CHIMNEY REQUIREMENTS
VENTING COMPONENTS
Chimney Connector:
It is also known as flue pipe or stove pipe. The chimney
connector joins the stove to the chimney. It must be a
6 inch (152mm) minimum diameter 24 gauge mild steel
black steel, or an approved air-insulated double wall
venting pipe.
Thimble:
A manufactured or site-constructed device installed in
combustible walls through which the chimney connec-
tor passes to the chimney. It is intended to keep the
walls from igniting. Site constructed thimbles must meet
NFPA 211 Standards. Prefabricated must be suitable
for use with selected chimney and meet UL103 Type HT
Standards. Follow instructions provided by the manu-
facturer for manufactured thimbles for masonry chimney
and prefabricated chimneys.
Chimney:
The chimney can be new or existing, masonry or prefab-
ricated and must meet the following minimum require-
ments specified in Section 5B.B.
CHIMNEY SYSTEMS
Prefabricated Metal Chimney
• Must be a 6 inch (152mm) diameter (ID) high tempera-
ture chimney listed to UL 103HT (2100°F) or ULC S627.
• Must use components required by the manufacturer for
installation.
• Must maintain clearances required by the manufacturer
for installation.
• Refer to manufacturers instructions for installation.
Thimble
Site constructed for masonry chimney installation:
Components
• A minimum length of 12 inches [05mm] (longer for
thicker walls) of solid insulated factory-built chimney
length constructed to UL 103 Type HT 6 inch (152mm)
inside diameter. Chimney needs to extend a minimum of
2 inches (51mm) from the interior wall and a minimum of
1 inch (25mm) from the exterior wall.
• Wall spacer, trim collar and wall band to fit solid pack
chimney selected.
• Minimum 8 inch (20mm) diameter clay liner section (if
not already present in chimney) and refractory mortar.
Air Clearances
• Masonry chimney clearance must meet NFPA 211
minimum requirement of 2 inches (51mm) to sheet metal
supports and combustibles.
• Minimum of 1 inch (25mm) clearance around the chim-
ney connector.
Figure 6.1
Solid Pack Chimney with Metal Supports as a Thimble
Figure 7.1
Fire Risk.
Do NOT pack insulation or other combustibles
between spacers.
• ALWAYS maintain specified clearances around
venting and spacers.
• Install spacers as specified.
Failure to keep insulation or other material away
from vent pipe may cause fire.
8
WARNING