How To Remove Efflorescence From Stone

How To Remove Efflorescence From Stone


When the weather is right and the earth seems to be coming back to life, we start to find more and more reasons to spend our time outdoors. After a long winter, some might decide to use the patio or deck to host a get-together or to simply soak up the weather. But maybe the tough wetter seasons have changed something in the appearance of your natural-stone patio or walkway. You might find that the once clean surface now has what seems to be a greyish white powdery substance covering it. This could be efflorescence.


Its French origin means “to flower out” but efflorescence emphasizes anything but beauty. While the main issue has to do with the appearance of natural stone, its need for moisture can be an indication of a more serious problem. In some rare cases, the accumulation of salt caused by efflorescence can lead to masonry damage as it chips away at the surface. In extreme cases, its persistence could even lead to mold. Knowing how to remove efflorescence is essential to keep these problems at bay and your natural stone, or concrete and pavers, looking wonderful.

What is Efflorescence?

In short, efflorescence occurs when standing water or excess moisture is left to dry on natural stone. This creates salt deposits on the surface that appear as white film or powder.  While efflorescence is primarily an aesthetic problem, it shouldn’t affect the structural performance of the stone unless an excessive amount of salt deposits is ultimately collected. Due to its need for excess moisture, efflorescence could potentially be an indication of an even bigger issue with its surrounding areas. It could mean that an unseen leak is causing water to drip nearby. There’s also the chance that the material could have been left out to absorb moisture during construction, and this could lead to various building installation problems. Whatever the cause, knowing how to remove efflorescence can help protect you against a negative outcome.

The Cause of Efflorescence

While we are addressing outdoor efflorescence, it does not shy away from becoming a problem indoors. Being able to know the cause of it can help you be on the lookout for its presence on any surface. In order for efflorescence to occur, two key ingredients need to be present – moisture and water-soluble salt, or salt that has the ability to dissolve in water. As moisture transforms the salt into a soluble solution, it travels through the natural stone and onto the surface. This salt then crystallizes as moisture evaporates, resulting in efflorescence.

Efflorescence Seasons

Because moisture effects where soluble salt appears, efflorescence is typically a seasonal problem. Since winter tends to bring rain, snow, and sleet, efflorescence is known to dramatically increase during this season. But it that won’t stop it from showing up in the spring, summer or fall. A high level of moisture in any season could potentially lead to an increase in efflorescence.

Distinguishing Efflorescence

Learning to identify efflorescence is the first step in knowing how to treat it. It’s good to keep in mind that efflorescence is usually found on unsealed surfaces. Its’ physical characteristics are usually white and powdery. This is important when differentiating efflorescence from your average stain, which usually comes in various colors. It’s also important to keep in mind that water can become an important factor when distinguishing efflorescence from calcium deposits. Although both are very similar in appearance, efflorescence will become darker when splashed with water since it rests on the surface. While calcium deposits are a lot denser and form right below the surface material, water will ultimately have little to no effect.

An Efflorescence Remover

Removing efflorescence is essential for the care of your outdoor natural stone. Granite Gold Outdoor Stone Cleaner® comes in a unique packaging that attaches directly to your hose and is made to rinse and clean your natural-stone patio or walkway to free it of efflorescence. Our Outdoor Stone Cleaner is made to clean patios, decks, driveways and so much more. Use a stiff nylon brush to agitate dirt, grime as well as efflorescence. Granite Gold Sealer® will help slow efflorescence from returning and provide extra protection against stains, etches and soil buildup. Enjoy the true beauty of the outdoors as you lean on the expertise of Granite Gold to care for your natural stone.


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