Firewood is seasoned when the inside of a fresh split reads 20 percent moisture or less on a pin meter. That one number decides how much heat you get, how much smoke drifts back into the room, and how fast creosote builds inside your flue. This guide is about getting a pile of wood to that number and keeping it there through a Colorado winter.
The Front Range is one of the easiest places in the country to dry wood. Our air is thin and dry, the sun is strong, and the wind rarely quits. The trap is that the same climate makes wood feel dry on the outside long before it is dry in the middle.
We sweep a lot of chimneys around Aurora and Denver, and the difference between a flue that needs a light brushing and one packed with glazed creosote is almost always the wood. For which species to burn, read our guide to the best firewood for Colorado. This one is about getting whatever you have dry and keeping it that way.
What Seasoned Means in Numbers
A freshly cut tree is roughly half water by weight, and cottonwood is wetter still. Seasoned means that water has left the cell walls and the wood has settled between 15 and 20 percent. Below about 12 percent is rare outdoors, even here.
The number matters because water does not burn. Every pound of water in a log has to boil off before the wood around it can reach flame temperature. That steam cools the smoke and lets unburned tar condense on the tile or liner. That is creosote, and wet wood is the fastest way we know to make it. Our guide on preventing creosote buildup covers the chemistry; the short version is that a 30 percent log leaves noticeably more deposit than a 20 percent log from the same tree.
How to Measure With a Pin Meter
An inexpensive two pin moisture meter is the one firewood tool we recommend every wood burner own. Technique matters more than brand.
- Pick a piece from the middle of the stack, not the top row that has been baking in the sun.
- Split it fresh. The outside dries faster than the core, so a reading on the bark or an old cut face tells you nothing useful.
- Press the pins firmly into the fresh face, parallel to the grain, about a third of the way in from the end.
- Take two or three readings on this piece and a second one. Use the highest number, not the average.
- Test at room temperature if you can. Most meters are calibrated near 70 degrees, and a frozen log reads several points low.
Highest reading 20 or under, burn it. Low to mid 20s, it will burn but smoke. Near 30 or above, back on the stack for next year.
The reason the number matters is simple. Wet wood spends its heat boiling water, smokes and hisses instead of burning, and sends cool, moist smoke up the flue where it condenses as creosote. Our guides on preventing creosote buildup and the difference between soot and creosote cover that side of it, and our smoky fireplace guide explains why wood is the first thing we check when smoke rolls back into a room. This article stays on the woodpile.
How Long Front Range Species Take to Dry
Drying time depends on species density, how early and how small the wood was split, and how much sun and wind the stack sees. The figures below are typical for a single row stack in the Denver metro, top covered, sides open. A packed double row in the shade can take twice as long.
Table 1. Typical seasoning times for common Front Range firewood species, split and stacked in the open
| Species | Typical months to reach 20 percent | Notes |
|---|---|---|
| Ponderosa pine | 6 to 9 | Dries fast. Pitch pockets hold moisture longer than the surface suggests. |
| Lodgepole pine | 6 to 9 | Mostly beetle kill locally, often arrives partly dry. Test anyway. |
| Aspen | 6 to 10 | Quick to season, but soaks water back up if left uncovered. |
| Cottonwood | 9 to 12 | Very wet when green and stringy to split. A full summer, sometimes two. |
| Ash | 9 to 12 | Lower starting moisture than most hardwoods. Forgiving if split early. |
| Oak | 18 to 24 | Dense and slow. Fall bought oak almost never reads under 20. Plan two summers. |
Two caveats. Split size changes everything: a wrist thick split of oak may be ready in a year while a quarter round takes two. And a stack on the south side of a garage in Aurora can beat these figures, while the same stack on the north side under a spruce can miss them by half a year. The rule we give customers: softwoods split in spring are ready by the first cold snap. Hardwoods split this spring are next winter's wood.
Colorado's Advantage and Colorado's Trap
At a mile high, afternoon humidity in summer often drops into the teens. Add strong sun and steady wind off the foothills, and wood loses surface moisture faster here than almost anywhere east of us. A stack that takes two summers in Ohio often takes one in Denver.
The trap is the word surface. Water leaves wood from the outside in. A split that has spent six weeks in July sun will feel dry, sound dry, and show checks in the ends while the core is still well over 30 percent. Most people who tell us their wood is seasoned judged it by feel. The meter on a fresh split disagrees more often than not.
Monsoon Rain and Rewetting
From mid July into early September, afternoon storms roll off the mountains and dump heavy rain in short bursts. An uncovered stack drinks that in through the end grain, and because nights cool quickly, not all of it evaporates before the next storm. Water in the checks works deeper each cycle. Winter repeats the problem: snow melts on a sunny afternoon, soaks in, and freezes that night, and frozen wood burns worse than wet wood. Keep the top covered year round.
The Correct Stack, Step by Step
A good stack is a drying machine. It uses gravity to shed water, wind to carry away moisture, and sun to add heat. Here is the order we build ours.
- Get it off the ground. Two parallel runners of treated lumber, pallets, or landscape blocks, so the bottom row sits at least four inches above soil.
- Split early, split small. Split rounds within a few weeks of cutting, before the ends seal over. Aim for four to six inches across the face.
- Build a single row. One split deep, so air passes over every face. A second row needs a foot or more of gap.
- Stack bark side up. Bark sheds water. It matters most on the top rows, where rain would otherwise sit on open grain.
- Point the ends into the prevailing wind. Along the Front Range that is usually west or northwest. Water leaves through the end grain, so the ends face the breeze, not a fence.
- Leave the sides open. Never wrap them or push the stack against a solid wall.
- Cover only the top. Roofing metal, plywood, or a tarp cut to width, weighted down, overhanging by a couple of inches.
- Cross hatch the ends. Alternate split direction at each end so the column stands on its own in a wind event.
Build it in spring and burn from the far end in fall, oldest wood first.
Storage Mistakes We See Every Season
Most bad firewood we encounter was split correctly and then stored wrong.
Table 2. Common firewood storage mistakes, what they do to the wood, and the fix
| Mistake | What happens | Fix |
|---|---|---|
| Tarp wrapped tight around the whole stack | Traps moisture, blocks wind, grows mold. Wood often ends the summer wetter than it started. | Cover the top only. Leave sides and ends open. |
| Stacked against the house | Holds moisture against siding, invites ants and rodents to the foundation, gives wildfire embers a fuel ladder. | Several feet from any structure, farther in wildland interface areas. |
| Stored in the attached garage | Insects in the bark emerge indoors. Little airflow, so wood dries slowly. | Store outdoors. Bring in a day or two at a time. |
| Buying green wood in October | Wood cannot season in cold, short days. It burns wet all winter. | Buy in spring or early summer. In fall, buy proven seasoned wood and test it. |
| Stack on bare dirt | Bottom rows rot, wick water upward, and become a termite highway. | Runners or pallets, four inches of clearance. |
| Solid block stack in the shade | Center pieces never dry. Outer pieces look fine and fool the owner. | Single rows in sun with gaps between them. |
One more: piling wood on the hearth as decoration. The clearance rules around a hearth exist to keep combustibles out of that zone, and a stack of split pine is exactly that.
Bugs, Rodents and Why Wood Should Not Live Indoors
Firewood is habitat. Bark beetles, carpenter ants, wood boring larvae, spiders, and the occasional mouse all treat a stack as home. Outdoors the cold keeps them dormant. Indoors, next to a warm stove, dormancy ends within hours, so firewood should be inside for no more than a day or two before it burns. A small rack holding one evening's fuel is plenty. Do not spray firewood with insecticide either, since you will burn it and breathe the result.
Rodents connect back to the chimney more directly than people expect. A stack against the house is a mouse apartment with a short commute to the foundation, the attic, and sometimes the flue. If you already hear scratching, our page on birds and animals in the chimney explains what is likely in there.
Buying by the Cord: Local Terms and Checking a Delivery
Firewood around Denver is sold by volume, and the terms are loose in everyday use.
- Full cord. A tightly stacked pile 4 feet high by 4 feet deep by 8 feet long, 128 cubic feet. The only unit worth comparing prices on.
- Face cord, rick, or rank. A stack 4 feet high by 8 feet long by one log length deep. With 16 inch logs that is a third of a cord; with 12 inch logs, a quarter. The seller decides the depth, so ask.
- Truckload. Whatever the seller says it is. A half ton pickup heaped high holds roughly half a cord loose, often less.
Checking a Delivery
- Ask before ordering whether the price is per full cord, and what the log length is.
- Ask when the wood was cut and split. Seasoned should mean stacked for at least one full summer.
- Stack it before paying in full if that was agreed. A loose pile takes up about 180 cubic feet per real cord, so measuring a heap is a guess.
- Split three or four random pieces and meter the fresh faces. Highest reading under 20 means you got what you paid for.
- Look at the ends. Dark, checked, grey ends mean age. Bright, cream colored ends with no cracks mean a recent split.
Reputable sellers will not mind these questions. Vague answers about log length or cut date tell you enough.
A Note on Beetle Kill Pine
Much of the affordable firewood along the Front Range is beetle kill lodgepole or ponderosa. Our best firewood for Colorado guide covers why dry pine is a normal fuel here and why standing dead is not the same as seasoned. For the purposes of this article, treat it like any other wood: it often arrives partly dry, so the wait is shorter, but split it, stack it, and meter a fresh face before you trust it. Because pine throws more sparks, check that your cap has a working spark arrestor.
Free Field Tests Without a Meter
A meter is cheap, but you can get close without one. Use at least two of these together, because each alone can lie.
Sound
Knock two splits together. Dry wood rings with a hollow, almost musical clack. Wet wood thuds. Quickest test, least reliable alone, because surface dry wood also rings.
Checks in the End Grain
As wood dries it shrinks and the end grain opens into radial cracks called checks. Deep, dark, numerous checks mean long drying. Smooth, tight ends mean the opposite. Softwoods check quickly, so trust this less on pine than on oak.
Weight
Half the weight of a green log is water, so a seasoned piece feels noticeably light for its size. After a season of handling wood, most people can sort a pile by hand within a few points of a meter.
The Burn Test
Put a single split on a hot bed of coals. Dry wood catches within a minute and burns bright. Wet wood hisses, bubbles from the ends, blackens, and smolders. Steam pushing out of the end grain means the rest of that stack is not ready.
Frequently Asked Questions
What moisture content should firewood be before burning?
Twenty percent or less, measured on a freshly split face at room temperature. Wood in the low 20s burns but smokes more and leaves more creosote. Above 30 percent it goes back on the stack.
How long does firewood need to season in Colorado?
Pine and aspen split in spring are usually ready by fall, six to ten months. Cottonwood and ash want a full year. Oak needs two summers. Split size, sun, and wind move those numbers in both directions.
Is it safe to store firewood in the garage?
We advise against it. Attached garages have poor airflow, so wood dries slowly, and insects in the bark wake up in the warmth and find their way inside. Store it outdoors and bring in a day or two of wood at a time.
When is the best time to buy firewood in Colorado?
Spring or early summer, so the wood gets a full season of sun and wind before you need it. Wood bought green in October cannot season in cold, short days and burns wet all winter. If you must buy in fall, buy wood sold as seasoned and meter a few fresh splits before paying.
How big is a cord and what is a face cord?
A full cord is 4 by 4 by 8 feet stacked, 128 cubic feet. A face cord or rick is 4 by 8 feet by one log length deep, a third of a cord with 16 inch logs and less with shorter logs. Compare prices only on the full cord.
Should I cover my woodpile with a tarp?
Cover the top only. A tarp wrapped around the whole stack traps moisture and blocks the wind that does the drying. Leave the sides and ends open and weight the cover so Front Range gusts do not carry it off.
How can I tell if firewood is dry without a meter?
Use several tests together. Dry wood rings when knocked, feels light for its size, shows deep checks in the end grain, and catches quickly on coals without hissing. A meter on a fresh split is still the only test that gives you a number.
Next Step: Burn Dry, Then Let Us Check the Flue
Build the stack this spring, test a fresh split before the first cold night, and keep the top covered through monsoon season and snow. Once the wood is dry, build fires top down so the flue warms fast, as our guide to getting more heat from your fireplace explains, and follow our ash disposal guide, since ash can hold live coals for days. Less creosote also means a better chance your chimney inspection ends with a clean bill.
If you have been burning questionable wood for a season or two, the creosote is already there and a change in fuel will not remove it. Schedule a chimney sweep and cleaning before heavy use begins. Current rates are on our pricing page, and you can reach the crew at Adam Chimney Sweep at (720) 207-9232 or through our contact page. We are happy to look at your woodpile while we are there and tell you honestly whether it is ready.
