Q.
What is the correct way to store wood stock? My boss has the shop store it vertically, but when you get to the last of it, it's warped. All the guys think it should be stored horizontally. Who's right?
A.
If it is dry, it cannot be bent and warped; if you have wet stock, or if dry stock gets wet, it will warp.
If we assume that you have dry lumber but a damp floor, then the problem is the damp floor and not how you stack the lumber. For the sake of discussion, however, if you were to stack it vertically in this instance, only the ends would get rewetted, so the warp that might occur would not be noticeable to most people.
Gene Wengert, forum moderator
Please correct me if I have made any false assumptions (i.e., that bow is not the same as warp, etc.).
You can take a dry piece and lay it flat, support it at the ends and let it sag in the middle (no other load). After a year, you can look at it and when you put it on edge, any apparent warp will be gone (or will be so slight that it is not important).
Properly dried wood is just too stiff and too strong to bend easily without adding a considerable amount of weight. Book shelves stay flat for years unless they're loaded with lots of books.