Tamarack Firewood Heat Output (BTU Chart)

Tamarack, usually eastern larch, has a planning value of about 20.8 million BTU per standard cord of seasoned wood. A cord holds 128 cubic feet when stacked. Treat that figure as an estimate, not guaranteed heat: moisture, stove efficiency, and firing conditions change what reaches your home. For routine burning, check a freshly split face and aim for 20% moisture or less.

Tamarack can be a useful heating wood, but a BTU number alone will not tell you how warm a load will burn. The cord measurement, wood moisture, and your stove all matter. In woodlot work, I see two common sources of confusion: comparing figures built on different measurement bases, and trusting a moisture reading taken from the outside of a round.

The practical goal is to identify the wood, measure it correctly, and process it so it dries well. The chart and field steps below help you estimate heat without treating a published value as a promise.

Tamarack Heat Output, Cord Basis, and Moisture

This section explains what the usual heat figure means and how to use it. Tamarack is commonly used for eastern larch, or Larix laricina. Its estimated heat output is about 20.8 million BTU per standard cord of seasoned wood, but that value is useful only when you understand the cord size and moisture basis behind it.

What the BTU chart value means

A British thermal unit, or BTU, is a measure of heat energy. A chart value estimates the energy in a volume of wood; it does not state how much heat your stove will deliver to the room. Stove efficiency, draft, load size, and operating practice affect useful heat.

The cord includes the spaces between pieces. The amount of solid wood in a cord varies with piece size and how the stack is arranged, so a cord is a volume measure, not a fixed weight. A face cord is a stack one row deep, but its depth and total volume vary. Ask for dimensions before comparing its price or heat value with a full cord.

Published BTU charts can differ because species labels, density, and moisture assumptions may differ. Some charts may also report heat on a different volume basis. Compare tamarack with another species only when the cord definition and moisture basis are alike. Otherwise, the comparison can make one wood look better simply because the measurements differ.

How moisture changes usable heat

Moisture content describes the water held in the wood, usually as a percentage of the wood’s dry weight. Water in a log takes heat to warm and evaporate during burning. Wet wood can therefore provide less useful heat and create more smoke, raising creosote concerns when combustion and chimney conditions allow deposits to form.

For routine firewood use, aim for 20% moisture or less. Split a sample piece and press the meter’s pins into the fresh interior face, following the meter maker’s instructions. Do not rely on a reading from bark or an old, weathered surface. Take readings from several pieces in the stack, since one dry stick does not prove the whole load is ready.

If readings remain high, keep the wood split and stacked with airflow, then measure again. Drying time varies with climate, sun, wind, stack position, and piece size. A calendar estimate cannot replace a meter reading.

Chainsaw Setup and Safety Preparation

Before cutting tamarack, prepare the saw for its specific model and attachment. No bar length, chain fit, fuel ratio, or engine-speed setting applies to every chainsaw. Use the operator’s manual and the cutting attachment instructions, then inspect the saw and work area before starting.

Match the saw to its manuals

Check the saw’s manual for approved bar length, chain pitch, gauge, and drive-link count. These details must match the bar and chain. Follow the specified raker setting, bar-oil type and flow checks, and idle and wide-open-throttle RPM limits. Do not infer a setting from the fact that tamarack is the wood being cut.

Use the exact fuel mix listed by the saw maker. A 50:1 mix is common, but it is not universal. Never run a two-stroke saw on straight gasoline. If the manual is missing, identify the model and obtain the correct instructions from the manufacturer before choosing parts, fuel mix, or settings.

Inspect PPE and the work area

Wear a helmet with eye and ear protection, chainsaw chaps, gloves, and sturdy boots. Before starting, check that the chain brake, throttle lockout, chain catcher, controls, chain tension, and chain sharpness are in good condition. Confirm that the bar is lubricated as directed.

Clear brush and loose objects from the cutting area. Plan an escape path and keep bystanders well away. Stabilize the log before cutting, and do not operate the saw if it leaks, vibrates abnormally, or fails an inspection. Follow applicable workplace rules, including OSHA 29 CFR 1910.266 where they apply.

Field Bucking, Splitting, and Seasoning

Bucking means cutting a log into stove-length pieces; splitting opens those pieces so they dry faster. Tamarack heat estimates assume seasoned wood, so processing matters as much as species identification. Work safely, make pieces suited to your stove, and leave enough space around the stack for air to move.

Buck and split with control

Start the saw on stable ground with the chain brake engaged, following the manual’s cold- or warm-start steps. Check for chain-oil delivery and watch for leaks or unusual vibration. If the saw does not pass these checks, shut it down and fix the problem before cutting.

For each cut, assess how the log is supported and where it is under tension or compression. A cut can pinch the bar or cause a log to roll if the support is unstable. Keep secure footing, use two hands, and keep the guide-bar nose clear of the ground and nearby objects. Do not cut above shoulder height.

Rotational kickback can happen when the upper part of the guide-bar nose hits wood or another object. The bar can then move rapidly back toward the operator. Keep the nose clear, use the chain brake and low-kickback equipment where specified, and never use the bar tip on purpose.

After bucking, split rounds to a size that fits your stove and allows the stack to dry. Smaller pieces have more exposed surface relative to their volume, which helps moisture escape, though actual drying still depends on weather and airflow. Stack wood off the ground, with open sides or gaps that let air pass through. Avoid tightly packing the pile.

A yard scenario shows why measurement beats a fixed drying claim: if one stack sits in sun and wind while another stays shaded and sheltered, they may not reach the same moisture level at the same time. Check each stack with a meter rather than assuming they are ready together.

Verify readiness before burning

Measure several split pieces from different parts of the stack. Split each sample again if needed, then take the reading on the newly exposed interior face. Follow the meter instructions for pin direction, temperature correction, and wood setting, if provided. A reading over 20% means the sample has not met the routine target.

Record the date, stack location, species, and readings. This simple log helps you see how your own yard and weather affect drying. It also helps prevent a common mistake: labeling a stack “seasoned” by age alone. Recheck readings near the time you plan to burn the wood.

Saw Maintenance, Storage, and Seasonal Care

Good care keeps the saw ready for the next round of cutting and helps prevent avoidable failures. Stop work before cleaning or refueling: engage the chain brake, shut off the engine, and let the saw cool. Follow the manual for cleaning, inspection, fuel storage, and seasonal storage.

After cutting, remove chips and inspect the bar and chain for wear or damage. Maintain chain sharpness and tension as directed; do not guess at adjustments. Check that the bar-oil system is working before the next job. Use only the bar oil and fuel handling steps approved by the manufacturer.

Store fuel and the saw as the manual directs, away from ignition sources and where children cannot reach them. Before returning to work, repeat the PPE, control, chain, and lubrication checks. A saw that sat through a season should not be assumed ready just because it ran well last year.

Takeaway: The tamarack figure of about 20.8 million BTU per cord is a planning estimate for a standard 128-cubic-foot cord of seasoned wood. Confirm moisture at 20% or less on a fresh split face, and use your saw’s manuals for every equipment setting.

Frequently Asked Questions

These answers cover the main decisions behind using tamarack for heat: what its chart value means, how to measure readiness, and how to compare or process a cord. Use the number as an estimate, then verify the wood and equipment in front of you.

How many BTU are in a cord of tamarack?
Use about 20.8 million BTU per standard cord as a planning estimate for seasoned tamarack. It is not a guarantee of heat delivered by a stove.

What is a standard cord of firewood?
A standard cord is 128 cubic feet of stacked wood, commonly arranged in a 4 × 4 × 8-foot stack.

Is a face cord the same as a full cord?
No. A face cord has no fixed equivalent because stack depth and piece size can vary. Confirm its dimensions before comparing it with a full cord.

What moisture level should tamarack firewood reach?
Aim for 20% moisture or less for routine firewood use. Measure the freshly split interior face, not the bark or outer surface.

Can I compare tamarack’s BTU value with another wood chart?
Yes, if the figures use comparable cord volumes and moisture assumptions. If those bases differ or are unknown, the comparison may mislead.

Does the 20.8-million-BTU estimate equal heat in my room?
No. It estimates fuel energy, not delivered room heat. Moisture, stove efficiency, and firing conditions affect how much heat is useful.

How long does tamarack take to season?
There is no reliable fixed time for every yard. Sun, wind, climate, stack design, and piece size all matter. Check moisture with a meter.

What fuel mix should I use in my chainsaw?
Use the ratio specified in that saw’s manual. Although 50:1 is common, it is not universal, and a two-stroke saw must not run on straight gasoline.

(This article was written by one of our staff writers, Samuel Vance. Visit our Meet the Team page.)