Efflorescence: What Homeowners Should Know

If you’ve ever noticed a white, chalky substance on your basement walls, you’re not alone. It’s called efflorescence—and while it’s not dangerous, it can be a red flag.

What Is Efflorescence?

Efflorescence is a deposit of salt crystals that appear when water seeps through concrete or masonry and evaporates, leaving minerals behind. It looks like white powder or even fluffy deposits on walls or floors.

What Causes It?

• Water enters your basement through tiny cracks or porous concrete.

• As it evaporates, it brings minerals to the surface.

• The minerals dry and form a powdery coating.

Is It a Problem?

Efflorescence itself is harmless—but it’s a sign that moisture is getting in.

• It can signal poor drainage, leaky walls, or high humidity.

• Over time, moisture can cause mold, mildew, or structural damage.

What Can You Do?

• Check exterior drainage. Gutters, downspouts, and grading should direct water away from your foundation.

• Seal foundation cracks. Small cracks can let in water and should be sealed with waterproof products.

• Improve ventilation. A dehumidifier in the basement helps control moisture.

• Consider a professional inspection. A home inspector can identify moisture entry points and recommend solutions.

Bottom Line

Efflorescence is often overlooked, but it’s your home’s way of saying, “Hey, water’s getting in!” Catching and addressing it early can save you from bigger issues later on.