Is there a “whitish cloud” covering your beautiful new patio? Before you pick up the phone to complain, we urge you to read this. The white haze you’re seeing is called paver efflorescence and while it may be ruining the appearance of your patio, paver efflorescence is completely natural and is not damaging your pavers in any way. Paver efflorescence, also known as ‘calcium hydroxide’ or ‘free lime’ can occur a few weeks after the installation of your pavers and is much more common than you may believe.
While paver efflorescence is both a regular occurrence and is completely natural, we completely understand why most want to rid their patio of this “white discoloration.” You wanted a beautiful patio- not a patio covered in efflorescence. The following article by Kurt Glave will help you to better understand the science behind paver efflorescence as well as provide you with a solution to restoring your patio back to its original coloring.
Efflor – What? Efflorescence
What is it?
Efflorescence is a whitish haze that appears on the surface of concrete pavers within a few weeks or months of installation. Efflorescence may also be referred to as calcium hydroxide or free lime. Efflorescence is a completely natural occurrence. It usually occurs in random areas throughout all types of concrete pavers. However, it may appear more pronounced on dark colored pavers. But don’t worry. Despite the fact that it gives pavers the appearance of fading, it does not affect the structural quality of the pavers.
Why does it happen?
All concrete products contain cement. As the cement hydrates, it produces lime or water soluble salts, such as calcium hydroxide. The calcium hydroxide is soluble in water and therefore migrates to the surface of the concrete pavers through capillary action. When the calcium hydroxide reaches the surface of the pavers, a chemical reaction occurs with the carbon dioxide in the air. As it reacts with the carbon dioxide, the calcium hydroxide forms a water insoluble calcium carbonate. The calcium carbonate creates the whitish haze on the surface of the concrete pavers. As the moisture evaporates off the surface of the pavers, the whitish haze becomes more pronounced. And as naturally as the efflorescence appeared, it will fade.
Efflorescence will most likely disappear within the first year of installation… Most concrete paver manufacturers have attempted to control the problem of efflorescence by using an admixture in their products. However, no manufacturer has completely eliminated the problem. Therefore, most contractors resort to the use of commercial efflorescence cleaners. Most cleaners will effectively reduce the whitish haze on the paver caused by efflorescence, but only if used properly.
Here are a few simple tips for working with efflorescence cleaners:
1). Improper cleaning can result in damage and discoloration of the pavers and/or personal injury so always make sure that the manufacturers’ recommended application procedures are followed;
2). Always test the cleaner in a small inconspicuous area before cleaning the entire paver surface;
3). Most efflorescence cleaners contain acid or detergents, so protective measures must always be taken before handling the cleaner (see manufacturer’s directions);
4). Remember that efflorescence will continue to reappear until the calcium hydroxide has time to exhaust itself, so more than one application of cleaner may be necessary.
Now that you have a better understanding of what efflorescence is, it’s time to eliminate it! Camosse Masonry Supply in central Massachusetts carries a variety of cleaners to rid your pavers of efflorescence. If you are having a problem with paver efflorescence, we invite you to explore the cleaners that we supply. Don’t call your contractor to complain about efflorescence, call Camosse Masonry Supply instead. We’ll help you with any questions you have regarding paver efflorescence and also have the knowledge and know-how to assist you with any other masonry issue you may have.