What is Efflorescence and why does it happen?
Efflorescence is a natural occurring phenomenon when calcium hydroxide (found in concrete products) reacts with carbon dioxide (found in the atmosphere) to create little calcium carbonate crystals. They can show up as little dots or streaks on concrete substrates like your roof, sidewalk, stairs, etc. Especially when located in a hot, humid, and salty area as this causes efflorescence to thrive.
Efflorescence can begin to show up within the first 6 - 12 months after installation. Although it is not aesthetically pleasing in the short term, it is superficial and not affecting the quality, structural integrity, and function of your new tile. Not to worry, it will eventually fade away. According to the Tile Roofing Institute, ‘Efflorescence is a temporary surface discoloration common to all concrete based building materials… It is difficult to predict how long the effects of efflorescence will last. It depends on the type and amount of deposit as well as the local weather conditions.’