What is Efflorescence and Should I be Worried?

People with crawl spaces often ask what is efflorescence, and should I be worried if it is present? Some homeowners are concerned that efflorescence could be a type of mold? Efflorescence is usually harmless, but it is an indication of a problem that could pose harm to you and your home.

So What is Efflorescence?

Efflorescence is a crystalline salt deposit that forms when water is present.

Efflorescence can be found in or on:

  • the block
  • brick
  • concrete
  • stone
  • or other building materials

It is usually found on foundation walls in crawl spaces with a water intrusion or flooding problem.

What Does Efflorescence Look Like?

Efflorescence has a white or grayish tint and consists of salt deposits that remain on the surface after the water evaporates from the foundation wall. It can be present on painted and non-painted foundation walls. It can also be on many building materials around your home, located outside the crawl space.

Is Efflorescence Mold?


Mold is a fungus, and efflorescence only occurs when moisture evaporates and leaves behind salt deposits.

Mold is a type of fungus that consists of small organisms found almost everywhere. And according to WEBMD, They can be black, white, orange, green, or purple. Efflorescence is typically white, yellow, or brown, but what we mostly see is white, which is why some mistake it for white mold.

But, efflorescence is not mold.

Can Efflorescence Cause Mold?

Remember, if efflorescence is present in your crawl space, then there is a significant chance of mold growth. As mentioned earlier, while efflorescence on a foundation is not mold, the accompanying moisture can cause humidity which can cause mold growth.

Damp Conditions Can Lead to Several Other Issues

Standing water or even moist air can also create an environment conducive to mice, snakes, wood rot fungus, termites, and other pests.

Contact Crawl Space Ninja for Foundation Waterproofing and Encapsulation

The takeaway here is that efflorescence is a sign of an active or past water intrusion issue. Make sure it is addressed by interior or exterior waterproofing and dehumidification to ensure the indoor air quality of your home is not affected by a damp crawl space.

Do you need help with controlling humidity in your home and you live in Alabama, Georgia, Delaware, North Carolina, South Carolina, Tennessee, or Kentucky? If so, please contact us to schedule your assessment.

Also, let us know in the comments below if you’d like to suggest a future blog post.

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