Why is my concrete turning white? Efflorescence is a white salty residue caused when too much moisture is moving through the concrete. As the concrete dries and its moisture rises upwards through the slab, it brings salts within the concrete to the surface as well.
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.
In fact, it's a normal and natural occurrence that can happen in any cement-based product. In many cases, efflorescence will disappear on its own over time (usually after the first year of a paver or retaining wall installation).
When soluble salts, moisture, and migrating channels combine, you can get efflorescence. As moisture rises to the surface of the concrete, it carries with it the calcium salts from within the concrete. These react with CO2 at the surface, forming that white powdery dust.
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.
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.
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.
Unless something else is done, the efflorescence will be back soon. In order to prevent it, you'll need to: Eliminate soluble salts for your concrete or masonry, and/or. Prevent water from transporting soluble mineral salts to the surface.
Seeing the crystals on the wall will typically mean that there is a leak somewhere that is letting water inside the home. Once the leak is stopped, the efflorescence can be effectively treated and removed from the wall's surface.
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.
Efflorescence on pavers will eventually stop on its own after the salts in the pavers have dissipated. On the other hand, recurring efflorescence may indicate an ongoing problem of water intrusion that needs to be addressed before it causes permanent damage to the structure.
The acidity in the vinegar helps remove the efflorescence and calcium deposits by breaking down mineral crystals. After cleaning the surface, let dry for 48-72 hours (moisture content below 25%).
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.
This form of efflorescence generally lasts around two to three years and fades naturally as the salt supply decreases. Salts are carried to the surface of concrete or brickwork by hydrostatic pressure or osmosis/evaporation, and deposited when the water evaporates, resulting in this type of efflorescence.
Efflorescence is removed by natural weathering processes - as rainwater is slightly acidic, it gradually dissolves and washes away the deposits. The process may also be assisted by warm dry weather when the deposit is blown away.
The reason high humidity can cause efflorescence, is because high humidity leads to condensation forming on the masonry surfaces. Condensation causes beads of moisture to form on the cool surfaces and is absorbed into the porous cement. Remedy For Excessive Humidity: Buy a good dehumidifier for your basement.
Good building practices are essential. Remember, you're trying to avoid the three essentials of efflorescence: keeping salts out of the masonry, keeping water out of the slab and avoiding porosity in your stone work. Use high quality concrete that contains minimal water.
The truth is that a dehumidifier does nothing to counter or reverse the effects of efflorescence on your crawl space walls.
A: Yes. We recommend using a 50/50 solution (equal parts of CLR Calcium, Lime and Rust Remover and warm water.) Apply solution to the affected stained areas of the windows using a damp cloth or sponge.
Zido is not only effective in removing efflorescence from brick, but also from mortar, concrete and grout. It makes the surface look new 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.
Pressure washing can work to remove white efflorescence once the surface has thoroughly dried. The surface must be thoroughly rinsed to ensure that no residue remains. We also use a safe detergent to ensure a thorough clean.