Do you know what aspect of your lumber is perhaps more important than its species, its origin, and even its grade? The answer is the way the lumber has been dried. No matter how wonderful your lumber was for starters, if it’s dried too quickly, it can become worthless. But the damage caused by improper drying isn’t always obvious until the wood is already being installed. Improperly dried lumber can lead to costly difficulties and frustrating delays. While quality lumber can be used in various stages of wetness and dryness, a top-notch wholesaler will help you understand how the wood behaves and how to compensate for the movement it will probably experience.
Various Moisture Levels
Because J. Gibson McIlvain Lumber carries a variety of lumber that demonstrates an equally vast array of moisture levels, we can provide lumber to meet the needs of your specific project, whatever it may be. Some of the lumber we carry comes to us freshly sawn, containing between 25 and 50% moisture. Other lumber has been dried to European standards ranging from 12 to 15% moisture content. And domestic species have been air dried to anywhere between 10 and 25% moisture content. While we handle each category of lumber a little differently, the same basic process can be applied to each; the variation comes when we take a look at the amount of time it takes the lumber to become ready for sale and installation.
Slow, Steady Air Drying
J. Gibson McIlvain Lumber dedicates vast amounts of space to air drying lumber; sometimes, lumber sits in the air-drying yard for just a couple weeks; other times, it’s there for the majority of a given year. (The amount of time largely depends on how wet the wood is when we receive it.) The carefully stacked lumber has small spacers, referred to within the lumber industry as “stickers,” in order to allow for air circulation around each board. This stacked and stickered lumber allows for moisture to be released evenly. Wetter lumber will require a longer time frame for air drying. In order to prevent checking and cracking, something must be done to slow the movement of especially wet boards. In order to help slow the release of moisture from the cut ends, we typically paint the ends or apply wax to them.
Air Drying Prior to Kiln Drying
Even if boards will eventually be kiln dried, they can benefit from air drying, which is gentler on the wood and allows it to release the majority of excess moisture. Unlike kiln drying, air drying doesn’t cause the lignin to be set. The resulting distinction between kiln-dried lumber and exclusively air-dried lumber is that air-dried lumber will be less stable but softer and easier to work.
In our next post, we’ll look at some kiln drying basics.