High Humidity and Your Cabinets
Wood products in humid climates are especially susceptible to expansion due to the extra moisture in the air. The wood will absorb this moisture, causing it to swell or expand. If wood products are exposed to excessive moisture for an extended period of time, they may not resume to their original size. The key to controlling expansion and contraction is to control moisture in the wood by controlling the humidity. A common issue experienced with wood kitchen cabinet doors would be that they start to rub together. The minimum moisture content for decay to propagate is 22 to 24 percent, so building experts recommend 19 percent as the maximum safe moisture content for untreated wood in service. Water by itself does not harm the wood, but rather, wood that has consistent high moisture content will enable fungal organisms to grow.
Low Humidity and Your Cabinets
In low humidity conditions, wood will give off/release moisture and contract or shrink in size. During winter in colder environments, cabinetry will shrink from the dry heat produced by your home’s heating system. As the wood loses moisture, gaps will appear at the joints between the cabinetry pieces. Painted doors will also reveal seams at the joints as this natural movement occurs. Unfinished lines may appear around door panels. When the cabinetry regains its lost moisture under produced humidification or during the summer months, these gaps will often close and be less noticeable. This occurs with all wood products such as Kitchen Cabinetry, Millwork or Furniture, and will occur in any environment.
The ideal conditions for your wood cabinets is approximately 21-22°C or 70°F with a humidity level of approximately 35%-55%.