Air Drying Shed Design

A couple of basic tips, plus an example of a simple drying shed for rough sawn lumber. April 21, 2011

Looking through the archives for design tips on an air drying shed for a small operation has yielded the following: 1) They need good air flow under the deck. 2) 2' spacing between edges of the stacks. 3) 3' or better overhangs with gutters.

Our experience has been that most of the air drying degrade comes from too fast drying at the early stages, but I can see how it might need some controls for adjusting to the needs of the wood and the weather conditions.

I am thinking to leave the sides open with some kind of fabric that rolls down to stop wind driven rain and snow. Is this the best idea? Also, should the very bottom of the stack be a little higher off the floor than sticker thickness? Our floor is 20" off the ground and a vapor barrier is in place.

Forum Responses
(Sawing and Drying Forum)
From Professor Gene Wengert, forum technical advisor:
Shade-Dri is often used for curtains, hung like a shower curtain. Lumber should be at least 8" off the floor to allow for good air movement. The open area must be 8" and not blocked by the bolsters or other items. I think a lot of loss in air drying comes from wetting of dry lumber too.

From the original questioner:
Thank you Dr. Wengert - very helpful.

From contributor R:

Here is my shed, strictly for yellow pine building material. Has 3 bays for wood storage, each 10' wide with an 8' stock on the left, 10' in the center and 12' on the right. In each section there is a 50" space for stickered lumber, and then the remaining space for dried lumber.

Click here for higher quality, full size image

In this photo the building was pretty new. It now is holding a pretty good inventory. No batten strips on this shed, mainly for air flow and the drying process, yet the boards help protect from the wood getting soaked. In fact very little rain has ever entered through the boards. This photo, the curtains are down.

Click here for higher quality, full size image

From the original questioner:
Thanks for the photos. What are those curtains?

From contributor R:
They're just plastic roll-up curtains bought at the local home center.