Efflorescence
What is Efflorescence?? What does it look like??
Efflorescence has been in existence since the beginning of time. Its existence is noticeable throughout various structures, statues, monuments and building projects worldwide. It is not limited to any specific geographic area.
Efflorescence is a white crystalline deposit that is composed of salts, lime and/or other minerals. These deposits may become visible on many types of building surfaces such as concrete, stucco, grout, masonry, brick, natural stone, clay, ceramic tile and even wood. These salts and minerals are water-soluble and generally come from the ground or where cementitious or alkali substances exist. These salts and minerals travel to the surface, using moisture as their carrier, and when the moisture evaporates what is left behind are salts and minerals on the surface.
The process by which it occurs is the free calcium, usually from a cement based product, is dissolved in water in the form of calcium bicarbonate. On being brought to the surface during the drying process, it reacts with carbon dioxide from the atmosphere to form calcium carbonate.
This is the same process that forms stalactites and stalagmites in limestone caves.
Calcium Carbonate, being an insoluble salt, will not just wash off but needs special cleaning methods and procedures. The problem is especially known to to occur on not only on external but also on internal surfaces that are continually subjected to wetting and drying which results in a continual depositing of salts on the surface.
The way to control its formation is to minimize the sources of free calcium that feed it.
The two main products used in tiling systems are cement based adhesives and coloured grouts that contribute to a major source of free calcium.
What can be done?
Calcification can be minimized or eliminated by applying a good, breathable penetrating water repellent to your surface. Actually many good water repellents can help efflorescence from occurring when the original source of moisture is coming from the exterior elements or from below.