Moisture in concrete slabs, whatever the source, is the Achilles heel of the flooring installation industry because of the impact it can have on much of today’s flooring, which is less forgiving with respect to moisture than products of the past. In addition, many of today’s adhesives are more sensitive to moisture than their predecessors. 

Flooring installed over a concrete slab that contains a high moisture vapor emission rate is likely to bubble, discolor, de-bond or have moisture coming through the seams or joints of the flooring. This almost universally results in costly remediation, dissatisfied end users and a black eye for the installation contractor and the flooring industry as a whole. 

High Stakes Game

The stakes are high for flooring installation contractors, project managers, general contractors, building owners and others because failed flooring installations caused by moisture in slabs are extremely costly to remediate. The North American Commercial Property Owners Association pegs the cost of repairing failed flooring installations caused by moisture problems in the U.S. at approximately $800 million annually. 

With so much at stake, project managers, general contractors, building owners and others can take the following three steps to ensure the best outcome when faced with moisture in concrete slabs. 

Step 1: Understand the Sources of Moisture

Moisture in concrete slabs can come from a variety of sources. Those involved in commercial construction projects who understand the basic sources of moisture are in the best position to head off costly moisture problems. 

For example, some new slabs are poured under roof and others are poured before the walls and roof are put into place. In the latter case, there is a high probability that the slab will have been subjected to the direct sun, rain and wide temperature swings during the curing process. All of these conditions will affect moisture levels in the slab. 

Existing slabs may have been damaged during construction, allowing moisture to settle in them. In other cases, moisture barriers may have been compromised over time – or perhaps never used at all – allowing ground water to migrate up through slabs. When this is the case, moisture levels can rise or fall, as moisture evaporates from the slab and is then re-introduced, depending on changing climatic conditions. 

Step 2: Understand the Basics of Moisture Testing and the Latest Moisture-Testing Technologies

Most flooring and adhesive manufacturers require stringent pre-installation moisture testing not only on the surface, but also 40 percent down into the depth of the concrete slab. For example, with a six-inch slab, the moisture testing probes should be set at a depth of 2.5 inches. Tolerance for moisture differs from one flooring product to another, so documenting test results and sharing them with manufacturers is essential. 

New moisture testing technology was recently introduced that consolidates many concrete moisture testing tasks and simplifies the moisture testing process. The same system is also capable of storing more than 500 time-stamped measurements, so it is possible to recover historical data years after the moisture testing took place. That can be valuable information for those involved in commercial construction projects in today’s litigious society. 

In addition, a number of new technologies have been introduced to further enhance the state-of-the art of moisture testing. Among the most noteworthy are relative humidity probes manufactured by Wagner Meters that significantly decrease the time it takes to conduct moisture testing, an exceedingly important feature in today’s era of fast-track construction. 

Step 3: Hire the Best Moisture Remediation Contractor

There are two things that separate the best moisture remediators from the rest of the pack. First, they have been factory trained or certified by organizations such as the International Concrete Repair Institute to properly deal with moisture issues in concrete slabs. This training enables them to properly recognize and address moisture issues in both new and old slabs and can go a long way to avoiding costly immediate-and long-term problems. 

Second, the best moisture remediation contractors can demonstrate that they have kept up with the latest moisture mitigation products through training and continuing education. Training and continuing education programs are offered to most interested parties by product manufacturers, leading flooring distributors and others. 

Experienced moisture remediators also have access to select distributors of flooring and flooring installation products, who can add value to the conversation in a number of ways. They are well versed in how best to address moisture problems, and they have an in-depth understanding of the range of products on the market that can most efficiently and effectively deal with moisture issues. 

End User is Beneficiary

Proper moisture remediation in concrete slabs is often not only a necessary first step in a flooring installation, but it is the foundation on which the success of the entire installation rests. The ultimate beneficiary of a job well done is not the project manager, general contractor, building owner or even the flooring manufacturer. The ultimate beneficiary is the end user, whose repeat business should be the goal of everyone involved in the flooring industry.