What Causes Efflorescence? Best Tips for Prevention and Removal

Have you ever seen a white powdery or fluffy substance on the surface of concrete, brick, or cement block? That’s efflorescence and it’s actually a common occurrence on the surface of masonry structures.

So what causes efflorescence? And is there anything you can do to prevent or remove it?

In this 3-minute read, you’ll get everything you need to know. Let’s get started.

What Is Efflorescence Anyway?

Efflorescence is a crystalline deposit left on the surface of concrete, mortar, cement block, and brick. It forms when moisture combines with soluble salts in the masonry. When that mixture reaches the surface and evaporates, it leaves a white, grey, or sometimes green salt deposit.

So what actually causes this to happen?

What Causes Efflorescence on Masonry?

Here are four common causes of efflorescence.

Cause #1: Excess Moisture and Salt in Porous Masonry
For efflorescence to form, three things have to happen.
  • Moisture needs to get in the masonry
  • Enough water soluble salts (like calcium sulfate, calcium hydroxide, calcium carbonate, sodium carbonate, and potassium carbonate) need to be present in the masonry
  • The masonry needs to be porous enough to let the moisture in and then back out to the surface
So what can cause these three factors to combine and create efflorescence? Check out the next three causes.
Cause #2: Incorrect Building Methods

Improper construction methods are one of the leading causes of efflorescence. A poorly constructed building can quickly let moisture go places where it shouldn’t. Then, that excess moisture combines with the salt compounds, comes to the surface to evaporate, and leaves behind efflorescence.

Cause #3: Deteriorating Structures

As buildings age, moisture can start to penetrate the structure in critical areas. This is especially true if you live in an area with extreme temperatures. Frequent freeze/thaw cycles and heavy rain can slowly cause problems, especially with softer materials like grout and mortar joints. Even damaged chimney flues can allow condensation to seep into the chimney brick.

Cause #4: Low-Quality Materials

High-quality materials will be less likely to allow moisture penetration. Concrete that has been properly vibrated and tamped will have fewer capillaries that could allow water to penetrate it. Denser blocks will prevent water penetration. And most high-quality bricks have additional substances added to neutralize some of the salts.

*That’s why it’s so important to hire a professional masonry contractor for your next project. Get it done right the first time so you’ll be less likely to deal with problems later. If you’re in the Garland, Dallas Texas area, give us a call at A&X Masonry. Get your FREE quote today!

Tips for Preventing Efflorescence

1: Follow proper building methods to limit moisture prevention

This is extremely important for more than just preventing efflorescence. It will help protect the rest of your home as well.

Professional contractors or homeowners who are DIYing a masonry project should :
  • Install vapor barriers. One place to do this is under a concrete slab foundation.
  • Add flashing around brick or stone chimneys
  • Slope the ground so it directs water away from your concrete or block foundation
  • Completely fill all mortar joints
  • Seal concrete and block when necessary
  • Use high-quality concrete with a larger percentage of fly ash. This creates stronger concrete and even works to neutralize some of the salts that could cause efflorescence. *Check out this article from World of Concrete to see how that works.
2: Go With High-Quality Materials

Salts are present in most materials like concrete, grout, mortar, portland cement, sand, and bricks. But better materials often have fewer active salts that can cause efflorescence. Go with washed sand. Buy high-quality bricks and blocks that are denser. Choose low-alkali mortar and higher-strength concrete.

3: Regular Maintenance to Prevent Efflorescence
Proactive maintenance will help you spot problems that could cause efflorescence.
  • Check the masonry walls around your house for signs of moisture
  • Inspect the mortar joints (especially exterior ones) for cracks and deteriorating mortar
  • Make sure to seal and repair any leaks as soon as possible
  • Get your chimney inspected on a yearly basis
Most handy homeowners can take care of small repairs. But for larger repairs, it’s best to call a professional contractor. If you’re in the Garland, Dallas Texas area, contact A&X Masonry for your FREE quote.

How to Treat and Remove Efflorescence on Concrete, Brick, and Other Masonry

So if you’ve already started to notice some concrete efflorescence, what can you do to remove it? Here are three things.

#1: Clean It With a Brush and Water

Before getting out the heavy duty concrete cleaners, start with some good old clean water, a scrub brush, and some elbow grease. If needed, you can even add a little baking soda to your brush to improve its scrubbing power. Scrub the surface and then rinse with clean water.

PRO TIP! – A pressure washer can also help remove efflorescence. Just be careful using it on old or damaged masonry since it can actually damage it.

If the surfaces still have stains, move on to step two.

#2: DIY Efflorescence Cleaner Mix a mild acid solution of one part white cleaning vinegar to two parts water. Spray, sponge, or brush it onto the surface. Scrub it with your brush. Then rinse with clean water. Important! Any time you work with acid, even vinegar, don’t forget to use proper PPE like safety glasses or goggles. If you’re still seeing efflorescence stains on the surface, move on to step three.

#3: Store-Bought Efflorescence Cleaner

A ready-made chemical cleaner like Foundation Armor Concentrated Concrete and Brick Efflorescence Remover and Cleaner is one of the easiest ways of removing efflorescence from concrete. Just follow the instructions on the cleaner you buy to dilute and apply it.

Summary

Efflorescence on concrete may be a sign of more serious issues. So if you start to notice it on your wall or floor, it’s best to get it checked out right away. Do that and you’ll minimize the possibility of more serious structural damage to your building.

Need a professional to come take a look? Live in the Garland, Dallas Texas area?

Give us a call today at A&X Masonry. We’d love to come out, help diagnose the problem, and then work with you to find the best possible solution.

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