Controlling Wood Movement

This month, our blog post covers a subject that is critical to anyone working with wood – the successful installation of millwork and doors, especially as it relates to moisture. This fact sheet should prove helpful. It’s text is below, but here is a PDF version for those who prefer it.

Wood Versus Moisture

Some of the most common quality issues seen in the millwork & door industry arise from the wood taking on too much moisture.

Wood is a hygroscopic material, meaning it absorbs and releases moisture as a result of the changes in relative humidity in its surrounding environment.

Wood is always undergoing slight changes in moisture content; however, normal seasonal changes in the moisture content within a properly controlled interior are not enough to cause serious dimensional change, if doors & millwork are properly cared for during the installation process.

Following a few simple guidelines will provide you and your customer the best opportunity for a successful, quality installation with fewer callbacks.

Keys to a Successful Installation

  • Site should be fully enclosed and protected from the elements.
  • HVAC must be up and running with the temperature maintained between 68 and 72 degrees. Relative humidity should be maintained between 30% & 45%.
  • Make sure that all “wet work” has been completed before delivering wood products to the job. Never store material in areas with newly poured concrete or in rooms that have been recently dry walled or plastered and never store material on fresh concrete , in the garage or basement .
  • All surfaces of doors must be properly sealed, including the top and bottom, to prevent the warranty against warp & twist from being void. Once the process of finishing a door has started, it is crucial that it is completely sealed without starting & stopping for extended periods of time.
  • Never install a pocket door prior to finishing. The average moisture content in framing material can range from 15% – 19%. An unfinished door which is installed and then pushed back into the wall opening, will absorb the moisture from the framing material, which will cause the door to warp and/or bow.
  • Always store doors flat or in an upright, vertical position. Never lean doors against a wall.