Concrete Turns White? Yikes
One of the most common questions a homeowner has is: why does concrete turn white? The answer is surprisingly simple, and it can be quite surprising to find out how common this problem really is. Efflorescence is a natural process that happens on any surface after it is created. Water and cement react to form a paste that binds the aggregate and sand together. Over time, this paste hardens and turns the concrete white.
A good sealer keeps salt minerals in the concrete and prevents it from absorbing moisture. This process also prevents the whitening of the surface. If the concrete is left untreated, the stains will dissolve and turn the surface milky white. This process is called efflorescence, and it is caused by high levels of moisture. During cold weather, the moisture in the concrete becomes trapped under the coating. This impedes the evaporation of the stain, and it also damages the film formation of water-based products.
There are two main causes of efflorescence.
- Excessive moisture, which interferes with the sealing process.
- Overapplied sealers. These materials don’t allow for water to escape, which is why they cause the surface to look white. To remedy this problem, it is best to use a solvent. Then, wash the concrete with a mix of vinegar and water. Then, apply a sealer or another type of coating to the surface and it will be restored to its original shiny state.
The resulting white stain is caused by a buildup of calcium salts on the surface. Efflorescence can result in the white color of the concrete. However, it can be removed by scrubbing the surface with plain water. A thorough cleaning is necessary to remove the efflorescence, but it will likely reappear after a few days in warmer climates. Despite these methods, it is best to leave the concrete untreated until it reaches its final color.
Efflorescence is not a structural issue. It occurs when too much moisture flows through the concrete. After the concrete hardens, the excess water then rises and carries the salts back to the surface. The efflorescent layer is generally visible before the sealing process, while the white residue is visible after. This can be caused by various factors, but it is important to avoid this condition and use a mild acid if you want to get rid of the efflorescence on a concrete floor.
The cause of efflorescence is a chemical reaction between the calcium carbonate in the concrete and the free lime in the air. The moisture in the concrete carries the salts, which result in a white stain on the surface of the concrete. During the curing process, the concrete begins to turn a milky color. It is not safe to walk on it until it has cured properly. This is the reason why the stains on concrete are unattractive.