Efflorescence: How to Address This Common Concrete Flooring Issue

Thursday, February 20, 2020

If you’ve noticed a white “dusting” of particulates on the surface of your concrete flooring, efflorescence has become a problem. 

The good news is, efflorescence can be avoided and corrected with a combination of industrial cleaning techniques and industrial flooring expertise. 

Why are You Seeing Efflorescence?

Efflorescence is the result of a chemical reaction occuring in your concrete flooring.

Water soluble salts combine with moisture as they move through the concrete flooring material to its surface. The result: white dust-like residue (Source: Nitterhouse Masonry Products).

Efflorescence has several causes. The two most common are the concrete mixture itself and the environmental conditions around the concrete flooring. If your concrete was installed with a mixture that had a high water content, was of a low grade, or did not have proper site surface drainage, your floors were at higher risk of efflorescence from the beginning.

Humidity and efflorescence go hand in hand. If there is a lot of moisture in the air due to humidity inside the facility, manufacturing processes that require a high level of moisture, or due to your local weather, you are going to see more efflorescence on your flooring if it’s not properly protected.

How Serious is Your Efflorescence Problem?

Even if you can guess what the cause of your efflorescence might be, you can’t be certain of the extent of the problem, or where there may be vulnerabilities in your flooring, until your floors are tested.

There are two primary efflorescence testing techniques:

Calcium Chloride Test: “The calcium chloride test method is used to determine the moisture vapor emission rate (MVER) from a concrete slab. Calcium chloride testing involves sealing a small dish of calcium chloride on a clean section of concrete under a plastic dome. The salt absorbs moisture in that environment (and presumably coming from the concrete slab) and the weight gain after three days is used to calculate the MVER. (Source: Wagner Meters)” 

This test tells you the condition of the surface of your slab, and the degree to which it has been impacted by efflorescence.

Plastic Sheet Test: The plastic sheet test for concrete moisture is less technical, but can show you how much moisture is escaping to the surface of your floor in real time. Plastic sheets are adhered to the flooring you want to test and left for 48 hours. Once removed after the testing, you’ll be able to see how much moisture has been absorbed as a means of assessing your efflorescence risk.

How is Efflorescence Corrected?

Efflorescence correction measures depend on the condition of your concrete flooring and the degree to which it’s been affected by dusting. Here are solutions that Painters USA can help you implement:

Acid rinse: We use a mild rinse that dissolves the dusting, but does not damage concrete flooring.

Abrasive blasting: Sandblasting removes particulates left by efflorescence completely, so you’re left with restored concrete flooring.

Sealing and Resurfacing: Sealing and resurfacing of concrete floors may be required if damage is significant, or if you’re protecting newly-installed flooring. Depending on your facility, we can recommend concrete polishing services that will seal concrete floors and prevent the escape of vapor and moisture to their surface. 

Painters USA can conduct efflorescence testing, correction, and control in large-scale industrial and commercial spaces. We can ensure your testing conditions are optimal so you get accurate results. Whether your flooring needs to be thoroughly cleaned or requires extensive repairs, we will work with you to get the job done on your timeline so your work site continues to run smoothly.

If you’re looking to correct efflorescence, we’re ready to take on your project. Request an efflorescence control estimate today.