Wood shrinks and warps as it continues to dry. Ever build a table and look at the top… there are gaps in places there weren’t? Cracks that are new? A slight warp that grew more and more over time? In fact, boards that are freshly cut from a log (green lumber) will shrink and warp considerably as they dry. Keep this in mind as you consider live edge lumber. Woodworkers, for practical purposes it’s better to think in terms of using lumber that has been pre-shrunk and pre-warped. In other words, I want the wood to shrink and warp before I build a piece of furniture with it, not after.
So, how do I know for certain that the lumber is dry enough for use? I measure the moisture content with a meter. For the most accurate measurement, I cut a small amount off of the end and poke the prongs of the meter into the center of the board. Testing the moisture content on the outside of the board is misleading because the moisture content can fluctuate daily on the board surface as it is always striving to find an equilibrium with its environment.
So what is the recommended moisture content for lumber for furniture projects? I shoot for 7 to 8 percent moisture content. The target is a moisture content that places the lumber in balance with the relative humidity in my home (or the location in which the furniture will eventually be placed). Drying the lumber to a level that’s in balance with the home minimizes the shrinking and warping that occurs after the piece of furniture is constructed as lumber naturally seeks an equilibrium with its environment.
How does live edge lumber get to that moisture content level so it is safe to create furniture? That is where a kiln comes into play. All the live edge lumber is placed into a kiln to slowly remove the moisture from the lumber with intense heat over time. This allows the lumber to dry without risk of cracking, later shrinking or starting to warp as it ages. As the lumber is loaded into the kiln it is weighted to prevent warping as moisture is slowly removed. This process takes anywhere from 4 to 6 weeks depending on the lumber, the thickness and the moisture content that it contains.
All of our live edge lumber is air dried to lower the moisture content so that it is safe to kiln dry. After its brief stay in the kiln it is then stored in a covered building waiting on its permanent home. Live edge lumber can be used as it is from the mill or planed, and or sanded. However you select to use it; live edge wood creates a beautiful look in your home or business; but, it must be properly cared for ahead of time if it is going to stay beautiful for years to come.