Moisture’s effect on Wood

imageYou must remember that wood is a natural product processed from living trees. One of the natural properties of wood is its ability to constantly expand and contract. Wood will release or absorb moisture through the conditions of its exposed environment. This natural characteristic of wood is known as hygroscopic. Knowing that wood is hygroscopic is to understand that wood will achieve a moisture content equilibrium between its current moisture content and the moisture content of its changing environment. Wood is a significantly, dimensionally, unstable material in uncontrolled environments.

Meridian Products purchases its wood from reputable lumber sources. All lumber is inspected for moisture content before the wood is processed in our facility. We process all wood materials at 6.0% to 8.0% moisture levels.

The application of finish (clear topcoat or paint) does not prevent moisture exchange. All finishes are impervious and act as
a barrier to slow down moisture absorption or release. Unfinished wood is extremely susceptible to the effects of moisture. Do not leave unfinished doors exposed to opposing moisture conditions. Storage of product, finished or unfinished, may have a detrimental effect on the wood’s stability.

Once installed, wood products can show diverse evidence of effects from moisture. A section of installed cabinetry can show no signs of wood movement while areas around the sink and windows can be affected. Product installed in close proximity to HVAC ducts can be affected as well. Moisture-rich environments such as humid climates, waterfront properties and non-air-conditioned homes may create significant fluctuations of moisture content in wood. Heating a residence in the dry, cold months of winter can extremely reduce the wood product’s moisture content.

The expansion and contraction of wood due to environmental moisture conditions may cause non-warranted defects such as:

  • Open joints
  • Unfinished wood exposure on finished product
  • Bowing, warping and twisting
  • Sizing variations and/or excessive or insufficient spacing around pre-fitted product
  • Rails expanding or shrinking past the ends of stiles
  • Panel expansion or shrinkage (exposing stain lines where panel meets stile)


Meridian Products will not be held liable or responsible for any warranty issues caused by moisture.