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Efflorescence/ Mottling; Causes and Prevention


If you have experienced it in your home, you might be aware of the term Efflorescence. If this term is new to you, then continue reading. Efflorescence or mottling, as some people call it is the buildup of a crusty white salt, that appears onto the surface of brick and mortar walls, even the surfaces of masonry. Mottling is sign that there is some kind of moisture simmering under the surface.  But, have you wondered why it happens?
Here are some of the common causes of efflorescence.

Why Does Efflorescence Takes Place? 
One of the major causes of efflorescence or mottling is the groundwater that tends to move into the foundation of the homes in capillary action. Quickly, this groundwater makes it into the bricks and results in mottling. If the groundwater contains water soluble salts, the access of this water must be limited from getting to the brickworks. 
Minimizing water absorption is one of the best ways to tackle mottling. The bricks that are used in the walls must have a higher density and a lesser water absorption rate. 
Groundwater containing soluble salts isn’t the only source of efflorescence. Materials such as sand and gravel have the ability to transfer the salts to the brickwork, if they are in contact with water and soil that have salts in them. The aggregate material should be thoroughly washed away, so it does not contribute to efflorescence. 
Clay products are another source of efflorescence or mottling. Products such as blocks and facing bricks have in them soluble salts, which can contribute in the formation of white crystal-like substances on the brickwork. 
To keep the moisture from getting to the bricks, it is very important that they are wrapped and placed at a higher spot, which is away from the ground. Also, the brick must be used with a similar type of mortar. If bricks are used with unconducive mortar, efflorescence is inevitable.  

How to Prevent Efflorescence? 
Here are some easy ways of preventing efflorescence.
  • To prevent water absorption, a hydrophobic sealant must be applied to the surface. Not only will the sealant prevent mottling, but also keep the water from moving throughout the building material.
  • To minimize the risk of salt penetration into the building material, capillary breaks must be installed. 
  • Sprinklers and landscaping must be taken care of, in order to keep the water from getting to the building materials.  
  • Masonry materials should be kept off the ground, and must be covered by a water-proof material. 
To eliminate the issue of efflorescence, one must know the causes of efflorescence mentioned above. If you want to prevent mottling on your property, make sure to follow the aforementioned tips.