Firewood: Getting Ready for Winter 2019-2020!

Posted: November 20, 2018

After a long, hot, and, in some places, a wetter than normal summer, it seems autumn has finally arrived. Perhaps your thoughts are turning toward evenings warming in front of the fireplace or cozying up to the woodstove.

The US Energy Information Administration estimates that about three percent of all Pennsylvania households depend on wood as a primary heat resource. Updated census data in 2017 found that there are nearly six million households in the state, meaning that about 170,000 homes use wood for heating; however, very likely many more use some wood to supplement their heating demands.

Those folks who burn wood for heat know the mantra that it should be cut to length, split, stacked off the ground, and covered for at least nine months to be dry and ready to burn. Preparing firewood well in advance ensures that its moisture content will approach 20 percent. At this level of dryness, there are fewer issues with creosote formation in the flue, and this certainly reduces risks of chimney fires. As well, the heat gained by burning dry wood over uncured wood is significant. Clearly, there are advantages to thinking a year out if you gather your own firewood.

An important part of firewood preparation involves cutting to length and splitting. Doing this exposes more surface area, which enhances water loss from wood cells. Stacking is also important, as it promotes air movement across the exposed surfaces. Finally, covering, so air is free to move through the stack, keeps precipitation (think rain and snow) from continually wetting the wood.

Undoubtedly, many Pennsylvanians gather their own firewood on privately held forests or on state forests with appropriate permits. This is arduous work; but at the same time can be enjoyable. However, firewood gathering involves risks. A research paper published in Advances in Emergency Medicine analyzed nearly 116,000 chainsaw injures requiring emergency room visits between 2009 and 2013 in the United States . They found that, “Most injury visits occurred among males (95%) and persons aged 30–59 years and during the months of September through November. The main body sites injured were the hand/fingers and knee.”* If you are going to cut and move firewood, please make sure you understand how to use the necessary tools, always wear appropriate and approved safety equipment, and understand your personal limits and skills.

Interestingly many firewood gatherers focus on taking dead trees out of the forest. Research has repeatedly found that many of Pennsylvania’s privately-held forests could benefit from leaving more dead wood in place. Standing dead trees contribute important habitat for many wildlife species. Standing dead trees (snags) and dead parts of live trees offer both room and board for many kinds of wildlife. Tree cavities in live or dead trees are used by 35 species of birds and 20 species of mammals in Pennsylvania. Rotting and decaying wood on the forest floor provides cover and protection to many salamanders. At least 19 kinds of salamanders and 26 species of reptiles make some use of logs, stumps, bark, and slash piles in Pennsylvania's forests. Ecologists believe dead wood is one of the greatest resources for animal species in the forest. (For more information on Dead Wood and Wildlife, visit the website.)

If deadwood is so important to wildlife, what makes good firewood? If you are thinking ahead and preparing firewood for next year, cutting live trees is really the way to go. By cutting live trees there is the opportunity to improve growing conditions for trees that remain. Individual trees in a forest compete for growing space to expand their leaf area. When tree crowns are “tight” up against each other and they move in the wind, they collide and, in the process, physically define their space – some trees gain more space and others lose. Understanding this, a firewood cutter can choose to provide space to a tree they want to improve by cutting a competing live tree.

Making decisions about which trees to leave involves many considerations. Note the point is which tree to leave, not which to cut. The tree left will continue to grow by increasing its crown area. A firewood cutter can “take the worst first;” leaving the best to grow. The tree cut might be selected by: crown condition, stem quality, defects, and species. Species is purposely last. A quick web search will find plenty of listings showing heat value per cord by tree species. Interestingly, all hardwood tree species have about the same number of BTUs per pound of wood – about 8,600. The important variable is pounds of wood per cubic foot, which can vary a lot. For comparison, a cubic foot of dry sugar maple weighs 44 pounds and basswood is 26 pounds. A pound of sugar maple has as much heat as a pound of basswood – you will need a larger volume of basswood.

To learn more about how cutting firewood can improve our forests the US Forest Service has a very helpful guide titled “Improve your Woodlot by Cutting Firewood.” 

* Epidemiology of Chain Saw Related Injuries, United States: 2009 through 2013. Advances in Emergency Medicine Volume 2015, Article ID 459697, 4 pages. 

Contact Information

James Finley, Ph.D.
  • Professor Emeritus of Forest Resources
Phone: 814-863-0402