Does Speed of Drying Affect Flooring Stability?
Will wood that is dried more slowly be more stable in service? Not necessarily. April 18, 2010
Question
Is there any logic to the statement that the slower oak is dried, the more stable it is later? I'm looking for a source of really wide white oak flooring (8"+) and get conflicting info from suppliers.
Forum Responses
(Sawing and Drying Forum)
From contributor M:
I like to see oak aged/air dried/relaxed for 6-9 months before going into a kiln.
From contributor S:
We have been making wide plank floors for years (8"-12"). My feelings on drying hardwoods are simple: the MC needs to be 6-8%. Wood dried in a steam kiln has a greater chance of stress put in during drying than a dehumidification kiln. Does green dried oak move more than air dried before drying? I haven't noticed any difference. White oak has more twisted grain cells than red oak has, so twisting, cupping, moving might be more. Also, the wider the floor, the more surface area is exposed to moisture changes once installed. So to answer the question, if the wood is dried to the kiln schedule and to the right MC, you should be fine.
From Professor Gene Wengert, forum technical advisor:
All size changes are related to MC changes, so proper drying to the correct final MC will minimize size changes in use. The speed of drying (KD green from the saw or air drying a year and then KD) has nothing significant to do with stability. What you quoted about speed and stability is a statement that pops up every so often but is not true. I am not sure where it came from unless slow, long drying assured that the final MC was correct, compared to fast drying where the final MC could be variable.
