How to buy and store firewood

Seasoned, split firewood is a popular heating fuel in the Anza Valley. Anza Valley Outlook/Diane Sieker photo

Many people in the Anza Valley heat their homes with wood, a renewable biofuel that is plentiful and affordable.

Using wood as a main heating fuel means becoming familiar with heating properties, safe storage, volume measurements and safety.

The term BTU is used to describe the heating properties associated with different types of wood. BTU stands for British Thermal Unit, which is a traditional unit of measurement, defined as the amount of heat required to raise the temperature of one pound of water by one degree Fahrenheit. In wood burning, the BTU defines the amount of heat produced by a true cord of wood.

A cord is a unit of measurement of dry volume used to quantify firewood and pulpwood in the United States and Canada. The interesting name may have come from the use of a cord or string to measure it.

According to Wikipedia, “A cord is the amount of wood that, when ‘racked and well stowed’ (arranged so pieces are aligned, parallel, touching and compact), occupies a volume of 128 cubic feet (3.62 m3).”

As such, a tightly stacked woodpile measuring 4 feet high by 8 feet wide by 4 feet deep constitutes a cord. Any other arrangement of linear measurements that equal 128 cubic feet is also acceptable.

Sometimes wood shoppers see a cord advertised for a certain price, only to discover that they do not receive an actual cord of firewood. An average truck bed of wood does not represent an accurate cord, so buyers must understand this unit of measurement. The properly measured cord is also important in understanding the BTUs associated with the various woods offered for sale.

World Forest Industries offers a BTU table as a guide to the heating qualities of several different common species of trees.

Local western hardwood species, such as live oak, eucalyptus, manzanita and pepperwood are popular choices with high BTUs per cord.

Western softwood species, including Douglas fir, Western juniper, lodgepole pine and ponderosa pine are also popular, with slightly less BTUs per cord, due to a softer wood composition. More heat is produced with oak wood than pepperwood, by a large margin. Therefore a cord of oak is much more valuable than a cord of pepperwood.

Firewood needs to be dry before it is burned as a heating fuel. Advanced planning is best, as most people buy wood the year before it is needed, to ensure it is well seasoned and ready to burn efficiently.

Green, or freshly cut live wood, is a very poor fuel and very hard to get lit and burning, due to the high water content of the living wood.

Correct and safe storage is imperative. Keep wood off the ground, as it helps the wood continue to lose moisture. Space between logs that allows air flow and storing wood in an area that is exposed to sunlight and wind also helps dry it out. Southern California fire departments advised residents to store their wood piles at least 3 feet away from the home and other structures, in case of wildfire.

Cal Fire also recommended storing firewood away from live trees, to prevent the spread of pests or diseases that may be present in the imported wood. Many localities have laws regarding the importation of firewood from out of the area, so be sure to check the local guidelines.

Firewood should only be transported locally and within the same ecosystem.

Wood stoves are designed to burn wood, not trash or chemically treated wood products like building 2x4s. Using mostly hardwoods like oak and smaller amounts of softwoods like pine is best for the stove. Be sure to empty ashes frequently and safely, by using a metal fireplace shovel and putting ashes in a metal or other fireproof container in case there are hot coals still burning. Hot coals easily melt plastic buckets and can ignite a fire very quickly. Proper and safe disposal of the ashes can be made at home or at the Anza Transfer Station in a special metal dumpster provided for this purpose.

Have your chimney and pipes cleaned once a year by a professional licensed chimney sweep. An accumulation of tars and creosote can reduce efficiency or catch fire.

If you’re cutting your own firewood, be sure to wear protective gear, be familiar with chainsaw, ax and maul or wood splitter safety and learn safe methods to fell trees. Do not overload your truck or trailer with green wood, as it can be very heavy. Know your limits and that of your equipment.

Stay warm using this renewable biofuel, and by practicing proper safe storage and use techniques, stay comfortable and warm this winter.

To learn more about the effectiveness of wood as a biofuel, visit

Diane Sieker can be reached by email at