Burn dry wood to stay warm, save money, and be safe

You might ask- what does that mean and why should I care? Well, wood that is greater than 20% moisture content (or proof) will not burn efficiently, and that will mean wasted heat and increased risk of a chimney fire.
                                                                              
OK, so how do you get your wood down to 20 proof or less? By giving it time and space to dry; here’s how.
1. Nine to 12 months before you need the firewood- cut, split, and stack wood in piles that are one log deep and spaced one log length apart.
2. Cover the top of the pile with plastic to keep the rain out and keep the bottom layer up off the ground to increase air circulation (which also helps keep snakes away).

Next fall, use your kitchen oven and some math to measure your wood’s moisture content; that will tell you what “proof” it is. Here is how …
Cut a small (1” thick) piece from the middle of several logs from different sections of the pile. Use a kitchen scale to weigh each piece; this is its fresh weight. Label and record the weight of each piece in ounces. Dry the pieces in your oven set at 200 to 250 degrees until their weight no longer changes; that could take 12-24 hours. Weigh each piece again and record the dry weight of each piece. The difference between each piece’s fresh and dry weights tells you how much water was in the wood. Divide the weight of the water by the dry weight of the wood to find the moisture content of the wood in your pile. The formula is [(FW – DW)/DW]*100 = Proof of the wood. Wood is ready to burn when the moisture content is 20 percent or less.

Here is an example. The fresh weight of piece #1 is 5 ¾ ounces and its dry weight is 5 ounces. So the wood contained ¾ ounce of water when it was “fresh.” Divide the weight of the water (3/4 or 0.75) by the dry weight (5) and multiply that answer (0.15) by 100. So … inserting the numbers into the formula would give you [(5.75 – 5)/5]*100 = 15 proof wood. The proof of your wood pieces will vary but as long as they are mostly less than 20 proof then your pile is dry enough to burn.

Tip for parents- Clip and save this article for the next time your kids ask you what good is math anyway. Being able to do the math above promotes efficient wood burning that helps the environment, saves you money, and reduces chances of a chimney fire!

See many more tips on Forest Stewardship at http://vip.cas.psu.edu/News.html or call your county extension office. In Lackawanna County ask for the Garden Help line at 963-6842 or email LackawannaMG@psu.edu.

Terry Schettini, Extension Educator
Penn State Cooperative Extension in Lackawanna County