Attic Lumber Drying

Tips on drying small quantities of wood in a warm attic. January 28, 2014

Question (WOODWEB Member) :
A while back I bought a used Woodmizer LT15 and have been milling pine to use on outbuildings on our farm. Occasionally I have acquired and milled poplar, walnut, oak, and maple. I have several stacks of those woods (4/4) stickered, covered, and air-drying.

I am a woodworker and would like to eventually use these woods in furniture. I have seen mention of finishing off the drying process in an attic. I am getting ready to build a new climate controlled shop and thought about incorporating attic space for wood storage and finish-drying. Does that make sense for small batches of drying? Are there any pointers on the design of that space?

Forum Responses
(Sawing and Drying Forum)
From contributor R:
I dry a lot of small woodturning blanks in the attic of my house. If I was doing lumber, I would build a box on the first floor, and just take a duct up to the attic and draw that hot air down. That is like using the attic as a heat source. If you want to use the attic anyway, and are building, I would basically build a freight elevator with an electric winch, or buy one of those free standing car lifts. A guy puts enough mileage on the lumber, let alone hauling it up attic stairs too.

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From Contributor N:
You should be okay doing that. A friend of mine does and has a small fan nearby to constantly move the air around to improve drying time. Keep the area clean and sawdust free to avoid bug problems. If you have high figure woods it is still best to have it finished in a kiln to get it way dry to aid in keeping it flat when used. You can use wall space, even roof space if you keep it well supported; good to sticker it if it is at all moist.

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From Gene Wengert, forum technical advisor:
Insects in softwoods (used for framing most of the time) will not attack hardwoods (and vice versa). It is critical to keep the area free of debris. The attic should be closed in well (except for normal venting) so that you develop the higher temperatures and low RH. The main concern is the extra weight causing structural damage.

About air flow: You need only a small amount of air flow when using air dried stock. All you need to do is stir up the air. If you are not in a hurry, then no extra air flow is needed.

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From Contributor A:
Attic drying works for small amounts of wood. Be mindful of the structural concerns Gene mentions.

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From Contributor M:
Is heat (attic temps) enough? What happens to the moisture? Does it evaporate or absorb into the structure’s wood? I put wood in the upstairs of my shop but I am not sure that it dries any faster, but may have less moisture than outside drying. I think that airflow and air exchange is a key factor. Am I wrong?

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From Gene Wengert, forum technical advisor:
Attics are well vented. Shops are not usually. An attic can easily be 30 F hotter than outside. The moisture is small enough that it will not affect the wood structural items, and those pieces will dry out when heated anyway.