Isn't Hundred Year Old Reclaimed Barnwood Already Dry?
To answer the question, Yes, the barnwood is dry, but not dry enough. After we cut material from barn beams or prepare for making a floor, we take the next step and we kiln dry the wood. There are two reasons to kiln dry the wood.
Getting the Barnwood Dry Enough....
Our first goal of course is to remove the moisture from the wood. I often get the comment, “That wood is 100-plus years old. It must be dry.” That is true to a point. It’s dry compared to a new tree that’s been cut down, but wood has a certain amount of moisture content just by existing in the environment.
Where new wood might have 80% moisture, the moisture content of barn wood is usually 13-17%. That is pretty typical among siding, beams and other wood in the structure. Sometimes we find it even lower than that. It just depends on how exposed the wood has been to the elements. Our goal in kiln drying is to get the wood dry below a 10% moisture content.
We will get it below a 10% moisture content, which is good for most applications. But we usually end up around 5-7% when we are done. Our goal here is to make sure if we glue up a table top or lay a floor, we won't get gaps between the joints.
Cooking the Creepy Crawly Bugs...
The second reason we need to kiln dry the wood is to kill any potential eggs or bugs that might be living within the wood. Most of these barns over the years have been wide open exposed to the elements. They are open season for the bugs to get into and eat whatever they may eat. These barns are also favorites for spiders – some the size that you can barely even see.
In our kiln operation, once we have the moisture content down to the level that we need (which is that 5-7%), we turn the heat in our kiln up to about 130-140 degrees.
In the early stages of kiln drying the barnwood, we try to maintain right around 95-110 degrees. That’s where we’ve found the best rate to take the moisture out. But we crank up the heat in the last 24 hours so as to kill any potential little bugs or creepy crawlies that may be living within the wood.
It’s recommended to maintain at least 120 degrees for six hours. We take that a little bit further. We go up to 130 degrees and we maintain that level for at least 24 hours or even for a whole weekend. That way we can be sure that we don’t have to worry about any of the creepy crawly bugs.