Stacking a Kiln: Tight or Spaced Out?

Lumber in a drying kiln should be close packed edge to edge. December 23, 2014

Iíve been looking/reading, finding opposing points of view about when loading a charge. Is it better to edge the boards up against each other or leave an air space? I have the same question on the ends of boards where a person may be adding two shorter boards to make the length of the kiln chamber. Should those ends be butted?

Forum Responses
(Sawing and Drying Forum)
From Gene Wengert, forum technical advisor:
Lumber should be tight, edge to edge. It was only 50 years or more ago when we did make a space and that was with piles 8 to 16' wide in a yard with millions of BF and poor air flow due to the large amount of lumber. A space today does not help drying and will reduce kiln capacity and thereby increase costs. If you read about spacing, it must be an old book or from someone that is out of date. End to end spacing is not needed for drying, but a small space might be needed to help unloading with a forklift.

From Gene Wengert, forum technical advisor:
Two short pieces can be butted, if needed, but maybe add a short sticker at the joint to assure both ends are well supported.