You’ve got your log burner set up, your fire tools are arranged nicely, and the log man is delivering a new load any minute now. The problem is your firewood still needs seasoning. What’s the best way to reduce the moisture down low enough for a clean burn? We’re going to find out.
Why is Wood Wet?
Starting with the live product, trees suck up water through their roots and store it within the wood fibres in case of drought. Once a tree has been cut up for timber, the moisture level inside the wood will eventually equal the ambient moisture levels outside.
Wood is hygroscopic. This means it absorbs moisture from the atmosphere around it, so whatever environment the wood is in, it will absorb the moisture available in the air around it. So, if you keep wood with a moisture level of 25% in an environment with 10% moisture, it will end up with 10% moisture.
Why Does the Moisture Content of Firewood Matter?
Put simply, wet wood doesn’t burn as well as dry wood. Wet wood is harder to light, harder to keep lit, creates more smoke, and leaves more deposits inside your stove and chimney flue.
Dry wood is easy to light, will happily burn with minimal stoking, burns hotter, and creates far fewer airborne particles and deposits compared with the wet stuff.
If you want a “clean burn” when you light your stove, you need to reduce the moisture content of your firewood. This is achieved by “seasoning” your firewood.
What is Seasoning?
Just to be clear, seasoning firewood does not involve liberal amounts of salt and pepper. The term “seasoning” refers to the process of reducing the moisture content of wood. So, whether you’re preparing expensive hardwood timber for fine furniture making, or drying out wet logs for burning, the end goal remains the same.
Depending on what type of wood you’re working with, the moisture content of a living tree can be anywhere from 8 – 25%, which at the high end is useless for firewood. Seasoning your firewood can be as simple as stacking it up against the side of your house, or as complicated as drying it in a specially designed kiln.
How to Store Your Firewood at Home
The firewood has arrived, and now it’s time to lay it out for seasoning. Probably the most effective home method for seasoning your firewood is with a log store. You can either make one yourself from pallet wood, or buy a purpose built enclosure for your firewood.
What’s the Best Spot for Seasoning Wood?
First things first, you need to work out the best place to keep your firewood. I like to keep mine close to the back door because there’s nothing worse than a chilly trip to the bottom of the garden when you want to build up the fire.
The name of the game when it comes to seasoning wet wood is good air flow. Place your log store or wood pile somewhere as dry and well-ventilated as possible. Level ground is important to stop your stack from falling over and try to keep the area clear of leaves and other stuff that can block the free flow of air around your firewood.
If you can site your log pile against a south facing wall (in the northern hemisphere), it will catch more sun and season your logs a bit quicker. Combining good airflow with a little sunshine and protection against rain and moisture is the ideal setup for seasoning your firewood.
I find that the best spot in my garden for a firewood pile is up against the side of the house where it’s protected on one side, and partially by the eaves of the house above. It doesn’t get in the way and it’s easy to get to when I need it.
Try to avoid stacking a log pile underneath a tree that drops its leaves in the autumn, as they can smother your firewood and when the leaves rot, they can rot the firewood underneath as well. Make sure to leave a gap between the firewood and the wall as well, as this can slow down the drying process.
Give Your Firewood a Platform
As we have established, good airflow is the most important factor in seasoning firewood. The best way to increase airflow is by leaving lots of gaps.
Raise your log pile up off the damp floor with a platform, because firewood will absorb moisture from the ground as well as the air. You could use a purpose built log rack or something as simple as an old pallet. It doesn’t matter so long as the firewood isn’t touching the ground.
If you’re making your own firewood seasoning platform from timber, use the pressure treated stuff that’s not going to soak up moisture from the ground as quickly. Pallet wood is normally heat treated and won’t allow moisture to seep through.
The Best Way to Stack Firewood?
Got a huge pile of logs to season? The most efficient way to get them dry is with a wall of logs. You can stack them up all in the same direction or alternate the layers like a firewood game of Jenga. Take a look at some log pile art if you want some inspiration to transform a pile of wood into something a bit more interesting.
Starting at one end, build up a pile in a staggered pattern, a bit like brickwork. This should create a stable pile and allow for the all-important airflow around the firewood. Work your way along, building up the layers as you go, until you either run out of firewood or patience.
The last step is to cover over the pile to keep the rain, sleet, and snow off it. Some people don’t think this step is necessary, as only the top layer of firewood will get wet, but it’s good practice to try and keep the moisture away from your logs.
If you have a purpose-built log store, then there’s a roof over your logs already. If you’ve just piled up your logs, then a tarpaulin over the top will keep things nice and cosy inside. Tie down the corners but don’t forget to leave gaps for the air to flow around.
Now all you need to do is wait. In a well ventilated spot, out of the rain and with exposure to the sun, your dripping wet wood straight from the tree should be ready to burn cleanly within six months.
Check your pile with a moisture meter every so often, and you can enjoy your cosy evenings in front of the fire burning nicely seasoned firewood.