How Long Will Firewood Last Outside?

There’s been times where I’ve looked at my firewood pile and thought there’s no way I’ll be able to burn all that wood. For some reason, I always seem to go through more wood than I think. That’s why it’s always better to have too much wood than not enough, but doesn’t firewood rot? How long will firewood last outside?

Firewood will last at least 3-4 years if it’s on a rack and up off the ground. Covering up the top of your wood and leaving the sides exposed can extend its useful life for decades. Wood only rots when its exposed to water. It can rot in a single winter if it’s left on the ground uncovered.

So keep your wood up off the ground and dry unless you plan on using it in the next couple of months. Keep reading to find out the best way to stack and store firewood to extend its life.

How Long Does Firewood Last Outside?

This is one of those questions that’s impossible to answer without knowing some background information. How long your wood will last depends entirely on how well it’s seasoned and stored. Firewood piles normally fall into one of 5 categories.

  • Left In Log Form: Logs dry out and rot way slower than smaller pieces of firewood. Researchers have estimated that an average sized tree will take 57-124 years to decompose depending on the diameter and species. Hard woods last longer than softwoods. It takes so long for the moisture level to change in large logs that the seasoning process doesn’t start until the logs are split.
  • Split And Piled Up: Wood that’s split and left in a pile will have vastly different seasoning/rotting speeds depending on where it’s at in the pile. The top of the pile will last 3-4 years. Middle and bottom of the pile may not last through 1-2 winters. Firewood needs sunlight to dry out and go through the seasoning process.
  • Stacked On The Ground: This one never made sense to me. Why would you take the time to stack firewood if you’re unwilling to get a free pallet and dollar store tarp. You could have stacked/seasoned your wood properly for less than $5 and 15 minutes of time. You shouldn’t stack wood on the ground. The bottom 6-12 inches of the pile will rot by the end of the first winter. Top of the pile should last 3-4 years.
  • Stacked On a Rack: Wood that’s stacked on pallets or a firewood rack will last 3-4 years in the optimal burn range and up to 7 years before it completely rots. It’s never too late to toss a tarp over the top of your firewood and stop the degradation process. Just make sure sides are left open to improve airflow.
  • Stacked On a Rack and Covered: Wood that’s stacked on a firewood rack and covered will last decades. It may never rot if you continue to manage moisture and pay attention to bugs/insects. Keep reading to learn a safe way to kill carpenter ants and termites.

There’s obviously a huge difference between properly seasoned/stacked wood and wood that’s left on the ground to rot. What’s the fastest way to season firewood?

Seasoning Firewood To Make It Last Longer

Seasoning firewood is surprisingly simple once you understand a few basic facts. To season your wood, you need to raise it off the ground, cover it up, improve airflow, and maximize sunlight. If you follow all those steps your wood will last a very long time.

You might be surprised, but wood never gets too old to burn. Think about some of the 100 year old barns that are still standing. Farmers that managed to fight against moisture stopped the natural degradation process. Your wood would probably outlast you if you could find a way to keep it dry and insect free.

Speaking of insects, I recommend using a boric acid based insecticide (Zap-A-Roach is my favorite) to kill carpenter ants and termite infestations. It’s non-toxic to humans/pets and perfectly safe to burn. Spray it anywhere you see bugs and they’ll track it back and infect their food supply.

So How Do You Season Firewood to Extend Its Life?

Your first step is to find a way to get the wood up off the ground. This will solve 90% of the rot and insect problem since most people will go through a wood pile within 4 years. Make sure you cover it up if you have lots of wood or think it will take a long time to burn.

1. Build/Buy a Rack

Stacking wood on free pallets or pressure treated boards is the cheapest and easiest way to get it up off the ground. That works well enough, but I recommend building/buying a firewood rack. It’s not that hard to build and you don’t have to spend more than $50. That’s less than it costs to take my wife/kids to see a movie (boy is it getting ridiculous).

Firewood racks aren’t all that difficult to build from scratch, but I recommend picking up a set of firewood rack brackets that you use with pressure treated 2x4s. I bought the Mofeez Brackets, but any of them will work so get whatever’s cheapest. It takes less than 5 minutes to screw your rack together and you can swap boards out when they look like junk in 5-10 years.

2. Cover Up The Wood

You also want to use a cover on top of your rack to keep prevent pooling and water saturation. The vast majority of people cover their wood with a cheap plastic tarp (6×8 is perfect). That’s what I did for the better half of a decade, but I recently purchased a firewood rack cover.

I really like the REDCAMP firewood cover that I picked up recently, but I’m sure all the cheap covers are about the same quality. You can unzip the sides to make grabbing firewood easy and you don’t have to screw around with tarp straps. I’ve found that I’m way more likely to make a fire if I don’t have to fool around with a tarp.

3. Leave The Sides Open To Improve Airflow

This might sound counterintuitive, but you need to leave the sides of your wood pile exposed. The cool breeze will dry your wood out faster than the rain/snow can soak it. It might take 2-3 days for the ends of your wood to dry in the summer.

Look at how the tarp is placed in the picture above. The top keeps 90% of the snow off and only a few feet of logs are exposed to the snow. If you think about it only the ends of the logs are getting wet. The ends might rot after a few years, but most of the log will be perfectly fine.

4. Try To Maximize Sunlight

Set your firewood rack up in a spot that it will get a lot of sunlight. It’s kind of a balancing act between convenience and optimal rack placement. I recommend placing your rack in the sunniest spot within 20-30 feet away of your main entry door.

Most of my wood is back where I build campfires since that’s convenient in the summer. In the winter I move a 1/2 cord of seasoned wood into the garage at a time. Just make sure you check the wood for bugs and use a boric acid based insecticide (Zap-A-Roach is my favorite) to kill them before bringing it in. It’s non-toxic to humans/pets so it’s perfectly safe to burn.

Why Is It Bad To Burn Wet and Rotten Wood?

Burning rotten wood isn’t bad from a health and safety perspective, but it’s not ideal. The natural degradation process sapped most of the energy and fuel out of the wood. I would still burn the rotten wood, but the fires won’t be great.

Rotten wood burns fast at a low temperature and produces lots of smoke because of the excess moisture. Whether or not it’s worth burning is up to you. I live by a simple rule! Wood gets burned as long as I can pick it up without it falling apart in my hands.

You might need to dispose of firewood that’s rotten to the point where it crumbles. Check out my post describing what you should do with rotten wood.