| Aspect | Kiln Seasoning | Air Drying | |--------|----------------|-------------| | | 4–60 days (species dependent) | 3–24 months | | Final MC | 6–12% (indoor use) | 12–20% (outdoor only) | | Insect/fungal risk | Eliminated (heat kills pests) | Remains possible | | Space required | Small footprint | Large yards | | Control | Precise, repeatable | Weather dependent | | Cost | Higher energy/capital cost | Low cost but slow |
Kiln seasoning involves heating the wood in a controlled environment to a temperature that is high enough to evaporate excess moisture but not so high that it causes damage to the wood. The process typically involves the following steps: kiln seasoning of timber
Slow at the start, fast only when safe, and always condition at the end. | Aspect | Kiln Seasoning | Air Drying
Kiln-seasoned timber is used in a wide range of applications, including: fast only when safe
| Defect | Cause | Prevention | |--------|-------|-------------| | | Too fast drying early | Lower temp, higher humidity | | Internal honeycombing | Surface hardened, core stressed | Reduce drying rate, condition early | | Collapse | Cell wall buckling (wet wood) | Low temp initial, pre-steaming | | Casehardening | Uneven MC gradient | Final conditioning treatment | | Warp (bow/twist) | Uneven restraint or grain | Good stacking, weight on top | | End splitting | Rapid end-grain drying | Seal ends, slow initial drying |