The Ugliest Flower: How much do you know about efflorescence?

By: Staff

4 Min Quiz

Image: refer to hsw

About This Quiz

Efflorescence is a kind of flowering, but it doesn't have roots and it sure doesn't make your yard look good. Test your knowledge of this structural phenomenon with this quiz.

Efflorescence refers to unsightly whitish deposits that can appear on walls or other structural surfaces. What causes it?

Many materials used in construction contain traces and even substantial amounts of salt. Water carries that salt out with it, where it dries into the unsightly patches you may notice discoloring the outsides of buildings.


Efflorescence doesn't occur everywhere. What materials are commonly affected?

Materials like brick, mortar and concrete naturally contain the soluble salt that creates the deposits we know as efflorescence. Wood and linoleum have their own challenges, but efflorescence isn't one of them.


Unless it's pouring rain, you probably don't associate wetness or moisture with the walls of your home. So how does water get inside the material they're made of?

A common culprit for efflorescence is concrete or mortar mix that contains too much water: Even though the material may appear dry, an overly wet mix can leave water inside the structure.


Preventing efflorescence isn't just a matter of being careful when you're mixing concrete; there are environmental factors that can spur its formation as well. What's one example?

Believe it or not, your sprinklers could be causing those ugly blotches on your backyard stucco. Any water that sprays directly on your walls regularly and for extended periods can ooze into the concrete or mortar; excessive groundwater can also seep up into the structure.


What's an easy way to tell if your walls contain excess moisture?

You won't find enough moisture in your walls to fill a cup, but you may notice its presence on a piece of plastic sheeting. Even though it may not look like much, the condensation that excess moisture can cause in this test is a good indication that you may be at risk for efflorescence.


What characterizes primary efflorescence?

Primary efflorescence is caused by factors inherent to the structure, such as the excessively wet cement mix we discussed in question number three. Secondary efflorescence is environmentally based; one example would be the extra-enthusiastic sprinklers in question number four.


Efflorescence is ugly, but it doesn't have to be permanent. What's one effective way to remove it?

Believe it or not, a simple soap-and-water mix can be very effective in removing efflorescence -- just make sure you're ready to scrub. Power washing, sand blasting and chemical cleaning can also be used for more severe cases.


What are some risks to keep in mind when removing efflorescence?

Although the methods mentioned above can be very effective in removing efflorescence, they can also exacerbate the problem if used incorrectly. In general, gentler methods are always better to begin with.


If you're building from scratch, there are a few steps you can take to prevent efflorescence. What is one example?

Sand and gravel play an important structural role in concrete and mortar, but they can also contain excess salt that may cause efflorescence. Ensuring that they are washed thoroughly in salt-free water before mixing can help reduce risk.


Modern-day homeowners aren't the only ones who struggle with efflorescence. Which famous figure also battled the salty blotches?

When he was painting the Sistine Chapel, Michelangelo ran into a problem he wasn't expecting: unwanted discoloration on parts of his work. Let's face it: Efflorescence can be ugly, but at least you're not dealing with it on the surface of a historic masterpiece!


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