When Leapfrog Becomes Fatal
Concrete moisture measurement helps to avoid mildew, mold, gaps, and bumps in concrete floors. Successful builders test moisture content to ensure equilibration before proceeding to install floor coverings over subfloors. Excess moisture in concrete causes floor covering failure and perpetual concrete moisture problems.
In short, installers have plenty of reason to incorporate precise moisture content measurement into their work processes.
It reminds me of Tuamauna Manglou, a 389-pound defensive lineman who was known for severely head-butting opponents. “Tua,” I said slowly, “you’ve helped us to 10-and-3 by injuring the best opposition players. It’s helping us win, but we’re losing 212 yards per game to penalties.”
“Yuh,” he replied. “Uh know. Something needs to be changed. I try new attitude next game.”
Manglou delivered. We watched him leapfrog the opposing lineman, then sack their quarterback with Tuamauna’s signature head-butt. We only won because the other team had no quarterbacks left. The league subsequently suspended Tuamauna Manglou for the remainder of the season.
Concrete flooring installers have their own version of leapfrog and, curiously, it creates similar consequences.
To explain, the American Society for Testing and Materials (ASTM) provides concrete moisture content standards for the use of in situ probes:
ASTM F2170: Moisture permeating from concrete floor slabs affects the performance of flooring systems such as resilient and textile floor coverings and coatings. Manufacturers of such systems generally require moisture testing to be performed before installation on concrete. Internal relative humidity (RH) testing is one such method.
The idea is to pre-empt concrete moisture problems by measuring any variations throughout a concrete slab.
Leapfrog is played a little differently in the concrete installation game. Installers place RH probes in concrete. In order to measure RH, some probes need to equilibrate (reach accurate measurement capability) over several hours. Installers trying to assess RH often quickly leapfrog the probes from hole to hole in the slab, each time neglecting to allow sufficient probe equilibration time. Leapfrog grossly underestimates the slab’s real RH. Installers see pleasing data and move on, unaware that the data’s inaccuracy only increases the likelihood and the costly nature of a moisture-related floor covering failure.
Tuamauna Manglou put the sharpest part of his helmet right into the chin of the quarterback, unaware (at least at that moment) that he would be suspended for doing so. He sacked the quarterback; he sacked the team, too.
Wagner Meters’ Rapid RH® concrete moisture meter contains Smart Sensors which solve a contractor’s tendency to leapfrog to floor failure. Each test site has a Smart Sensor. Each Smart Sensor remains in the slab to accurately measure RH content without repeat equilibration time. The Rapid RH® concrete RH in-situ test assures a winning decision on floor installation without penalty.
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