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While efflorescence in the basement isn’t toxic, it is a sign that a serious problem is brewing in your basement.

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Efflorescence is more of an eyesore than a nuisance to many homeowners. These whitish-grayish crystals tend to appear on the basement walls or floor after a downpour. If you experience this issue, you likely have a basement moisture problem. 

Let’s explore what efflorescence is, what causes it, and how you can prevent it from taking over your basement. 


What Causes Efflorescence? 

Efflorescence is a chalky substance that forms on basement walls and the floor when the masonry loses water through evaporation. What’s left are crystalline salt deposits that appear whitish or grayish. These salts are more of a cosmetic problem than an inherent sign of masonry weakness. 

The water that infiltrates your concrete walls comes from a concrete mix and often carries with it salts to the surface. But that’s not the only source. Water may also come from any number of issues causing water to pool around your foundation walls. 

Such water often carries dissolved salt through capillaries in your mortar, masonry, or concrete. Salty water is less likely to pass through if your basement is built using high-density materials or has fewer channels. 

As the water moves up to the surface, it will start evaporating and leaving behind salt residues on your walls. 

The amount of efflorescence that forms depends on the weather conditions and the levels of humidity. Low humidity means your concrete gives up its moisture fast and this causes salt deposits to crystallize. On the other hand, high humidity reduces the rate of evaporation. Efflorescence is more likely to form in the spring than during a dry summer. 

For efflorescence to form, water, soluble salt, and an entry point must be present. 

Some of the salts that might crystallize include: 

  • Sodium chloride 
  • Sulfates 
  • Silicates 

How to Remove Efflorescence 

Efflorescence usually goes away with time. Also, foot traffic can dislodge the salt residue on your slab or floor. Rain will also wash away the salt deposits. But if you want to remove efflorescence manually, here are your options. 

Simple washing: If the salt deposits are still fresh, you can scrub them with a stiff brush or wash them away with water. Stubborn deposits will require elbow grease. Ensure that you rinse the basement walls properly so dissolved salt won’t crystallize again. 

Power washing: Spraying the basement wall with pressurized water can also help remove surface deposits quickly. Be sure to use the widest-angle tip to dislodge residue and regulate the pressure. Too much of it will open more pores on your masonry and make it prone to efflorescence. 

Chemical Cleaning: Another thing that you can do is dissolve the salt residue with acid cleaners. Begin by soaking the masonry surface with water. What this does is it prevents the cleaning substance from infiltrating your walls and opening more pores. 

We encourage homeowners to try mild removal methods and products before they progress to more aggressive solutions. 

Can You Prevent Efflorescence? 

Yes, it’s possible to stop efflorescence from forming on your basement walls or floor. Engage a basement waterproofing expert from Complete Basement Systems if you suspect moisture is the problem. Here are a couple of things you can do to beat back efflorescence: 

Architectural modifications: Installing a gutter system and adding overhangs and eaves will promote water drainage so water won’t pool around the foundation. 

Positive grading: Your yard should have a gentle slope that allows water to flow away and not towards your home. 

Moving flowerbeds: Garden plants that need regular watering can leave your basement open to water damage. Move them away from your home perimeter and ensure the sprinkler doesn’t splash water on your walls. 

Surface sealants: Covering your foundation walls with a hydrophobic sealant can stop moisture from rain or melting snow from infiltrating the basement. These are usually temporary solutions, however. 

Capillary break: Applying a vapor barrier to your crawl space or basement walls will lock outside moisture and groundwater from your home. 

True, efflorescence is a cosmetic issue. It won’t cause cracks or make you ill. However, it’s an indication that your basement walls or floor are porous. Postpone the problem and you could be staring at water damage and expensive repairs some months down the road. If you suspect that efflorescence is forming on your basement walls or floor, contact our experts for a free waterproofing inspection and quote. We’ll unearth the source of the problem and apply the right fix to help prevent salts from crystallizing in your basement.

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