The new floor is in, and the diplomats are arriving for the show. What’s that smell? Why is glue seeping from the cracks between floor tiles!? Welcome to adhesive breakdown in flooring, a catastrophic product of moisture content and high pH.
Moisture vapor naturally evaporates from the surfaces of all concrete floors. If installers used a calcium chloride test to measure a moisture vapor emissions rate (MVER), they learn that the floor contains 2.76 pounds of water crystals per thousand square feet of floor. Generally, moisture vapor experts do not install floor covering materials with an MVER rate exceeding three-to-five pounds. In this scenario, the contractor likely proceeded, because the MVER read less than “3.”
If the floor suffered adhesive breakdown and only surface testing was conducted, the internal RH would have potentially showed higher levels of moisture. In a high RH environment, moisture vapor can contain high pH levels in concrete. If high enough, high pH causes adhesive breakdown due to high RH. The floor fails because its covering does not adhere to the subfloor. Application fluids leak instead of sticking. If so, the high pH of moisture vapor is the culprit.
The calcium chloride test, known as MVER, was developed in the 1950s. It consists of sealing a dish with a known weight of anhydrous calcium chloride crystals to a concrete surface for 72 hours. Builders then calculate the MVER (moisture vapor emission rate) by calculating how much moisture the crystals absorbed. Floor materials manufacturers generally recommend that installers confirm a “3″ or “5″ emissions reading before proceeding.
Industrial evolution has revealed cracks in MVER’s methodology. Put simply, MVER does not account for high pH or high RH in moisture vapor levels. Calcium chloride cannot help contractors avoid adhesive breakdown, because MVER does not indicate relative humidity deep in the concrete.
Relative Humidity Tests
Contractors have a new ally: relative humidity testing. Moisture content measurement detects high RH levels before contractors mistakenly apply floor coverings to subfloors that are outside the limits set by the adhesive or flooring manufacturer. Wagner Meters provides cost-effective moisture content tests based on relative humidity. If high RH causes high pH, moisture metrics will put a stop to floor covering installation before it ruins the project. Hand-held digital meters from Wagner Meters arm contractors and consumers with the means of identifying potential high RH and the need for further testing before it produces adhesive breakdown.
Question: “How could you blow something as simple as moisture content measurement?”
Answer: You wouldn’t blow it with a Wagner Meter.