Mold and mildew get a lot of street cred for looking so icky. An army of experienced pressure washers, however, would be able tell you about one of the lesser known culprits out there: Efflorescence. This sometimes powdery white crust observable on surfaces like stone, concrete, brick, and mortar can be a fairly delicate thing to deal with. To win a battle, we must know our enemies well. So let us get to know this troublemaker better.


Origins of the Term

If the name of this culprit sounds pretty, that’s because it might remind you of words like “effervescence” and “floral.” As a matter of fact, the origin of the word efflorescence has a lot to do with the Latin word florescere, which means “to blossom.” In a way, the chemical context is fitting for the phenomenon since the white crust is a result of crystallization—something reminiscent of the bloom of a flower.

How Does Efflorescence Happen?

Efflorescence occurs due to the deposition of soluble salts and minerals that are embedded within a substrate. When the moisture evaporates, it migrates from within the substrate to the surface, and brings along with it the present salts and minerals. When the moisture wears off, the salts and minerals stay deposited on the surface. The more salts and minerals there are, the more noticeable they would be on the surface of the substrate.

Sometimes you can even make out a face…

Is Efflorescence Dangerous?

Mold spores can trigger asthma, and rusty nails can cause tetanus. So what about efflorescence? Well, let’s think about it. If efflorescence is noticeable, it is a clue that the substrate may contain excess water. And because a damp place can make for favorite breeding grounds for mold and mildew, the dampness alone would presumably be a valid cause for concern. Efflorescence may also indicate that there are water intrusion issues or construction defects in a building. Be sure to consult a professional to identify the exact problems. Humidity can slow down the evaporation of the substrate’s moisture, which means paying extra attention is advisable if you happen live in places with high-humidity levels.

Yep. That’s a whole lot of “Nope.”

What Is the Solution?

Adept pressure washing can remove efflorescence. Some recommend using acid solutions, but even while exercising caution, these substances can cause many accidents. The easy and solid way to take care of efflorescence is to enlist professionals. Oh, and here’s a pro tip: Drying off the water is important, since reabsorbed crystals can reappear from the substrate later.


Eliminating efflorescence may take time and patience, but is crucial to the integrity of a building. And trying to take down this culprit oneself is not the answer. Attack the problem at its core by letting experts give skillful help. Contact Oceanside Pressure Washing and Roof Cleaning today!