One of the biggest problems people who use wood burning stoves or fireplaces encounter is burning wood with a moisture content that’s too high. On the surface of it, you might not think wet wood is a big problem, but there are actually a number of problems it can lead to.
First, the rule of thumb is that the higher the moisture content, the less heat the log will produce. That’s especially bad in areas with cold winter climates where every degree of heat matters. Unfortunately, that’s not the worst of it. There’s also the problem of smoke. The higher the moisture content, the more smoke you’ll get.
Smoke can be a devastating issue in a fireplace or wood burning stove. For one thing, there’s the mess to contend with. Inevitably, some of the smoke will find its way into the house, and the soot from the fire will wind up coating everything, and cleanup can be a real chore. Even that though, isn’t the worst of it. The smoke also leaves a film on the face plate of the stove or fireplace, and in the flue. Never mind the aesthetic issue, this buildup can pose a real risk to your family because it is flammable. Unless you’re diligent about cleanup and keeping that buildup to a minimum, it can ignite. People have seen serious property damage and even lost their homes because of this problem.
For all of those reasons, it’s important that the wood you burn have a moisture content as low as possible. There is a fairly simple “test” you can conduct to get a sense for the moisture content in firewood. Simply bang two pieces together. If the sound you hear is a resounding crack (think of the sound you hear at a baseball game when the batter knocks one out of the park), you’re dealing with seasoned wood. If the sound is a wet thud, there’s a relatively high moisture content in it. This “whack test” however, doesn’t give you a precise readout. For that, you’ll need to rely on technology. This was the reason that the log moisture meter was invented.
They don’t look like much, but they’re actually incredibly handy devices. Using them is a lesson in simplicity itself. Nearly all firewood moisture meters come with two metal “prongs” on one end. These prongs are inserted into the log you’re testing. When you activate the device once it’s attached to the firewood, you’ll get a readout on the machine. Most firewood moisture meters these days have a digital readout, but you’ll occasionally find one with a meter and needle. The end result, however, is the same. You’ll get a fairly accurate measure of the moisture content of the fuel log in question.
The “sweet spot” you’re looking for is a moisture content of 25% or less. Consider any firewood in that range to be “seasoned” wood. Anything more than that, and you’ll want to let the wood dry further, or, if your need is immediate, then pick the fuel logs with the lowest moisture content and burn those, but understand that you’ll have sub-optimal heat and smoke/buildup issues to deal with.
Log moisture meters are generally inexpensive, and good investments, especially if you rely heavily on a wood burning stove or fireplace for home heating. Considering the risks involved with burning wet wood, you can look at the moisture meter as being cheap insurance. Not only will it mitigate your risk of smoke buildup and the fire hazard it can pose, but you’ll also ensure that you get the most heat out of every fuel log