Join Date: Nov 2006
Location: Kansas, Illinois
Numerous issues with warped lumber and most have been mentioned here. When it comes to softwood, two big issues come to mind. First, as Daren mentioned, its new fast growth trees which have less strenght, but more importantly, location of the board in its relation to the log.
Making 2x4's out of 20" trees are bound to have a boat load of warped boards because the growth rings are not centered, or balanced on each side of the board. The same can be said for hardwoods.
Nothing worse than having a customer come in with a nice 20" log and tell me he wants it all cut into 2x4's. I wont do it anymore becuase even though I warn them of the warp issues from many of the boards they come back later and complain that 2/3's of the boards warped like bananas.
Take the same log and cut the lumber into wider boards, assuming its not fast growth stuff, and you will have far more stable lumber.
All these factors are assuming its stacked and dried properly which is a whole nother book :)