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Here is a checklist to follow when installing or checking a flue
pipe assembly. It is based on the requirements found in the
Canadian Standards Association’s Installation Code for Solid
Fuel Burning Appliances and Equipment (Standard B365).
1)
Single-wall flue pipe assemblies must not exceed
3 metres (10' ) in overall length.
2)
The assembly should be as short and direct as possible.
3)
A single-wall flue pipe assembly must have no more than
two 90 degree elbows; use 45 degree elbow, wherever
possible.
4)
Do not use galvanized flue pipe because the coating can
vaporize at high temperatures, emitting poisonous gases
and leaving the pipe thin and weak.
5)
Flue pipes for woodburning appliances need to be thicker
than those used for other fire-burning appliances; 24
gauge for 150 mm (6") .
6)
Joints between pipes should overlap at least 30mm
(1 1/4").
7)
Each joint should be secured with three sheet metal
screws.
8)
The assembly should be constructed to allow for expansion.
Elbows in an assembly allow it to expand; straight flue
pipe assemblies should have one section left unscrewed
and secured with an inspection wrap clamped around the
joint.
9)
The pipes should slope up towards the chimney at least
20 mm/metre (1/4 in/ft).
10) One end of the flue pipe assembly must be securely
fastened to the flue collar of the appliance and the other
end fastened to the chimney.
11) There must be provision for the cleaning and inspection of
the pipes by removal of the pipe. The removal of the pipes
should not require moving the appliance.
12) The crimped ends of the pipes should point towards the
appliance so that condensation drains to the appliance
and does not leak out.
13) A flue pipe must never pass through a combustible floor or
ceiling, or through a concealed attic, roof space, or closet.
Flue pipe assemblies should be stable and secure. To check
the stability of a flue pipe assembly, grasp it at its mid-point
and give it a good shake. If it is properly constructed, it will have
little or no movement.
Masonry chimneys should be checked for deterioration
including damaged bricks, crumbling and missing mortar,
cracks in the drip cap at the top of the chimney, and loose
flashings at the roof line. The liner should be checked for
cracks and mis-alignment, and its size should be 6".
An existing factory-built metal chimney needs a careful
inspection. Your new cookstove should be connected only to
factory-built chimneys approved to ULC Standard S629 in
Canada and UL 103HT in the U.S. Possible problems with an
older metal chimney can include a warped or buckled liner
caused by the heat of a chimney fire, corrosion of the outer
shell, a loose flashing, and a lack of proper support. Any
discolouration of the metal shell near a joint indicates that the
insulation has settled. A damaged metal chimney should be
replaced with a new approved chimney which will be safer and
will perform better.
Safety Practices
What To Do If You Have a Chimney Fire
1)
Close all the combustion air dampers on the appliance.
2)
Call the fire department immediately.
3)
Be prepared to get everyone out of the house in case the
fire spreads
4)
Go outside and check to see that hot ashes do not ignite
shingles.
5)
Watch anything near the chimney that could catch fire and
burn.
6)
After the fire has run its course and the chimney has
cooled,
have the chimney thoroughly inspected to
determine if it sustained any damage.
7)
Resolve to inspect and clean the chimney more often to
prevent another chimney fire.
Flue Pipes
Flue pipes carry the exhaust gases from the appliance flue
collar to the chimney. The flue pipe assembly is an extremely
important part of a woodburning systems and should be
carefully planned and installed.
