It can be just a white powder on your concrete, salt-like crystals, white fuzzy stuff, or what looks like white stalactites growing on your concrete wall. These white deposits happen when water is drawn out of a cementious material: it is called efflorescence. It is a scientific reaction.

Is efflorescence a serious problem?

Ultimately, efflorescence itself isn’t dangerous. However, it can lead to potential moisture problems that can cause structural damage to building materials. That means if you find efflorescence in the basement or on concrete and other structures, it’s important to take action.

How do you fix efflorescence in concrete?

The easiest step to remove efflorescence is to wash the wall and scrub the area to see if the stains go away. You will need to use only clear water to avoid worsening the situation. The sooner the better, as time will be against you if you are trying to remove these stains.

What is the white powder coming out of concrete?


Efflorescence is the white powdery substance on the surfaces of unsealed concrete and the white blush seen with sealed floors. Efflorescence is caused by vapor migrating through the slab bringing soluble salts to the surface of the concrete.

What causes efflorescence on concrete?

Efflorescence in concrete is a whitish coloured powdered deposition of salts on the concrete surface that is formed due to evaporation of water from the concrete. It is caused when water soluble salts are present in the concrete material, which comes on to the surface while evaporation of water from the concrete.

Does efflorescence go away by itself?

Yes. Although efflorescence will eventually go away naturally, there are commercial cleaners available that are specifically formulated to remove efflorescence from the surface of the concrete pavers.

Can you get rid of efflorescence?

In general, most efflorescence can be removed by dry-brushing followed by flushing with clean water. If brushing is not satisfactory, it may be necessary to use a very light (brush) sandblasting to remove the deposits.

How do you stop efflorescence from coming back?

The way to stop efflorescence from coming back is to interfere with its three necessary conditions: water soluble salts in the wall; a path for water to get into the wall and dissolve those salts; and a path for that water to reach the wall’s surface and deposit the dissolved salts.

Does vinegar remove efflorescence?

Vinegar and water solution—Efflorescence can be removed by using a dilute solution of household white vinegar and water. A vinegar and water solution is relatively inexpensive, non-toxic, and easy to obtain, mix and apply. Dilution ratio is 20–50% vinegar in water by volume.

Does sealing stop efflorescence?

Sealing masonry surfaces
The best protection against efflorescence and water damage is to use a penetrating sealer to make the surface entirely waterproof. The products we recommend using are a masonry sealer such as Resistain or Shower Plug.

What does efflorescence on concrete look like?

Concrete efflorescence is the appearance of white salt deposits on or near the surface of concrete causing a change in appearance. Efflorescence is the phenomenon that occurs when salt in concrete or groundwater is deposited as an unattractive white powder or stain on the surface of a wall, floor, driveway or path.

Can I paint over efflorescence?

Efflorescence appears as a result of salt being pushed to the surface of masonry. It’s a painting issue that’s easily overcome by the use of Zinsser Watertite®.

Is efflorescence harmful to humans?

It’s a type of salt deposit caused by salty water which seeps through concrete, brick or stone. When the water evaporates, it leaves behind a white crystalline substance that looks like white mould. Unlike white mould though, efflorescence does not pose any health risks and won’t grow or spread.

How much does it cost to remove efflorescence?

A handyman or house cleaning service will charge $143 to remove efflorescence from a 150-square-foot area, which includes the labor and material. You can remove the substance for $20, the cost of a clear water sealer, and save 86 percent.

What does efflorescence look like?

Efflorescence is a crystalline deposit of salts often seen on brick, concrete, paving stones, stucco, or other building surfaces. It occurs when water leaves behind salt deposits on or in the masonry surface. It has a white or grey tint and can also appear as a powdery substance on floors or walls.

What is the white powder on my concrete wall?

Efflorescence is actually a harmless crystallized mineral salt that has formed on your basement walls over time. It will generally look like a white, powdery substance. It’s also commonly found on floors.

Can mold look like crystals?

Mold is an organic growth and certainly does not look like crystals.

Does efflorescence mean the basement leaks?

Does Efflorescence Mean the Basement Has a Leak? Efflorescence requires the appearance of water from somewhere in the basement. Most commonly, this water does come from a leak, typically through cracks in the walls or floor. However, you might also have an internal leak through your plumbing system.

What is white fluffy stuff on concrete?

The white, fluffy substance is efflorescence and the black spotting on the wall is mold growth. Efflorescence occurs when moisture moves through the concrete and deposits minerals/salts on the surface.

Can efflorescence make you sick?

Efflorescence is typically found on concrete and brick while mold grows on organic materials like wood and drywall. White mold is a living organism (fungus) while efflorescence is simply salt deposits. Efflorescence is not harmful. It won’t make you sick, but white mold will.

Is efflorescence a mold?

A few major differences between efflorescence and mold growth: Mold grows, efflorescence doesn’t. Mold can grow on just about any surface, whereas efflorescence doesn’t spread. Mold is a fungus, whereas efflorescence is moisture that evaporates into salt deposits.