I've got several hundred feet of 4/4 lumber that I'm planning on storing in a pole building. It will be stored vertically, leaning against the walls. It is now kiln dry. During the summer, I can run dehumidifiers to keep the humidity down, so that the lumber won't regain moisture. But what about in the winter? I understand it doesn't take much heat to remove the moisture from the air, but does it matter if it's electric heat, or heat produced from a flame?
(Sawing and Drying Forum)
From Professor Gene Wengert, forum technical advisor:
Source of heat does not matter. Can you wrap the lumber in plastic so that no moisture can get into the pack? In this case, you would not need the DH unit in the summer either, to save electricity.
Regarding heat, it usually takes about 25 degrees F above the morning's low temperature, but you can put in a small electronic RH meter ($30 Radio Shack) and add heat until you get to the correct RH (perhaps 32% RH).
Why do you store vertically? It would seem harder to wrap and the lumber would be more open to having moist air move around it. Moisture change in cold weather is slower than hot, but it still occurs.