, returning any liquid to the first acid mix bucket, and repeat as necessary.

Clean-up

1. Slowly stir generous amounts of lime or baking soda into each bucket; both lime and baking soda will neutralize the acidity of the muriatic acid.

2. Stir both buckets until they have stopped fizzing; this is a sign that any chemical reactions are finished, and the liquid is neutralized.

3. Dispose of the fluids by pouring them out into dirt or sand; it is best to pour this mixture into an area bare of direct plant life, because even though the mixture is neutral, it is still not good for plants.

4. Rinse the stonework with fresh water using a garden hose.

Tips & Warnings

• For large deposits of concrete, it may prove easier to chip away with a masonry hammer and chisel before scrubbing with acid.

References

• "Cleaning Stone and Masonry"; James R. Clifton;c 1986