Best Firewood for a Fireplace: A Sweep's Guide to Species & Seasoning

Half the "smoky fireplace" and "creosote problem" calls we take every winter come down to one thing: wet or wrong wood. Here's the sweep's take on what to burn, what to season, and what to leave in the yard.

The one number that matters: moisture content

Everything else is secondary to moisture. Firewood should read 15–20% moisture on a pin-type meter (about $25 at any hardware store). Above 25% and you're paying to boil water; below 12% and it burns too fast.

Fresh-cut ("green") wood is 40–60% moisture. Seasoning removes that water. There is no shortcut — no matter what the species.

The A-list: dense hardwoods

These are what you actually want in the stack. High BTU per cord, long clean burns, low creosote.

• Oak — 24–28 million BTU/cord. Seasons in 18–24 months. The gold standard.
• Hickory — 27–28 million BTU. 12–18 months. Best coal bed on this list.
• Sugar maple — 24 million BTU. 12 months. Clean and easy to split.
• Ash — 20–24 million BTU. 6–12 months (the only major hardwood you can burn same-year). Emerald ash borer means lots of ash on the market — take advantage.
• Beech, black locust, apple, cherry — all excellent, similar BTU range.

The B-list: acceptable but manage your expectations

• Birch — 20 million BTU. Burns fast. Great starter wood; not a primary.
• Red maple, elm — 18–22 million BTU. Hard to split (elm is famously stringy).

The C-list: use with care

• Pine, fir, spruce, cedar — 12–16 million BTU. Burns hot and fast, deposits more creosote than any hardwood. Fine for outdoor fires and kindling. Indoors, only in short bursts and with more frequent sweeping (every 1/2 cord).

Never burn indoors

• Pressure-treated lumber — arsenic and copper release toxic fumes
• Painted or stained wood — VOCs, lead risk on older paint
• Plywood, MDF, particleboard — formaldehyde
• Driftwood — salt corrodes metal chimney components rapidly
• Wet or moldy wood — creates more smoke than heat, deposits massive creosote
• Poison ivy, oak, or sumac — the smoke carries the toxic oil

Seasoning done right

• Split before stacking — round logs season 3x slower
• Stack off the ground — pallets or rails
• Top-covered, sides open — tarp only the top 6 inches, let wind through the sides
• South-facing sunny spot if possible
• Check moisture at 6 months, 12 months, and before burn — one meter, freshly split face, three readings averaged

The burn-day habit

Cold flue + wet wood = the smoke problem we get called about most. Prime the flue, use dry kindling, and load the primary logs only after the flue is warm. That single change eliminates 90% of "my chimney doesn't draft right" complaints.