Keeping Wood Dry in Storage
How much heat is needed to keep stored lumber dry indoors? December 6, 2011
Question
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?
Forum Responses
(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.
From contributor D:
I store vertically, for 2 reasons.
1) I have a lot of vertical space, and this utilizes that, and
2) When people come to buy my lumber, it makes it easier for them to dig through it.
From Professor Gene Wengert, forum technical advisor:
Makes perfect sense (cents) indeed.
AI enhanced answer (added Feb 06, 2025):To keep stored lumber dry indoors,
temperature control is less critical than
humidity control. However, maintaining a stable environment can help:
-
Temperature: A temperature range of **60°F to 70°F (15°C to 21°C)** is generally recommended. This range helps prevent the wood from expanding or contracting excessively due to temperature fluctuations, which can lead to warping or cracking.
-
Humidity: More importantly, you want to keep the **relative humidity (RH)
between 30% to 50%**. High humidity can cause mold growth and wood swelling, while very low humidity can lead to wood shrinkage and splitting.
-
Ventilation: Ensure good air circulation to prevent moisture buildup. Use fans or dehumidifiers if necessary, especially in climates with high ambient humidity.
-
Insulation: Insulate storage areas to minimize temperature swings, which indirectly helps with humidity control.
In summary, while heat itself isn't the primary concern, maintaining a stable temperature within the suggested range, coupled with effective humidity control, will keep your lumber dry and in good condition.
