Maintaining their natural beauty can be challenging, however—and it’s all about moisture content. If the moisture content of wood products stays within acceptable limits, maintenance is relatively easy. But managing wood’s natural response to changes in moisture content can be complex. Buildings often contain many wood components—from gymnasium floors, wooden stairs, and moldings to doors, cabinets, and wall or ceiling panels. Like most building materials, wood is hygroscopic, meaning it absorbs or releases moisture depending on the surrounding environment.
At the time of installation, it is generally assumed that wood products are within an acceptable moisture content range. According to industry guidelines, wood floors, cabinets, and doors should typically have a moisture content between 6% and 9%, which corresponds to an indoor relative humidity (RH) of 30%–50%. Maintaining this RH range consistently is critical. Because wood continually reacts to its environment, fluctuations in humidity can lead to long-term performance and aesthetic issues.
This basketball hardwood maple floor (above) had big problems that originated from too much moisture coming through improperly insulated walls during the wet winter months. The Ligno-VersaTec allowed checking for relative humidity and measuring the elevated moisture levels of the floor plank. The only remedy was to replace the floor because the floorboards were cupping.
Using a moisture meter and a thermo-hygrometer is considered best practice to ensure proper conditions are maintained. These tools help verify that wood floors, doors, cabinets, and wall panels remain stable and visually appealing for many years. A versatile instrument, such as the Ligno-VersaTec moisture meter with thermo-hygrometer, allows maintenance personnel to detect and track potential moisture-related issues throughout a building.
One of the key advantages of owning a moisture meter is the ability to record and compare measurements over time. Changes in moisture content can serve as early warning signs that a problem may be developing. Identifying these changes early enables maintenance teams to address issues before they escalate into costly repairs or structural damage. This preventative role is one of the most important functions of moisture measurement.
Moisture problems can originate from multiple sources, including elevated indoor relative humidity or moisture intrusion through walls, roofs, ceilings, or subfloors. Excess moisture migrating into floor coverings can significantly affect performance. That is true for wood floors, carpet, tile and even LVT floor coverings.
Moisture-related issues typically present in two ways. First, dimensional changes occur as wood absorbs or loses moisture, leading to shrinking, warping, cupping, buckling, or delamination. Second, when wood moisture content exceeds 16%, or when relative humidity remains above 60% for extended periods, conditions become favorable for mold growth.
Spores, the start of any mold colony are present anywhere. If enough humidity is available, spores will start to develop into mold. Therefore, conditions which favor mold growth have to avoided. The only reliable way to prevent mold growth is to keep moisture levels below the critical 60% RH threshold.
High or low humidity conditions may result from extreme outdoor weather, poor building design, or moisture intrusion through roofs, walls that are not constructed to code, or subfloors emitting excess moisture into the flooring systems. This is to be prevented for any wood floors, carpets, tiles and even LVT floors
Early detection of these issues is possible through the use of moisture meters and hygrometers. In large building envelopes, where moisture problems can originate from many locations, having a versatile moisture measurement system is essential. Lignomat’s moisture and humidity measuring kits with Ligno-VersaTec allow users not only to identify moisture problems early but also to trace them back to their source—even through walls that are five inches thick or more.
These tools can be your secret weapon in preserving the natural beauty of flooring on campus and keeping buildings safe and healthy as well. The advantages are clear—protecting your floors is more sustainable and helps private universities and colleges avoid the hassle, waste and expense of replacing flooring.
Understanding the EMC Chart
The Equilibrium Moisture Content (EMC) chart (see page 15) illustrates the relationship between relative humidity and wood moisture content. Following is an example how that chart can be helpful to predict wood moisture changes: If a wood floor is installed at 6% moisture content and the building’s relative humidity rises to 60%, the floor will gradually absorb moisture until it reaches approximately 11% moisture content. Depending on the wood species, this increase can cause significant dimensional changes. When hundreds of boards expand side by side, the cumulative effect may lead to floor buckling. On the other hand, if conditions persist, there is a danger of potential mold growth.
