Efflorescence: Definition, Causes, Removal, and Prevention

Efflorescence is a problem that commonly exists in masonry and concrete block foundations. If you look closely at your basement wall, you might see a white fuzzy build up. This is efflorescence. You don’t need to worry about this being dangerous; it’s just salt seeping out from soil, clay, or Portland cement. More than anything else, it’s an indication that you have a problem with moisture and if efflorescence isn’t given proper treatment it can result in deterioration.

This build-up on the surface is caused by water infiltrating the concrete wall or block and dissolving the minerals. The water will eventually evaporate from the surface, leaving the mineral deposits behind in the form of efflorescence crystals that continue to grow. Although this build-up can appear unsightly, if the crystals keep growing within the surface of the block or wall, it can lead to spalling, which happens when the surface begins to peel or flake off. The salt pushing from the inside out causes this and, eventually, it can result in the unit crumbling and falling apart.

If you remove the efflorescence only to have it reappear, this is a signal that moisture is seeping in and forcing the salts out.

There are three conditions that must exist in order for efflorescence to occur:

  1. Water-soluble salts must exist somewhere in the structure.
  2. Enough moisture must be seeping into the wall to begin dissolving the salts.
  3. A path must exist for the soluble salts to make their way through to the surface so the moisture can begin evaporating, causing the salts to leave crystallized deposits, which create efflorescence.

Efflorescence Can be Prevented

The most effective way to prevent efflorescence is to keep water from seeping into the wall. If you notice efflorescence crystals, there is probably a leak somewhere allowing water from the outside get in. Once you locate the source of the water leak and get it plugged, you can then use an efflorescence remover to clean the walls.

While water seepage from the inside can be resolved by diverting the water, the problem of efflorescence and other mineral build-ups related to moisture may not be totally solved. No matter what you do on the inside, water may still be seeping through the wall from outside sources.

Removing Efflorescence

First, the wall must be thoroughly rinsed with clean water before starting application of muriatic acid solutions. After cleaning the surface, make sure it is completely dry before proceeding. A mild solution of muriatic acid has been effectively used for years to remove efflorescence. The solution is usually made with two parts water and one part muriatic acid for a 10% solution. (For block surfaces, use 5:1 Water to Muriatic Acid for a 5% solution) Several individual applications of a mild solution are far better than one strong dose. Once the efflorescence is gone, the wall should again be flushed with clean water. Mix 1 cup of baking soda per gallon of water to neutralize the remaining acid during this step.

Keep in mind, just because you’ve cleaned the build-up from your masonry wall doesn’t mean you’ve solved the problem. Efflorescence will return unless you find the source of the water seepage and fix it.

Efflorescence is a condition that can be controlled and should not exist in this day and age. Resolve the conditions needed for efflorescence to occur with the correct materials, attention to detail, and good quality construction.

The SANI-TRED Solution

The SANI-TRED® system has been trusted by over 100,000 do-it-yourself-ers and contractors to permanently waterproof basements and more. SANI-TRED® permanently bonds with concrete forming a shield against water permanently. Protect your basement and stop efflorescence with SANI-TRED’s efflorescence blocker.

To find out more about how we can help you to remove efflorescence from concrete block walls, call our experts at 1-866-784-3308 or visit SANI-TRED today.

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