permission from Grinnell Mutual Reinsurance Company, I-80 & Hwy 146,
Grinnell, Iowa 50112)
Chimneys and Vents
Gas fired appliances equipped with
draft hoods and other equipment listed for use with Type B gas vents
may be connected to Type B vents, that have a one inch clearance
from combustible material. Appliances and heating systems
burning wood, coal, or oil should use an approved masonry, UL or ULC
listed prefabricated all fuel chimney. chimneys should have at
least a two inch clearance from combustible material.
Chimneys or gas vents should
terminate three feet above the point where they pass through the
roof and at least two feet higher than any portion of a building
with ten feet of the chimney or vent.
Provide openings into attic spaces to
permit yearly chimney inspections.
Chimneys and gas vents should be
checked and maintained on a periodic basis.
B. Smoke Pipes-Chimney Connectors
A double wall ventilated metal
thimble three times the diameter of the chimney connector should be
used if the chimney connector passes through an interior wall.
Smoke pipe should have an air tight
connection into the flue opening using either a thimble or cemented
in place using refractory cement.
Provide at least 18 inches of
clearance from smoke pipe to combustible material. Clearances
can be reduced when the combustible material is protected in
accordance with National Fire Protection Association's pamphlet #211
- Chimneys, Fireplaces, Vents, and Solid Fuel Burning Appliances.
Chimney connectors shall be as short
as practical, (not longer than 10 feet), make no more than two 90
degrees bends, and slope 1/4 inch per foot from stove toward
Joints in a woodburning stove pipe
should fit tightly, be secured with sheet metal screws, and should
be assembled to funnel any liquid creosote accumulating in the pipe
back to the stove where it will burn.
C. Heating Systems
All heating systems should be tested
and listed by a recognized testing agency such as Underwriters
Laboratories or the American Gas Association.
Clearances to combustible material
for agricultural heaters (suspended unit, portable, electric, etc.)
and residential heaters (such as furnaces, boilers, portable
heaters, etc.) need adequate clearance from floors, walls, ceilings,
and other combustible material in accordance with the clearances
specified on their nameplate or appropriate National Fire Protection
Association code book.
Clearances for woodburning stoves to
combustible walls shall be 36 inches unless specified differently on
their nameplate. Adequate floor protection is also needed
depending upon the type of unit and height of the legs.
Establish a routine maintenance
program before each heating season. Furnaces, boilers, oil
burners, wood burners and their operating and safety controls, vents
and chimneys should be checked by a qualified serviceman.
The fuel supply lines plus all
connections and joints should be tight, securely supported, and
protected from physical damage.