"For Heat and Safety, Choose Well-seasoned Hardwood." But what type? And how do you know what you're getting, if you buy wood? What should you look for, and what should you look out for?

 

 

 

 

 

There are several considerations: The species and density of wood that produces the best heat, the wood's dryness or seasoning time when it is burned, the amount of sap or resin released during burning that produces sparks and contributes to creosote, and if you buy wood, how you can evaluate and verify what you're getting.

Sources for the following information about locally available wood types include: "Firewood in Pacific Northwest Forests," published by the U.S.D.A. Forest Service, "Burn Wood Better," published by the Oregon DEQ (Dept. of Environmental Quality) Air Quality Division, and an article from the Siskiyou Daily News submitted by local resident Maurine Lockwood, entitled, "For heat, you just can't beat a stack of oak," page 12, Fall Home Improvement Section, Thursday, October 7th, 1999.

 

Ratings of Different Firewoods
Species	Heating Quality	Ease of Splitting	Ease of Starting	Sparks
Alder	Medium	Easy	Fair	Moderate
Apple	Medium-High	Difficult	Difficult	Few
Ash	High	Easy-Moderate	Fair-Difficult	Few
Aspen	Low	Easy	Easy	Few
Beech	High	Difficult	Difficult	Few
Birch, white	Medium	Easy-Moderate	Easy	Moderate
Cedar, Western Red	Medium-Low	Easy	Easy	Many
Cedar, Incense	Medium-Low	Easy	Easy	Many
Cherry	Medium	Easy	Difficult	Few
Cottonwood	Low	Easy	Easy	Moderate
Dogwood	High	Difficult	Easy	Few
Elm	Medium	Very Difficult	Fair	Very Few
Fir, Douglas	Medium	Easy	Easy	Moderate
Fir, Grand	Medium-Low	Easy	Easy	Moderate
Fir, Noble	Medium-Low	Easy	Easy	Moderate
Fir, Pacific Silver	Medium-Low	Easy	Easy	Moderate
Fir, White	Medium-Low	Easy	Easy	Moderate
Hemlock	Medium-Low	Easy	Easy	Many
Hickory	Very High	Moderate	Fair-Difficult	Moderate
Ironwood (Hornbeam)	Very High	Very Difficult	Very Difficult	Few
Juniper	Medium	Difficult	Fair	Many
Larch (tamarack)	Medium-High	Easy-Moderate	Easy-Fair	Many
Larch, western	High-Medium	Easy-Moderate	Easy	Many
Locust, black	Very High	Very Difficult	Difficult	Very Few
Madrone	High	Difficult	Difficult	Very Few
Maples, red & sugar	High-Medium	Moderate	Fair-Difficult	Few
Mesquite	Very High	Very Difficult	Very Difficult	Few
Mulberry	Medium	-	-	-
Oak, black	High	Moderate	Difficult	Few
Oak, white	Very High	Moderate	Difficult	Few
Pine, lodgepole	Low	Easy	Easy	Moderate
Pine, ponderosa	Medium-Low	Easy	Easy	Moderate
Pine, white	Medium-Low	Easy	Easy	Moderate
Pine, yellow	Medium-High	Easy	Easy	Moderate
Poplar	Low	Easy	Easy	Moderate
Redwood	Medium	Easy	Easy-Fair	Many
Spruce, engleman	Low	Easy	Easy	Few
Spruce	Low	Easy-Moderate	Easy	Few
Sycamore	Medium	Very Difficult	Fair	Few
Walnut	High-Medium	Easy-Moderate	Fair	Few
Willow	Low	Easy	Fair	Moderate

Hardwoods like oak and madrone are the heaviest firewoods, with the most BTUs locked in the dense, tight grain. They burn longer and more evenly than softwoods.

Fuel Values of Some Common Woods
Wood Type (Assuming 20% Moisture Level)	Average Density (lbs. per cord)	Fuel Value per cord in BTUs (British Thermal Units)
Shagbark Hickory	4400	30.8 million
White Oak	4400	30.8
Madrone	-	30.0
Sugar Maple	4100	29.7
American Beech	4000	28.0
White Ash	3700	25.9
American Elm	3400	23.8
Douglas Fir	2900	21.4
Cedar, Incense	-	17.5
Ponderosa Pine	-	17.0
Eastern White Pine	2200	15.8

You can save money if you have the wood dumped, and stack it yourself. However, one way to know if you're getting a full load is to have the wood supplier stack the wood (a typical cost is $5 to $10 per face cord). Mark off an area in 4-foot-by-8-foot increments to be filled, making sure not too much airspace is left in a criss-cross wood stacking pattern.

Quality: Green, unseasoned wood can often be detected by its fresh tree fragrance. Split and dried wood that has seasoned at least 6 months should have splits or cracks at the end of the log. Another way to identify cured wood is when the bark peels off easily. Older wood is also greyish or greyer in color. The best way to ensure seasoned wood is to either buy it or cut it a year ahead of when you'll need to use it, to give it time to thoroughly dry.

The Chimney Safety Institute of America suggests that if the "seasoned" wood you bought turned out to be green and you need to burn it anyway, be sure to have your chimney or stovepipe checked often, and cleaned if necessary, to prevent creosote buildup.

There is another way to verify seasoned firewood: You can ask a firewood supplier to have the load checked and certified for its wood moisture percentage. This service is available to both buyers and sellers, free of charge at some locations within the Rogue Valley. Check with Jackson County services for current certification sites.

Type: If you buy mixed local hardwood from a tree service, it may not be as seasoned. But wood that comes from logging mills is often of premier, uniformly sized quality, and has usually been cut or fallen down longer, maybe for a year, which allows the sap to drain out and the wood to dry before splitting.

Stay away from Cottonwood, willow and osage orange softwoods, because of the odor and smoke potential. Highly resinous types such as pine and manzanita spit sparks, and should be limited to use as starter fuel, or mixed with hardwoods.

Softwoods such as Birch can be good, fast-burning types that produce a lot of flame, but go quickly and with less heat value, while seasoned hickory burns slowly and gives off heat, but smells up the house. Oak is the best choice for the hottest, cleanest-burning wood.

Purchase prices: Since hardwoods grow more slowly, they are inevitably more expensive. Fruit woods, valued for their aromatic qualities, are also more costly. An average price for a cord of hardwood is now about $145, not including possible additional delivery costs.

Dryness: The more seasoned wood is, the more it maximizes heat yield.

Well-seasoned (dried) hardwoods provide more usable BTUs than green (wet) wood, which uses heat energy to change excess moisture into steam.

Seasoned softwoods start and burn more easily and burn faster, but do not give off as much heat as hardwoods like oak.

Underseasoned wood can hold about twice the water content of seasoned wood, and is hard to ignite, and will produce more sparks than if dry.

Wood has a low ash content. When dry (thoroughly cured), it burns cleanly and efficiently, leaving a minimum amount of ash as waste. Wet wood is the worst polluter. Wet wood is also a leading cause of creosote buildup.

The minimum outdoor drying time, split and covered, for all wood is at least six months, or for a full summer. Some woods, such as alder, require longer than this. Splitting logs hastens drying.

Storage: Season split wood by raising it off the ground and covering it. Stack split or small round logs to allow air circulation and leave under cover for a year, if possible, preferably where it is exposed to sun. Protecting it from rain or snow keeps moisture from seeping dampness back into the wood, and rotting it over time.

It isn't necessary to store wood in a garage, because a simple covering will suffice. The idea is to keep moisture off the wood while drying. Keeping firewood inside or next to the house for more than a week can also create a termite problem. Also, wood stacked next to or just below the house contributes to wildfire fuel hazards during fire season.

 

• Weatherize: Conservation is the cheapest way to cut heating costs.
  
  
• All stoves sold in Oregon after 1986 have been required by law to be certified as "clean burning" stoves. (This was to cut smoke emissions). Clean-burning stoves, catalytic or not, burn more completely, with less creosote buildup, and are safer. For more information on certified stoves, contact the Oregon DEQ at (503) 229-6488 or 1-800-452-4011.
  
  
• Buy the right sized stove: A stove too large for the area you want to heat must be dampered down, creating smoke, reducing efficiency and creating creosote buildup.
  
  
• Never burn garbage, waxed paper, plastic or treated wood, or chemically treated wood such as discarded railroad ties, utility poles, and many yard fences or other previously painted or treated wood, as they can release poisonous or toxic fumes, and could add to those materials that collect in the chimney, increasing the possibility of fire.
  
  
• When using a fireplace gas igniter, leave space between logs, so the wood can ignite. Otherwise the gas will just hover around the logs.
  
  
• When starting a fireplace fire with a traditional log pyramid, keep it small. Logs eventually collapse and can shoot hot cinders and sparks.
  
  
• Build small fires, burn hot and restoke: Small fires with plenty of oxygen burn cleanest. Burn briskly the first 30 minutes after loading, then keep fire at a moderate burn rate.
  
  
• Check your stack and clean your chimney: Go outside and look at smoke against a dark background, if possible. The less smoke coming out of your stack, the cleaner you're burning. Keeping your chimney clean helps increase efficiency and safety.