What is that fluffy white stuff in my yard?
By Mark Ortiz, Stone Restoration Specialist
So, we are getting several calls this winter that goes something like this....
"Dear Perfect Granite Solutions, I have all this fluffy white fuzzy stuff on my patio that looks like it's growing and in some places it is crumbling the stone. What is it and should I be worried?"
Our answer: "Yes, be worried, be very very worried!" No! Don't be worried!; and before you lose your mind, let's learn a little about a natural occurrence called, 'Efflorescence'
Is it called, Efflorescence or Effervescence?
The key difference between effervescence and efflorescence is that effervescence is the escape of gases from a solution, whereas efflorescence is the migration of a salt to the surface of a porous material where it tends to form a coating. Although the terms effervescence and efflorescence sound similar, they are not the same. These terms have very different definitions.
But here, we are only talking about Efflorescence...
Efflorescence is a white, powdery substance that often appears on the surface of masonry, concrete, limestone and other building materials. It is caused by the migration of salts from the interior of the material to the surface, where they crystallize and form a visible deposit. Efflorescence is a common problem in many buildings and can be a source of frustration for homeowners, architects, and builders.
What causes it to show up?
A combination of three common circumstances causes efflorescence:
- soluble compounds in the masonry or adjoining materials
- moisture to pick up the compounds and carry them to the surface
- evaporation or hydrostatic pressure that causes the solution to move
If any one of these conditions is eliminated, efflorescence will not occur.
It can start with water from heavy rains, such as we have had in Southern California these last couple months, (which is considered a natural disaster for some of the residences), or maybe a broken sprinkler pipe, or a leaking hose bib. If its interior, it can be noticed around the shower thresholds or shower walls.
The water penetrates the stone or cement, or it goes through the open grout joints, or it's absorbing water from behind the material. Some of you 'poor souls' that live along the beautiful Southern California beaches, have high amounts of ocean salt water. The water absorbs into the stone or cement, reaches the salts in the mortar or cement and dissolves it. At this point there is no issue; but when the moisture evaporates and the air dries it out; then the salt and moisture migrate through the pores and carries the salts to the surface. The moisture evaporates and the salts recrystallize and form on the surface. Wa-la! Efflorescence!
Surface-Efflorescence vs Sub-Efflorescence
Surface efflorescence is visibly not pretty to look at but it's only on the surface and can be rectified fairly easy. Other deposits can occur within, or just below the surface of the material, causing expansion that may disrupt the surface, or cause permanent discoloration, called picture framing.
This condition is sometimes termed crypto florescence, or for us laymen, we call it, sub-efflorescence.
As the salts crystallize just below the surface it can put pressure on the stone and cement, causing the surface to flake off, leaving it rough and pitted. Even though some product manufactures claim you can prevent this with their magic potions, I haven't seen any topical solution, after installation, from preventing this from naturally occuring. But at least we can help maintain it and improve its appearance.
Efflorescence can be easily cleaned off when it appears. Sometimes it only needs to be brushed off and lightly wiped down with a damp mop or towel.
Often it needs a more aggressive cleaning with a light muriatic acid mixture or with vinegar. CAUTION, ACIDS AND VINEGARS ETCH LIMESTONES AND CEMENTS. A test spot should be performed before doing all the areas. If the acid mixture alters the stone too much, then a neutral soap and some aggressive scrubbing may do it.
If the rains continue, then you will need to do it again. It's usually best to professionally clean it about 1 - 2 months after rainy days. If you are having guests over, then clean it off before they visit and wait until drier days before deep cleaning.
Could this have been prevented?
Most of the time the builders and architects have considered moisture and water drainage, but even so, it is normal to see soon after installations. It works with nature and there are certain factors that cause the likelihood of efflorescence. So therefore it cannot always be prevented. Even if you used a man-made tile, the grouts may still show signs of efflorescence.
Give us a call if you would like us to look at your stone, we would be happy to help you out. Or just give you really bad news...but, aren't we pretty used to hearing bad news these days, so it won't be a shocker.
Throughout our homes inside and out, there are unpredictable and sometimes annoying issues. Whether its paint, metal, wood, cement or stone, you need experts in those areas to give you some perspective and solutions.
Sh...Stuff happens, so maybe, this time, let a professional give you some clarity on the situation.
CALL US TODAY IF YOU NEED ANY STONE OR TILE MAINTENANCE and REPAIR.
Stone Repair Expert
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