A few years ago, a general contractor took on a project for a friend of his who wanted to open up their living space by removing an interior wall. As the general contractor cut into what he thought was a nonessential wall, he heard the sickening sound of splintering wood echo through the entire house, as the ceiling began to sag, and cracks began to develop in the drywall. He had cut through a load bearing beam. You can only imagine the ensuing battles he had to endure following his mishap.
General construction knowledge indicates that when removing a wall, there are a few critical items that need to be assessed prior to breaking out the Sawzall. First, check to make sure the wall is not load-bearing, and second, check for any electrical, plumbing, gas, and HVAC that may be hidden in the wall. This costly catastrophe could have been avoided had the general contractor conducted a thorough evaluation before cutting into that wall.
How is installing a floor at a jobsite that you havenāt thoroughly evaluated any different?
TIME IS MONEY
Flooring contractors generally want to do things correctly to avoid potential issues and to ensure the conditions meet or exceed manufacturer requirements.
Advancements in many of the newer products that have been introduced to the wood flooring industry are vastly improving the way we conduct business. Technology has brought us tools that simplify our processes, systems that shorten the amount of time necessary on the jobsite, and products that have increased the long-term performance of the floor.
One of the product advancements that has added tremendous value to the jobsite is the multi-functional flooring adhesives category. This category of adhesives saves time by eliminating multiple steps in the process, ultimately reducing overall costs. Each product has multiple functions, which may include crack bridging, moisture control, sound control, and mold/mildew resistance. These products are often marketed as two-in-ones, three-in-ones, four-in-ones, or even as being capable of āunlimited moisture protection,ā while ensuring the contractor that there is āno need to moisture testā the slab. These new products and processes provide faster and more efficient alternatives to what we are accustomed to. They have been developed on the premise that āTime is Money.ā
With these advancements in technology comes a responsibility, and a learning curve by the flooring professional. While the promises of āno need to moisture testā are tempting to contractors looking for simplicity and assurance, they also can expose the installer to a level of risk that essentially shifts liability directly back to them. Without the data provided through moisture testing, the contractor is not likely to have a leg to stand on in a litigious situation.
The only way to learn about the moisture condition of the slab is through moisture testing. Moisture testing is a crucial step in ensuring the success of any wood floor installation. To ābecome awareā of what the moisture condition of the slab is, is to āunderstandā how to properly prepare the slab for installation, and to decide what systems to use. The issue is that learning about the moisture condition of a concrete slab takes time, money, and energy. Just as it would have taken time, money, and energy to check that the wall was not load-bearing before cutting into it.
THE CHALLENGES OF MOISTURE TESTING CONCRETE
To assess the moisture condition of the slab, flooring contractors rely on various testing methods, including calcium chloride tests, relative humidity in-situ tests, and electrical moisture meter tests.
The calcium chloride (CaCl) test (ASTM F1869) is an invasive test that requires adequate preparation of the test area, grinded to a CSP 1-2, 24 hours prior to placing the test, then setting the test and coming back within 60 to 72 hours to measure the results.
The in-situ relative humidity (RH) test (ASTM F2170) is an invasive test that requires identifying slab thickness, drilling holes in the slab to a designated depth based on that slab thickness, then placing the sleeves in the holes and letting them sit for 24 hours before taking readings.
The electrical moisture meter test (ASTM F2659) is quick and easy (just like testing wood products), but has not yet been accepted through ASTM as providing quantifiable data to justify whether the moisture condition of the slab is acceptable or unacceptable for installation purposes.
Each of these test methods are specific and unique in what they are testing, at the location they tested, and at the precise time of the test. Whether itās the accuracy of the data provided by each test, or the time necessary to acquire that data, each has its strengths, and each has its limitations. As a friend taught me several years ago, the most accurate perspective you can capture about the moisture condition of a slab includes conducting all of these tests, along with assessing the ambient conditions in the space, then assessing the results from a broader perspective of the overall moisture condition of that slab.
Flooring contractors always are looking for more streamlined, accurate, and cost-effective methods to assess the jobsite before installing a wood floor. Manufacturers have listened, and have answered the call with āunlimited moisture protectionā products. Because of these advancements, the temptation to skip the moisture testing step has become more common. For many flooring professionals, the reward outweighs the risk. Itās a business decision.
When a project is affected by moisture, no one can account for all the variables that influence moisture dynamics nor how the floor/subfloor system will react. The shift toward āunlimited moisture control systemsā marks a significant evolution in product value and performance. These products change how we manage the moisture-related challenges our floors are exposed to at the jobsite.
As the professional flooring contractor, it is 100 percent your responsibility to check the jobsite conditions, at the time of installation, to gain a clear perspective of the state of the jobsite you will be installing flooring in. Without an analysis of the jobsite and the slab prior to installation of your floor, you are no different from the contractor who cut into that wall without investigating whether it was load-bearing.
To protect yourself, remain diligent about conducting moisture tests. You also should take advantage of these ever-evolving moisture protection products, just donāt do so without doing your due diligence in assessing the moisture conditions of the slab. In the end, installation of flooring constitutes acceptance of the site conditions at the time of installation.
Brett Miller is the vice president of technical standards, training, and certification for the National Wood Flooring Association in St. Louis. He can be reached at brett.miller@nwfa.org.
Excellent Article. In installation contractors failure to test for moisture in the slab will most often lead to flooring failure. The installer should also test the slab for pH conditions that can and will affect adhesives and coatings. Most conventional adhesives will not perform effectively when the concrete pH exists out side the range of 7.0 to 10.0. The installer should also test the slab for porosity to determine if a slab is a porous or non porous Slab. Proper Selection of adhesive will often be dependent upon the porosity conditions of the concrete slab. Remember This: You can never do to much testing and evaluation of a substrate, but too little testing of the future installation site can and probably will lead to costly flooring replacement and/or repairs, and in the worst case scenario damaging litigation that will generally cost a lot more than the original bid on the project.
Great point Ralph! And thank you.