Building a Barn with Green Lumber
by Jim Taylor
I'm interested to find out if I can build a post and beam barn out of fresh cut timber harvested on sight. It would be used for a small family farm with horses, goats, chickens, pig.
Thank you for your question, the answer is it depends. We use green lumber in our barn kits, but we choose a specific species (White Pine) that seasons very well, it doesn't bend, warp, or twist as much as others and it shrinks very little, and any cracks from drying are very small.
Other species such as hardwoods like oak, maple, hickory, elm, etc. all have different properties but all of them can be used "green."
The important thing with any of these species is to handle them correctly so that they dry slowly. All of the bad things that happen to wood happen because moisture is removed too quickly.
It is a bad idea to kiln dry your timbers for timber framing. Kiln drying is too quick for large timbers. They will loose strength and may crack, bend, or warp.
Of course the best thing to do is to air dry your timbers over time, but it can take as much as 6 months per inch of thickness to completely season your timbers. Who has time for that?
Of course if your barn is already built then your timbers can dry in place, that is the way that they did it 100 years ago. The barn builders and farmers of old would do all of their cutting in the winter, not only because everything was frozen and easier to get to but also because the trees were dormant. It was the time of year when there was the least amount of sap in the tree. If you start out with a dryer tree than you will have less trouble dealing with moisture when you build.
Once you have cut your trees down in the winter, you can either start sawing them into square timbers or store them by stacking them off the ground. If you are using hardwood you will want to paint the fresh cut ends to prevent them from drying too fast. If they dry to fast the ends may crack and you could end up with a foot or more of waste on either end.
Anytime you need to store your lumber for more than a week or so, you will want to stack it with one inch by one inch sticks called "stickers" between each layer of lumber. Place the stickers 3' apart starting at one end of the layer ending at the other end.
You can find more information in my book.
Another great book, an one I highly recommend is called A Timber Framers Workshop. It can be found on Amazon.