What Causes Efflorescence?

It might be easy to discover, but the word “efflorescence” can be confusing to many people. Does efflorescence mean the basement leaks? Can you just wipe it off? Does it mean that something bad is happening to your home?

The good news is, efflorescence is less complicated than the name might indicate. Efflorescence requires these three distinct components to form.


Efflorescence starts with salt. The wall on which efflorescence forms needs to have some sort of salt that water can then dissolve.

Most home foundations, basements and crawl spaces are made of concrete or brick. It’s most common for concrete or brick to be made with limestone, clay or sand. These natural materials tend to have a wide variety of minerals, including salt.


The next ingredient is water. Efflorescence requires that some sort of water encounter the salt in these bricks to dissolve it. That means when you see efflorescence in your basement, crawl space or foundation, there’s some sort of water there.

There may be water outside your basement foundation from poor grading, heavy rain or groundwater. You may have a plumbing leak or flood. Regardless of the reason, hydrostatic pressure can push the moisture into your basement.

An Entry Point

Lastly, the water needs to be able to get through the walls into your basement, crawl space or foundation. Solidly built walls don’t have any cracks in them, which means that even if water exists on the outside of the wall, it won’t create efflorescence on the inside.

However, wall cracks, foundation cracks, pores in the concrete and even the floor-wall joint in your basement can create that entry point. When you see efflorescence, it means water is leaking into the area where you see it.

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