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hello there, I just have a quick question on causes of twist in kiln dried lumber.
I recently did a charge of 8/4 softmaple and noticed a bit of twist in the lumber.
some of the packs I noticed were not stickered properly, there were lots of gaps or air space in between pieces of lumber throughout each tier of the pack.
do you think this could be one of the reasons for the twist?
Twist results mainly because the sawmill cut the lumber at an angle to the grain. Perhaps it was a corrected log. Perhaps the mill cut parallel to the pith and not parallel to the bark. We can also cause twist of the stack's foundation is not flat. Finally, some trees have spiral grain which causes twist...soft male is not known to have this property.
I find that some times the sawmill will cut 8/4 out of 4/4 logs .Cant blame them far less sawdust but very hard to dry flat .watch that you dont overdry as well .If it 2 &btr ND maybe they can use it at 7-9 final MC.
I should have said
You said: "Twist results mainly because the sawmill cut the lumber at an angle to the grain..... Perhaps the sawmill cut parallel to the pith and not parallel to the bark. -
I've always thought that to get the best grade lumber from hardwoods to cut parallel to the bark and to get the best structural lumber to cut parallel to the pith. Can you explain more about your remark?
The more the grain (lengthwise) is parallel to the sides and face of a piece of lumber, the stronger the piece will be. Even a slight grain angle reduces the strength. So assuming stronger piece is better lumber, then sawing parallel to the bark as much as practical, is better.
Further, the closer this grain is parallel to the lumber to the lumber's shape, the less natural warp there will be. So, again, assuming flatter is better lumber, sawing parallel to the bark makes better lumber.