Suitable Moisture Content for Dead Stacking

Advice on when air-dried lumber can be safely dead stacked. May 13, 2013

Question
At what MC can I pull the drying material off the drying racks and dead stack to condense the pile and open up more drying space? I have heard that hardwoods are considered stable under 30% MC and should not mold, warp, etc. Can I dead stack at this point, waiting for a buyer, and then finish in the kiln, possibly 1-4 months? We mainly deal with western maple and oak. How about softwoods such as Doug fir and cedar - at what MC can we dead stack this material and consider it stable without creating problems?

Forum Responses
(Sawing and Drying Forum)
From Professor Gene Wengert, forum technical advisor:
I would feel comfortable dead stacking 4/4 and 5/4 under 22% MC average. This low value would assure that the core is also under 30% MC. With thicker stock, you need a bit lower MC to assure that the core is under 30% MC.

Note that dead stacking at 22% MC or even drier will result in plenty of time for any insects, if any are present, and there certainly could be, to do a lot of damage. So, dead stacking prior to kiln drying is often a poor idea.