MASONRY CHIMNEY
Warning: When contemplating using an existing chimney, it must first be thoroughly inspected by an authority
having jurisdiction to determine the following:
1. It is a well constructed, lined
masonry chimney, fully in
accordance with Local Building
Codes and the National Building
Code of Canada (NBCC) 9.21 or
NFPA 211
2. It has been thoroughly cleaned of
any soot or creosote residue and
inspected to determine that it is in
good condition.
3. There is no attic insulation of any
type in contact with the chimney
and no insulation stuffed in around
the chimney at any point, for any
reason.
4. There is, as per NBCC 21.9.5 or NFPA 211, the
necessary air space clearance at all points around
the chimney from floor to roof flashing. If the chim-
ney is enclosed in drywall, openings will be required
to verify clearances at all points.
5. Chimney will be used only for the fireplace and may
not be used to vent a furnace, water heater or any
other appliance.
6. If major repairs are required to meet the above
conditions, a new chimney should be constructed.
New chimney installation:
To ensure adequate draft and to facilitate cleaning, the
fireplace must be connected to the chimney using 7"
diameter EXCEL chimney with an elbow. As shown in
(Figure 9), an ICC or other listed 7" rigid stainless steel
liner and a 45° stainless steel elbow are attached to the
chimney and secured in place using a FDM. If you use
a 6 x 10 clay liner you will need to ovalize the stainless
steel liner to fit into the clay liner. It is recommended
that you position your fireplace before building the
chimney. The factory built chimney sections can easily
be installed as the layers of brick are being placed.
NOTE: If the ceiling is high enough some vertical chim-
ney can be installed before the 45° or 30° elbow is
installed.
Existing chimney installation:
If it is difficult to install rigid stainless on an existing chimney a listed stainless steel flex liner can be used. Special
care is to be taken when installing the flexible liner. A positive connection is assured with the masonry adaptor (part
FDM) available from your dealer. The stainless steel flex liner connects to the masonry adaptor with a flexible/rigid
adaptor (part LAF) and is secured with the 3 stainless steel rivets provided. The masonry adaptor is then secured
Figure 10: Chimney installation with chase enclosure
Storm collar
flashing
10 ft.
2 ft.
12” min.
2” min.
clearance
to com-
bustibles
Radiation shield
Onyx AP
Beneath hearth extension
(see page 17)
Insulation
Chase liner of fire rated gypsum
board is recommended (may be
required by local authorities)
Figure 9: Connection to masonry chimney
Excel liner or other liner listed to
ULC-S635, ULC-S640 or UL1777
Clearance as per NBCC
9.21 or NFPA 211
12” min. to
combustible
ceiling
Excel 7” chim-
ney 18” min.
length
Excel elbow
Masonry adaptor
(FDM)
Metal
firestop
No com-
bustible
material in
this area
ONYX AP Owner's Manual
RSF Woodburning Fireplaces
13
