Wood Storage: Vertical or horizontal?

Truly dry wood stored under the proper conditions will not warp, no matter how you position it. September 26, 2000

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?

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 forgive me when I ask you to repeat yourself, Gene. You say that the wood cannot be bent or warped when it is dry? Most vertically stacked wood is not really vertical, i.e. it is on a slight angle. It seems to me that the larger the angle, the more prone the lumber will be to bowing. For example, I would bet leaving a board at a 45-degree angle would bow it after a short time -- two weeks, perhaps.

Please correct me if I have made any false assumptions (i.e., that bow is not the same as warp, etc.).

Bow is one form of warp.

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.