| Ever get a telephone call from an irate customer | | | | Efflorescence will most likely disappear within the |
| telling you that the pavers you just installed are | | | | first year of installation. So, what can you do for |
| defective or fading because the pavers are | | | | that irate customer who isn't willing to wait for |
| turning white? Ever wonder yourself what causes | | | | the efflorescence to fade? Most concrete paver |
| the white appearance on pavers? It's called | | | | manufacturers have attempted to control the |
| EFFLORESCENCE. | | | | problem of efflorescence by using an admixture in |
| What is it? | | | | their products. However, no manufacturer has |
| Efflorescence is a whitish haze that appears on | | | | completely eliminated the problem. Therefore, |
| the surface of concrete pavers within a few | | | | most contractors resort to the use of |
| weeks or months of installation. Efflorescence | | | | commercial efflorescence cleaners. Most cleaners |
| may also be referred to as calcium hydroxide or | | | | will effectively reduce the whitish haze on the |
| free lime. Efflorescence is a completely natural | | | | paver caused by efflorescence, but only if used |
| occurrence. It usually occurs in random areas | | | | properly. |
| throughout all types of concrete pavers. | | | | Here are a few simple tips for working with |
| However, it may appear more pronounced on | | | | efflorescence cleaners: |
| dark colored pavers. But don't worry. Despite the | | | | 1). Improper cleaning can result in damage and |
| fact that it gives pavers the appearance of | | | | discoloration of the pavers and/or personal injury |
| fading, it does not affect the structural quality of | | | | so always make sure that the manufacturers' |
| the pavers. | | | | recommended application procedures are followed; |
| Why does it happen? | | | | 2). Always test the cleaner in a small |
| All concrete products contain cement. As the | | | | inconspicuous area before cleaning the entire |
| cement hydrates, it produces lime or water | | | | paver surface; |
| soluble salts, such as calcium hydroxide. The | | | | 3). Most efflorescence cleaners contain acid or |
| calcium hydroxide is soluble in water and | | | | detergents, so protective measures must always |
| therefore migrates to the surface of the | | | | be taken before handling the cleaner (see |
| concrete pavers through capillary action. When | | | | manufacturer's directions); |
| the calcium hydroxide reaches the surface of the | | | | 4). Remember that efflorescence will continue to |
| pavers, a chemical reaction occurs with the | | | | reappear until the calcium hydroxide has time to |
| carbon dioxide in the air. As it reacts with the | | | | exhaust itself, so more than one application of |
| carbon dioxide, the calcium hydroxide forms a | | | | cleaner may be necessary. |
| water insoluble calcium carbonate. The calcium | | | | So despite how unmanageable your customers |
| carbonate creates the whitish haze on the | | | | may become after efflorescence appears on their |
| surface of the concrete pavers. As the moisture | | | | pavers, remember that efflorescence, itself, is |
| evaporates off the surface of the pavers, the | | | | manageable. Inform your customers of their |
| whitish haze becomes more pronounced. And as | | | | options for controlling efflorescence and allow |
| naturally as the efflorescence appeared, it will | | | | them to make the decision as to how to manage |
| fade. | | | | it. |