| Wood
stove safety
If your
among the thousands who have succumbed to the lure of the wood burning
stove, keep in mind that the return to the "good old days"
of wood stove heating can have some old-fashioned drawbacks.
Fire hazard is one of them.
The resurgence of the wood burner as a supplementary source of heat
has led to an alarming-and growing-number of fires traceable to
careless installation or misuse.
The purpose of this pamphlet is to help bridge a generation gap
in wood stove knowledge by providing some basic information on the
selection, installation, use and maintenance of solid fuel heating
equipment.
Here are some principal do's and don'ts:
DO- make
sure there is enough clearance between the stove and
Combustible materials, including floors, walls and ceilings.
DO- place the stove on a noncombustible, fire-resistant base.
DO- have a mason or other competent person inspect the chimney.
DO- burn only dry, well-seasoned wood.
DO- consider opening a window a crack for ventilation.
DO- dispose of ashes in a closed metal container outside the house.
DON'T-
extend the stove pipe through a wall or ceiling unless there
Is no possible alternative.
DON'T- connect a wood stove to a chimney serving another appliance
Burning other fuels.
DON'T- start a stove fire with flammable fluids, such as gasoline.
DON'T- burn trash in a stove; doing so can start a chimney fire.
DON'T- let a wood fire burn unattended or overnight.
DON'T- connect a wood stove to a fireplace chimney unless the
Fireplace has been sealed off.
Selecting
a stove
Be sure
your stove is made of sturdy, suitable material, such as cast iron
or steel. Look for stove listed by Underwriters Laboratories (UL)
or other recognized testing laboratories.
If you
purchase a used stove, check it carefully for cracks or other defects.
The legs, hinges, grates and draft louvers also should be checked
carefully.
If you
live in a mobile home, be sure your stove is of a type specifically
approved for use in such a dwelling.
Installation
Before
installing your stove, check with local authorities to be sure you
comply with local fire and building codes.
Think twice about where you'll put your stove. Usually a centralized
location is best if the stove is to be used as a heating device.
One
point to consider is that warmed air rises. If the stove is too
near a stairwell, you may lose much of your heat to the floor above.
If you
plan to use an existing chimney, both its location and the length
of its flue will be determining factors. Note these guidelines:
o The
horizontal section of the uninsulated stove pipe should not be more
than three quarters as long as that section of the flue above the
point at
which the pipe and the flue connect.
o National
Fire Protection Association (NFPA) standards call for a 36-
inch clearance between a room heater stove and any combustible wall
or ceiling surface. If the length of the horizontal portion of the
stove
pipe won't permit that much clearance, protect the combustible wall
with a panel of some protective material, such as a sheet of metal,
spaced at least one inch from the wall.
Careful attention to the floor mounting of your stove is essential.
To
Meet NFPA standards:
o Stoves having less than two inches of ventilated open space beneath
the
fire chamber or base of the unit should never be installed on
combustible material beneath them unless permitted by their listing.
o Stoves having legs or pedestals providing two to six inches of
ventilated
open space beneath the fire chamber or base may be installed on
combustible floors protected by four inches of hallow masonry, laid
to
provide air circulation, and covered with 24 gauge sheet metal unless
permitted by their listing.
o If there are more than six inches of ventilated open space beneath
the
fire chamber or base, a stove may be placed on a combustible floor
protected by a solid brick, concrete or stone masonry unit at least
two
inches thick. That unit should be covered by a sheet of 24 gauge
steel
unless permitted by the stove's listing.
o The floor protection should extend at least 18 inches on all sides
of the
stove.
Chimney
requirements
If you
use an existing fireplace chimney to vent your stove, it must be
sealed off below the stove pipe's point of entry to prevent toxic
gases from backing up into the room. This can be done by:
o Sealing
off the fireplace opening, or
o Sealing off the flue itself between the stove pipe connection
and the fireplace opening.
The
cross-section area of the chimney flue should be at least 25 percent
bigger than and not more than three times that of the stove pipe.
Avoid connecting more than one heating device to a single chimney
flue because flue gases and sparks may pass from one flue opening
into another and unsatisfactory operation may also result.
Be sure your chimney is in good condition and that it has a flue
lining. Check for missing flue tiles and cracked masonry. You may
want to have a chimney sweep check the chimney and a mason make
any repairs that may be needed.
With a masonry chimney, the stove pipe should be extended through
the chimney wall to its inner face, but not beyond. Use high-temperature
cement to fasten the pipe to the masonry.
If you have no suitable chimney or if you prefer not to close off
your fireplace, a factory-built chimney listed by a recognized testing
laboratory is a good solution. It should extend at least three feet
above the highest point where it passes through the roof of the
building and at least two feet higher than any portion of a building
within 10 feet.
Stove
pipe
The
stove pipe be of corrosion-resistant steel of suitable gauge. These
are the standards set by NFPA:
Galanized
Diameter of
Sheet metal stove pipe
Gauge no. in inches
26 less than 6
24 6 to 10
22 10 to
(but not including) 16
16 16
NFPA
standards also call for a stove pipe to have an internal cross-section
area not less than that of the stove's flue collar.
The pipe should be as straight and short as possible, with sections
properly secured. If it must have angles, limit them to one or,
at the most, two sweeping 90-degree elbows or the equivalent. The
horizontal portion of the pipe should rise not less than one-quarter
inch to the linear foot, to insure a good draft.
You should not pass a stove pipe through a combustible wall for
a hook-up with a chimney flue.
However, if there is no alternative, the stove pipe must be passed
through a thimble or collar. NFPA has set these standards:
-A ventilated type 24-gauge metal thimble must be at least 12 inches
la
larger in diameter than the stove pipe.(it can be by a local sheet
metal
company or tinsmith.)
-A metal or burned fire-clay thimble must be surrounded by no less
than
eight inches of brickwork or equivalent fire-resistant material.
-Otherwise, all combustible material must be cut out of the wall
to
provide at least 18 inches of clearance on all sides of the pipe.
Materials for closing this opening must be non-combustible and
Insulating.
Dampers
If a
wood burning stove has an automatic draft regulator controlled by
a thermostat, the manufacturer's instructions for installing it
must be carefully followed. Alternately, a manually operated damper
can be installed on the pipe near the stove. This damper should
not obstruct more than 80 percent of the pipe area.
A second damper higher up on the vertical section of the stove pipe
is advisable to permit shutting down the stove in case of a chimney
fire. You can have this made by a local sheet metal company or a
tinsmith.
Your
wood
Green
wood has to high a moisture content for satisfactory use. For your
stove select wood -preferably hard wood-that has been seasoned six
months to a year.
Wood split before storing to season dries in less time and burns
more evenly. Apple, red oak, sugar maple, beech and ironwood have
the best heat values, according to the University of Maine Extension
Service.
Use of the proper wood is your best safeguard agaisnt ana ccumulation
of creosote, an oily substance which derives from incomplete combustion,
on the lining of the chimney flue. A spark can ignite creosote and
cause what can be an extremely hot and dangerous fire.
Dry and well-seasoned wood will not only minimize the chance of
creosote formation, but will give you the most efficient fire.
Burning green wood can cause the formation of so much creosote that
it may even run down inside the stove pipe and drip onto the stove
or floor.
Starting
fires
Be sure
to open the damper near the stove before starting a fire. (If you
have a second, higher one, it can remain opoen, for use only in
emergencies.)
Build the fire on a shallow bed of ashes, which provides a heat
reflecting surface. Use a small amount of crumpled paper and cover
it with a few small sticks of wood fuel, says NPFA. When the drafit
is started up the chimney flue, larger pieces of wood can be added.
If the fire burns too slowly, the draft louvers of the stove should
be opened and the damper above the stove pipe opened wider or all
the way. Adjusting the draft and adding frequent but small amounts
of wood make an even burning and continuous hot fire.
Above all, never douse gasoline, kerosene or other flammable fluid
on wood to get a quick fire.
Another way of asking for trouble is to use your stove for trash
burning. The resulting flames can start a chimney fire.
In case
of fire
If you
have a chimney fire, first call the fire department.
While you're waiting for the fireman to arrive, you can help control
the fire by closing the stove's draft louvers and the solid damper
in the stove pipe.
Checks
Before
the heating season each year check and clean your chimney and stove
pipe carefully and make any needed repairs. More frequent checks
are advisable if you are building up creosote and soot.
Unless you are an experienced and competent do-it-yourselfer, think
twice before trying to clean your own chimney - you may damaged
your chimney lining. Rather spend some money on professional service
than create a fire hazard that may cost you thousands of dollars
or even result in the destruction of your home!
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