Even 'backwoodsmen' need a refresher on wood-stove safety

Even in timber country, it seems, people feel the need to know more - often a lot more - about heating with wood. So when George Jones threw open his stove shop for a wood-burning workshop here recently, the folks trooped in despite lingering summer temperatures.

They learned a lot. But more than anything else they learned this: ''Stoves seldom make (wood-burning) problems; people do.'' It was a message every speaker , from chimney sweep to fire marshal and insurance assessor, emphasized. Stoves don't make creosote, and they almost never cause house fires. Human mismanagement is the overwhelming culprit.

Until the turn of the century people grew up with the woodman's ax and garden-length stacks of cordwood. They learned from observation what to do and what not to do with a wood fire.

In an age of oil, gas, and electric heating units, more recent generations only learned how to adjust a thermostat. So when the decade-long rush back to wood heat began, many people lacked even the basic understanding required for this new-old technology. Many discovered that grandpa had to know a whole lot more than they believed, despite the ''simpler age'' in which he grew up.

Even so, the technology is uncomplicated and the rules governing its safety and efficiency relatively straightforward. They can be readily mastered and ''economic, worry-free comfort can be yours,'' as the meeting brought out. It is a theme echoed by others who have successfully returned to heating - and sometimes even cooking - with wood.

Four basic rules govern safe heating with wood. They are: Get the right-size stove for your needs (better too small than too large), install it correctly, operate it properly, and maintain it conscientiously. How do we do this and why is stove size so important?

The stove. Don't buy too big for your needs. Oversize stoves quickly overheat the house and people naturally respond by closing the damper, often to a mere crack. This brings down the heat but creates a smoldering, inefficient, creosote-producing fire. With a slow fire, more gases escape unburned to condense on the chimney walls as creosote.

In contrast, the right-size stove needs to be dampened only moderately. With adequate oxygen, the fire burns efficiently, and fewer unburned gases leave the stove. Those that do are often expelled from the chimney because of the greater draft from a more vigorous fire. In addition, the faster, more efficient burn rate means more value for your fuel dollars.

It goes without saying that the stove should not have any large cracks that might make it dangerous to operate. You would be wise, too, to buy a ''listed'' stove, that is, one that has met the approval of a recognized testing laboratory. Underwriters Laboratories (UL) is one of the more recognized of these companies.

Correct placement. Stand the stove on a noncombustible floor (stone or brick) or place it on an approved floor protector. Believe it or not, people have been known to install stoves directly over deep-pile carpeting. Have the floor protector extend 6 inches out from the back and sides of the stove and 18 or more inches beyond the side where the stove door opens.

The stove must also be at least 36 inches - and the stovepipe to the chimney 18 inches - away from any combustible surface, including furniture. Or place a metal screen between the two. The screen must stand at least one inch clear of the surface that it's protecting so that cooling air can circulate freely behind it. Since smoke rises, always have the pipe enter the chimney at a point higher than the outlet to the stove firebox.

Stove operation. To keep a chimney relatively clean, start the stove each day with a good brisk burn. Open the damper wide and ''let the fire roar'' for 15 minutes or longer, the meeting was told. The effect of this is to blow much of the accumulated soot out of the chimney.

If you've been out and left the stove on a slow burn all day long, open the damper wide for another 15 minutes the moment you get in.

These short, self-cleaning operations can do a lot to keep down the soot-creosote accumulation. One person at the workshop cited his own experience. He said he burned 10 cords of wood a year, but because he ''let the fire go'' several times each day, only half a pail of soot was removed from the chimney when it was swept this summer - for the first time in three years!

Maintenance. Stove maintenance means a good deal more than simply removing the ash every few days. It also means sweeping the chimney at least once a season and checking on the stovepipe once every week. Do this by tapping lightly on the pipe with a small stick or even the poker. You will soon detect if creosote is building up on the inside by the more dull sound that is produced. At that stage, remove the pipe and clean out the creosote.

Never try to force an oversize log into the firebox. Cutting a piece off the end of the log can be a time-consuming irritation, but it's better than cracking the stove.

Maintenance also means checking on the chimney.

Ideally you should have a chimney that is tile-lined or else one that has been lined or relined with a poured refractory-cement flue (Permaflu and Supaflu are two brand names).

A good way to check on the tightness of your chimney is to block off the top with a piece of board and then place a smoke bomb through the clean-out door at the bottom of the chimney. Lacking the usual easy way out at the top, the smoke will seek to exit wherever it can. If smoke begins to seep through the walls of the chimney, that proves that at least one crack exists. Fix it before you hook up the stove.

One final way to reduce creosote formation in your chimney is to insulate it wherever it is surrounded by cold air, as in an unheated attic or when it runs up the outside wall of the house.

There are several books on the market dealing with wood-fire safety. A particularly good one, in my estimation, is ''Wood Heat Safety'' (Gardenway Publishing, Charlotte, Vt. 05445), by Jay W. Shelton, a former physics professor at Williams College, Williamstown, Mass., and a recognized expert in the wood-heat field.