Burning Redwood Lumber & Firewood (BTU & Safety
Clean, dry redwood can be burned in a listed wood-burning appliance, but it gives about 20 million Btu per full cord as a planning estimate, often less heat per stacked volume than denser hardwoods. Burn only untreated wood at 20% moisture or less. Keep appliance clearances, chimney condition, and saw procedures in line with their manuals and applicable codes.
Redwood can be useful fuel when it is clean, dry, and already on hand. For a winter woodlot, value for money depends on more than the species name: moisture, cord volume, transport, and appliance efficiency all affect the heat you get. A wet or loosely piled load can make a promising price poor value.
The biggest safety distinction is between firewood and lumber. Sound, untreated redwood may be suitable to burn. Lumber that is painted, stained, pressure-treated, glued, coated, or of unknown history is not. Burning it can release hazardous fumes and leave contaminated ash. This guide covers how to identify suitable material, prepare and measure it, and burn it with care.
Redwood Heat Value and What a Cord Means
Redwood’s heat value is an estimate of the energy in a measured amount of wood. A full cord is 128 cubic feet of stacked wood, nominally a 4-by-4-by-8-foot stack. The estimate is useful for planning, not a promise of heat from a particular load or stove.
A practical planning figure for redwood firewood is roughly 20 million Btu per full cord. Actual usable heat varies with moisture, species, piece size, and appliance efficiency. Redwood is relatively light compared with many dense hardwoods, so a cord may deliver less heat per volume than a cord of a denser species. It can still be worthwhile when it is local, inexpensive, and properly seasoned.
Do not compare a full cord with a loose pile by appearance alone. Wood stacked with large gaps, short rows, or mixed lengths may contain less wood than its outer dimensions suggest. Confirm that a seller’s stated quantity is stacked volume, and ask how the measurement was made.
| Material or measure | Practical meaning | What to check |
|---|---|---|
| Redwood firewood | About 20 million Btu per full cord as a planning estimate | Moisture, soundness, and species |
| Full cord | 128 cubic feet stacked | Stack dimensions and gaps |
| Moisture target | 20% or less | Meter reading on a freshly split face |
| Lumber | May have coatings or treatments | Burn only if known to be clean and untreated |
The cord figure is not an appliance output rating. Your stove or fireplace delivers only part of the wood’s energy as useful room heat. Follow the appliance instructions and use measured wood volume when comparing fuel costs.
Identify Redwood and Check Moisture
Moisture content is the amount of water in wood compared with its dry mass. For firewood, aim for 20% or less, measured on a newly exposed split face. A dry-looking outside surface does not prove the center is ready to burn.
Redwood may come as rounds, split firewood, or construction lumber. Appearance alone cannot establish whether lumber is safe: coatings and treatments may be hard to see, and old boards may have an unknown history. If you cannot verify that a piece is untreated and clean, do not burn it.
For a moisture check, split a representative piece and press the meter’s pins into the fresh interior according to the meter instructions. Check more than one piece from the stack, including thicker splits. Record the readings and date; this gives you a better picture than one reading from a dry end or sunlit surface.
| Check | Good practice | Why it matters |
|---|---|---|
| Meter location | Freshly split interior face | The outer surface can dry before the center |
| Sample size | Several representative pieces | One piece may not reflect the whole stack |
| Target | 20% moisture or less | Helps support cleaner, more effective burning |
| Drying setup | Cover the top; leave sides open for airflow | Rain protection and airflow support drying |
Drying time is not a fixed number of months. It depends on the starting moisture, split size, weather, airflow, and how the wood is stacked. Split oversized rounds, stack wood off the ground, and leave space for air to move through the pile. Measure before burning rather than relying on a calendar.
Equipment Setup and Safety Preparation
Preparation means checking both the wood-burning setup and any tools used to make firewood. The appliance manual sets operating instructions and listed clearances; the chainsaw manual sets saw-specific limits. Do not replace either source with a general rule when the exact model requirements are available.
Before using the appliance, check its condition and chimney, confirm smoke and carbon monoxide alarms work, and keep nearby items beyond the appliance’s listed clearances. If you cannot find the listing or manual, do not guess at a clearance. Have the setup assessed under applicable rules; NFPA 211 is a relevant installation standard.
Before cutting, wear a helmet with eye and face protection, hearing protection, chainsaw-rated leg protection, gloves, and boots. Inspect the saw, chain brake, chain tension, and bar. Clear the work area and an escape path. Do not cut overhead or beyond your training.
For saw fuel, chain and bar fit, and idle or full-throttle speed, use the exact operator manual for that model. There is no safe universal fuel ratio or RPM that applies to every chainsaw. Keep the woodpile and kindling away from the appliance and other ignition sources.
Field Cutting and Firewood-Burning Operation
Safe operation means using suitable wood and controlling each step, from cutting to feeding the fire. Start and cut the saw as its manual directs, stand on stable footing, and keep a controlled work position. Stop if the wood, footing, or cutting angle makes the task unsafe.
Cut only sound, known, untreated wood. Split large rounds so they dry more evenly and are manageable for your appliance. Keep the pile covered on top, with open sides for airflow, and check the interior moisture before use. Never burn wet wood to try to dry it in the appliance.
Build a small, hot fire with adequate air, and operate the appliance as listed. Use only dry wood and supervise the fire. Keep children, pets, and combustible items clear. Do not use gasoline or other liquid accelerants.
The following are illustrative decisions, not reports of specific installations:
- Clean, dry firewood: A split reads 18% on the meter, and its history is known. It meets the moisture target; burn it only in an appliance suited to wood and operated by its manual.
- Unknown board from a remodel: It looks like redwood, but its coating or treatment is uncertain. Do not burn it. A species guess cannot confirm that lumber is clean.
- Thick round that reads high inside: The outside seems dry, but a fresh split face reads above 20%. Split it smaller, restack it with airflow, and test again later.
These checks help avoid spending time and fuel on material that is unsafe or not ready. A meter reading and known wood history are more useful than color, touch, or a drying-time guess.
Maintenance, Inspection, and Sharpening
Maintenance keeps the saw and heating system in safe working order. Inspection does not make an unsafe tool or damaged appliance safe to use; it helps you notice problems before work begins. Follow each manufacturer’s schedule and instructions, and use a qualified professional where a repair or chimney assessment is needed.
Before cutting, check the saw’s chain tension, bar condition, chain brake, and general condition. Do not force a dull or loose chain through wood, and never defeat the chain brake. After cutting, stop the saw, let it cool, clean it, and inspect the chain and bar again.
For the appliance and chimney, follow the manual’s inspection and cleaning guidance. Stop using the system and seek qualified help if you find damage or suspect a chimney problem. The moisture target reduces one important risk, but it does not replace routine chimney care or safe operation.
Safe Shutdown, Ash Handling, and Seasonal Storage
Safe shutdown includes letting the fire die down without adding accelerants and handling ash only after it is fully cold. Ash can retain heat after it looks inactive, so do not treat a cooling bed as ready for disposal. Use a covered metal container outdoors on a noncombustible surface.
After cutting, stop the saw and allow it to cool before cleaning or storage. Inspect the bar and chain, and store the saw as its manual directs. Keep fuel and wood away from heat sources, and maintain safe separation between the woodpile and the appliance.
Before the next heating season, check the appliance, chimney, alarms, and stored firewood. Recheck moisture on freshly split faces rather than assuming a stack stayed dry under cover. If rain reached the pile or readings remain above 20%, give the wood more drying time.
Frequently Asked Questions
These answers cover the common decisions behind redwood firewood: heat value, measurement, moisture, lumber safety, and appliance use. They are general guidance, not a replacement for your stove or chainsaw manual, local requirements, or a qualified inspection of a questionable installation.
How much heat does a cord of redwood provide?
Use about 20 million Btu per full cord as a planning estimate. Actual useful heat depends on moisture, species, piece size, and appliance efficiency.
What counts as a full cord?
A full cord is 128 cubic feet of stacked wood, nominally a 4-by-4-by-8-foot stack. A loose pile is not the same measurement.
Can I burn redwood lumber?
Only if you know it is clean and untreated. Do not burn lumber that is pressure-treated, painted, stained, glued, coated, or of unknown history.
What moisture reading should I aim for?
Aim for 20% moisture or less. Check the freshly split interior face, following the meter instructions.
Can I tell that firewood is dry by looking at it?
Not reliably. A dry exterior can hide a wetter center. Split a piece and use a moisture meter.
How long does redwood take to dry?
There is no dependable fixed schedule. Drying time varies with starting moisture, split size, weather, airflow, and stacking. Measure the wood before burning.
Is redwood as hot as dense hardwood?
Redwood can be useful fuel, but it generally provides less heat per stacked volume than denser hardwoods. The planning estimate is not a direct comparison of every species or appliance.
Can I burn wood above 20% moisture to dry it in the stove?
No. Dry the wood outdoors with airflow and check it again before use. Do not use the appliance as a wood dryer.
What clearance should I leave around a wood stove?
Use the clearance listed for that appliance and follow its manual. If the listing or manual is unavailable, do not assume a generic distance; have the installation assessed under applicable rules.
Is there a standard chainsaw fuel mix or RPM for cutting redwood?
No universal value applies to every saw. Use the exact fuel ratio, chain and bar specifications, and speed limits in the model’s operator manual.
(This article was written by one of our staff writers, Samuel Vance. Visit our Meet the Team page.)
