SO SANTA GOT your letter, and there, by the tree, sits your heart's desire: A bright, shiny, new wood stove.
Now it's time to give Santa something in return: A bright, shiny, new chimney.
Chimneys come in two types:
Double- or triple-walled "Class A" metal.
For a wood stove, you should seriously consider a metal chimney. They're fairly easy to install and relatively inexpensive. Masonry chimneys are beautiful, but they're expensive, and building one is far outside the skill level of the average homeowner.
Depending on how your stove is made, the stove pipe will exit from the top or the rear of the stove. Stove pipe is designed to connect a wood-burning stove to a nearby chimney -- and that's all. It cannot run through walls, floors, ceilings, or the roof.
In general, stove pipe must be kept 18 inches away from combustible walls, ceilings and furniture. (It is attached to a fitting that in turn connects to the chimney.)
The clearance can be reduced by protecting the wall or ceiling or by installing an approved heat shield on the pipe. In some cases, you might be able to reduce clearance to 9 inches, which could make installation a little less awkward.
Or you could use a double-walled stove pipe, which has a stainless steel liner (the air space between the pipe and the liner provides extra insulation), and reduce clearance to as little as 6 inches. The lined stove pipe is still stove pipe, and it can't go through combustible surfaces.
The Class A chimney can be run straight up through an attic or floor above, as long as the clearances designated by the manufacturer are maintained. They can also be run straight through an exterior wall and up the side of the house.
There are appropriate fittings to make all of the transitions through the roof, wall or floor above. If you mount the chimney to an outside wall, you can box it in and cover it with siding to match the house.
Just as you need to shop carefully to get a wood stove that matches your needs, you need to shop carefully to get the stove pipe and chimney components. Once you determine how the pipe and chimney will run, find a knowledgeable salesperson to help you get everything you need.
Here are some basic chimney rules, culled from experience and a bit of research:
The chimney should extend 2 feet higher than any part of the house that is within 10 feet of it, though the taller it is, the better. The 2-foot rule is a building code minimum; in practical terms, a higher roof 12 feet away can still interfere with the way the chimney draws. If a tall chimney seems unsightly, you might want to rethink the location of the stove.
Use only UL- (or other testing lab) approved Class A chimney. Make sure the testing lab is recognized by your local building inspections department.
Install the chimney with as few turns as possible. Turns reduce draft. The fire will burn best with a straight chimney.
Seal the chimney well if it runs through a roof or eave. Water leaking down the inside or outside of the chimney can damage interior walls or ceilings or increase creosote buildup in the chimney. Chimney kits come with appropriate flashing, but you may want to consult a roofer.
Always use a chimney cap to keep birds and other critters out of the chimney. Clean the chimney in the fall before the first fire in case something got inside over the summer.
Don't try to save money by reducing the size of the chimney. Use the chimney that is specified.
Next: Clearance around the stove and protection for your walls and floors.
Pub Date: 12/29/96