Usually this white or off-white discoloration to concrete and masonry forms when soluble salts and other water dispersible materials come to the surface through capillary voids as a result of temperature changes, moist migration, condensation, rain, dew, and/or too much water in the mix.
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.
In many cases, efflorescence will disappear on its own over time (usually after the first year of a paver or retaining wall installation). Efflorescence can also be removed with special cleaners like the Gator Efflorescence Cleaner. On average, you should wait about 60 days before applying an efflorescence cleaner.
In many cases, this is because of efflorescence. Efflorescence is that white powdery substance on the surface of your concrete that can appear over time. It can occur on anything containing portland cement and is commonly seen on concrete floors.
Efflorescence itself isn't dangerous or harmful. It can lead to potential moisture problems that can cause structural damage to building materials. So it is important to take action when you notice efflorescence in your basement, on your paving stones, or on other structures.
While efflorescence on bricks, white spots on concrete, and chalky mineral deposits are unsightly, efflorescence is naturally occurring and should not be feared as it poses no adverse health risk, generally speaking.
In short, efflorescence is rarely indicative of serious structural damage to your foundation. It poses no serious threat to the overall health of your foundation; however, the excess moisture that is causing the efflorescence breakout may be problematic.
Efflorescence and alkali salts can be removed by dry brushing with a stiff bristled brush followed by wet sponging the surface with a mild 5% solution of white vinegar (acetic acid) in water. The whole area should then be wiped down with a damp cloth and allowed to dry thoroughly.
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.
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.
Efflorescence must be removed before applying a penetrating sealer.
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 cement material.
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 is the white chalky powder that you might find on the surface of a concrete or brick wall. It can be a cosmetic issue, or it can be an indication of moisture intrusion that could lead to major structural and indoor air quality issues.
Combine 1/4 cup of liquid bleach with 1 gallon of hot water in a large bucket. To avoid damaging your lawn or walkways, always dilute your bleach and control your runoff when rinsing. Soak your brush in the solution and scrub the entire area until it's fully saturated.
If your wall started out with only a small amount of water-soluble salts within it, the efflorescence might stay away on its own after one cleaning, or only lightly return. But if you wall has a high salt content, the efflorescence could develop again and again.
Efflorescence occurs when water soluble salts travel to the concrete surface. The mineral salts might be a result of the cement hydration reaction or can come from many other sources like sulphate rich sand. Porous concretes, masonry and mortars will be more susceptible to the migration of salts to the surface.
RadonSeal Efflorescence Cleaner is extremely effective for the removal of efflorescence, dissolved salts, lime, and alkalis. However, lime (calcium hydroxide) in the efflorescence gradually reacts with carbon dioxide in the air (carbonation), forming calcium carbonate (CaCO3).
Overall, efflorescence is a common phenomenon that is individual with each and every case. It is not harmful but can look unappealing and unattractive. However, over time, efflorescence will gradually disappear.
Judging from the feedback received at the Pavingexpert website, most cases of efflorescence become noticeable 3-6 weeks after laying is completed and then last for 3-6 months before gradually disappearing over a period of 3-6 months.
If you live in an area of frequent rain and sunny days, efflorescence and its passing may occur quickly. The process may take much longer in drier climates. Typically, efflorescence will stop developing in approx- imately 18 to 24 months.
Differences Between Efflorescence & Mold
Mold can grow on just about any surface, whereas efflorescence doesn't spread and forms on cement or brick. Mold is a fungus, efflorescence is moisture that evaporates into salt deposits. Efflorescence will turn into a powder when touched, while mold will not.
Efflorescence is the formation of insoluble salts that appear as white coloured staining on tiles, concrete, brickwork and stone and is generally considered as a building defect.
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.