Efflorescence is driven by hydrostatic pressure – the pressure exerted by moisture as it moves through concrete to the lowest point. As the moisture enters and moves through the wall or floor, it dissolves mineral salts present in the cement component of the concrete.
But if you wall has a high salt content, the efflorescence could develop again and again. The first thing to do is to take steps to keep water off of the wall as much as possible and see what happens. Consider a penetrating sealant that is specifically made to prevent efflorescence.
It is common for people to confuse mold with efflorescence. Efflorescence itself isn't dangerous or harmful. It can lead to potential moisture problems that can cause structural damage to building materials.
CAUSES OF EFFLORESCENCE
Simply stated, efflorescence occurs when water containing dissolved salts is brought to the surface of masonry, the water evaporates and the salts are left on the surface.
Clear water repellents, silicone and acrylic coatings also may help you remove efflorescence as well. The coating will absorb water across a masonry surface and prevent efflorescence from recurring. Plus, the combination of warm water and white wine vinegar has been shown to eliminate efflorescence.
In many cases, efflorescence will disappear on its own over time (usually after the first year of a paver or retaining wall installation).
By sealing too soon, you'll run the risk of trapping migrating salts beneath the coating of sealer. And the only way to remove the haziness at that point is to strip the sealer and then clean the efflorescence. (Do not risk having to endure this nightmare … you'll surely regret it!)
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.
Efflorescence alone does not pose a major problem, but it can be an indication of moisture intrusion, which may compromise the structural material. Building materials, such as concrete, wood, brick and stone, are porous materials. Porous materials can absorb or wick water by a process called capillary action.
RadonSeal Efflorescence Cleaner can be safely used on poured concrete, concrete blocks, bricks, stucco, pavers, and artificial stones. The cleaner chemically breaks down and removes efflorescence, lime deposits, metal salt stains, and rust deposits.
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.
By sealing with a penetrating concrete sealer, concrete is hardened up to 45% and efflorescence is eliminated. Since humidity can affect efflorescence, it has been shown that it can be a seasonal problem with efflorescence being most common during rainy seasons.
These deposits can appear within days of construction being completed or sometimes even only years later depending on weather conditions and quality of construction. Three conditions are required for efflorescence to occur. There must be water soluble salts present somewhere in the substrate or mortar.
A solution of baking soda (sodium bicarbonate) and water (Approx. 1 lb. Of baking soda per 5-gallons of water) can be used to neutralize the stain. The solution should be applied until it stops fizzing.
A mild solution of muriatic acid in water is a conventional chemical cleaner used for clearing efflorescence.
Regular white vinegar with 5% acidity works fine. With a sponge, apply vinegar to the area with efflorescence and clean it a circular motion. Leave the solution on the area for 10 minutes before rinsing the area thoroughly with water. Vinegar works best on surfaces like stucco, but can also work on concrete and bricks.
Efflorescence of this type can be removed with a dilute acid solution (such as one part hydrochloric acid in 9 to 19 parts water or one part phosphoric acid in 9 parts water). After treatment the area should be washed with clean water to remove all acid.
Efflorescence, it is not a structural, but rather an aesthetic building concern. Efflorescence and water-proofing failure are common problems in the construction industry. Concrete materials such as tile beds, adhesives, grout, concrete and render are all ordinarily porous.
The easiest way to remove efflorescence is to wash the substrate and scrub the area to see if the stains disappear. Only clear water should be used to avoid worsening the situation. The sooner the attempt to remove the stains, the better, as time will be against you.
If you own a pressure washer, there's no easier way to clean any salt deposits off of your bricks or concrete. Under a high-pressure stream of water, all of that efflorescence will quickly be dissolved and eliminated. However, you need to make sure that all of the water you use is completely dried off.
To start the maintenance process, use a solution of regular dish soap and water along with a stiff plastic scrub brush. Avoid using a wire brush, as it can dislodge wires and create rust marks on the surface.
Concrete efflorescence is a serious problem. These white spots are not harmless and are a sign that it's time to take care of your concrete. Rest assured, every problem has a solution. Before any renovations that could damage your garage floor, check out our handy little guide on efflorescence.
Coating the walls is the best way to prevent efflorescence on brick and walls. Investing in a brick sealer will help keep water away from entering the wall, ultimately preventing the risk of efflorescence. Our masonry crème is an excellent waterproof paint to consider for efflorescence prevention on painted walls.
Efflorescence appears as a white deposit of mineral salts on face of concrete walls and/or floors. Efflorescence usually appears in underground car park areas and other subfloor areas. Efflorescence is driven by hydrostatic pressure – the pressure exerted by moisture as it moves through concrete to the lowest point.