Moisture Effects
Affects of Moisture in Wood
- Any solid wood product will expand over time as moisture and climate conditions change
- Effects of moisture may include:
- Panel expansion
- Joint expansion or opening (especially on miter doors)
- Stile bowing
- Panel contraction (may result in ?white line? if finished)
- Stile/rail expansion
Southern or Humid Climates
- Southern or humid climates are especially susceptible to expansion due to moisture
- Locations include:
- Waterfront properties
- Coastal regions
- Gulf coast, especially Florida
- Marine applications, such as boats and yachts, are considered high humidity regardless of any climate control systems
- Non-air conditioned homes, regardless of location, are very susceptible to expansion due to moisture
- Winter and vacation homes should maintain some form of climate control, even in off-season
Tips for Avoiding Moisture-Related Problems
- Certain wood types, primarily Hard Maple, have a tendency to expand more than others. For details, see chart
- If expansion in doors occurs prior to installation on cabinet box, air conditioning will usually return doors to normal
Potential Wood Movement Chart
This chart indicates how much a 12" wide panel can change in size depending on moisture.
| Wood Type |
Width in inches at
5% humidity |
Width in inches at
14% humidity |
Wood movement in inches caused by 9% swing in moisture |
| Red Oak |
12 |
12.29 |
0.29 |
| Hard Maple |
12 |
12.27 |
0.27 |
| Soft Maple |
12 |
12.27 |
0.27 |
| Cherry |
12 |
12.23 |
0.23 |
| Hickory |
12 |
12.29 |
0.29 |
In general, Merillat manufactures its products at a moisture content of 6% to 8%, depending on the season.