Why flooring installers need quantitative moisture readings
Another industry that benefits from quantitative moisture measurement is the flooring industry. Wood flooring installers often require precise measurements of the moisture content of the wood they are using as well as relative humidity (RH) for an accurate assessment of installation site conditions.
Why is it so important to make quantitative moisture measurements? The main reason is that, as a hygroscopic material, wood tends to absorb or release moisture until it reaches equilibrium with the environment. This is called the equilibrium moisture content (EMC) of the wood, and this value will vary from one job site to another, so flooring installers need to check their wood and the RH conditions at each job site.
If a wooden floor is installed too far away from the EMC values of the current installation location, a number of failures may occur, including:
Discoloration. In some wood floors, moisture can cause dark or discolored spots to appear. This ruins the appeal of the floor and can be a precursor to other flooring failures.
warping. As the wood begins to absorb moisture, the wood will begin to warp and pull away from under the floor. In most cases, the intervals are small. However, in some rare and extreme cases, the wood may completely separate from the flooring if there is an external source of moisture.
Crowned. When there is more moisture in the center of a piece of wood flooring than at the edges, the center will swell and form a small bump. This is called "crowding".
Cupping. When there is more water at the edges of a board than in the center, the edges may rise as the board expands. This can also cause the boards to push against each other, creating a wavy appearance.
Continuous water condensation. As wood floors release excess moisture, it can condense on the surface of the wood.
For flooring installers, any of these issues can cause a callback, which involves wasting a lot of time, labor and resources replacing damaged wood floors.
Therefore, it is important to perform a quantitative moisture measurement of the %MC of wood flooring. Also remember to take quantitative measurements of RH conditions at the job site to help determine the EMC of the wood.
Note: Since wood flooring installers can handle a variety of woods, simply having a "wood moisture meter" isn't enough. Even at the exact same moisture level, different types of wood will have different readings. Therefore, if the goal is to achieve quantitative moisture measurements, it is important to consider corrections for wood species. Some high-end wood moisture meters have built-in species correction, while other users will need to make manual adjustments using a species correction chart.
