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Ask a pro: Drying lumber
I recently had some white birch logs milled into rough-sawn lumber. I have approximately 100 board feet of 5/4 boards that are 4" to 7" wide and 8' long. I stacked them under cover with 3/4" stickers between each layer.
Do I need to have the boards kiln-dried in order to use them to make furniture, or is air-drying sufficient? If so, how long do I wait? - Alan Smale, Orillia, Ont.
Air-dried boards are fine for making furniture. Of course, kilns bring lumber to an optimal moisture content, about seven per cent, much faster than air drying.
With a proper set-up, a moisture meter and the diligence to check your wood once a month, you can air-dry your lumber down to below 20 per cent and use it for your own projects. Besides using stickers in the stacks, coat the ends of each board using latex paint. This step will even out the drying and reduce checking marks.
As for time, it generally takes one year per inch of lumber thickness, but you can speed up the drying process by circulating air over the boards, using a fan, and rearranging your stack periodically.