One of the most important steps in processing reclaimed lumber is drying — reducing the moisture content to a level that's stable for interior or exterior use. There are two primary methods, and each has advantages depending on the application.
Kiln drying uses a controlled environment — essentially a large oven — to reduce moisture content over a period of days to weeks. We target 6-8% moisture content for interior applications and 12-15% for exterior use. The kiln also eliminates any insects, larvae, or mold present in the wood.
The advantages of kiln drying are speed, consistency, and pest elimination. Every board comes out at a predictable moisture content, and you can be confident it's free of biological contamination. For flooring, furniture, and any interior application, kiln drying is essential.
Air drying is the traditional method — stacking lumber outdoors with spacers (stickers) between each layer to allow airflow. It typically takes 6-12 months to reach equilibrium moisture content, which in Iowa's climate settles around 12-15%.
Air drying is gentler on the wood and can produce less internal stress than kiln drying. For large timbers and beams that will be used in exterior or semi-exposed applications, air drying is often preferred. It also costs less, which matters for large-volume orders.
At our facility, we use both methods depending on the end use. Most dimensional lumber and flooring goes through our kiln. Large beams and timbers destined for exterior applications are often air-dried. And for some specialty orders, we use a combination — air drying to rough moisture content, then finishing in the kiln.
When you order from us, we'll recommend the right drying method based on your project. It's one of the details that separates quality reclaimed lumber from wood that might cause problems down the road.