14 Ussc
Combustible Wall Chimney Connector Pass-Throughs
Method A.
12” (304.8 mm) Clearance to Combustible Wall Mem-
ber:
Using a minimum thickness 3.5” (89 mm) brick and a 5/8”
(15.9 mm) minimum wall thickness clay liner, construct a wall pass-
through. The clay liner must conform to ASTM C315 (Standard
Specification for Clay Fire Linings) or its equivalent. Keep a mini-
mum of 12” (304.8 mm) of brick masonry between the clay liner and
wall combustibles. The clay liner shall run from the brick masonry
outer surface to the inner surface of the chimney flue liner but not
past the inner surface. Firmly grout or cement the clay liner in place
to the chimney flue liner.
Method B.
9” (228.6 mm) Clearance to Combustible Wall Member:
Using a 6” (152.4 mm) inside diameter, listed, factory-built Solid-
Pak chimney section with insulation of 1” (25.4 mm) or more, build
a wall pass-through with a minimum 9” (228.6 mm) air space be-
tween the outer wall of the chimney length and wall combustibles.
Use sheet metal supports fastened securely to wall surfaces on all
sides, to maintain the 9” (228.6 mm) air space. When fastening
supports to chimney length, do not penetrate the chimney liner (the
inside wall of the Solid-Pak chimney). The inner end of the Solid-
Pak chimney section shall be flush with the inside of the masonry
chimney flue, and sealed with a non-water soluble refractory ce-
ment. Use this cement to also seal to the brick masonry penetra-
tion.
Method C.
6” (152.4 mm) Clearance to Combustible Wall Member:
Starting with a minimum 24 gage (.024” [.61 mm]) 6” (152.4 mm)
metal chimney connector, and a minimum 24 gage ventilated wall
thimble which has two air channels of 1” (25.4 mm) each, construct
a wall pass-through. There shall be a minimum 6” (152.4) mm sep-
aration area containing fiberglass insulation, from the outer surface
of the wall thimble to wall combustibles. Support the wall thimble,
and cover its opening with a 24-gage minimum sheet metal sup-
port. Maintain the 6” (152.4 mm) space. There should also be a
support sized to fit and hold the metal chimney connector. See that
the supports are fastened securely to wall surfaces on all sides.
Make sure fasteners used to secure the metal chimney connector
do not penetrate chimney flue liner.
Method D.
2” (50.8 mm) Clearance to Combustible Wall Mem-
ber:
Start with a solid-pak listed factory built chimney section at
least 12” (304 mm) long, with insulation of 1” (25.4 mm) or more,
and an inside diameter of 8” (2 inches [51 mm] larger than the 6”
[152.4 mm] chimney connector). Use this as a pass-through for
a minimum 24-gauge single wall steel chimney connector. Keep
solid-pak section concentric with and spaced 1” (25.4 mm) off the
chimney connector by way of sheet metal support plates at both
ends of chimney section. Cover opening with and support chimney
section on both sides with 24 gage minimum sheet metal supports.
See that the supports are fastened securely to wall surfaces on all
sides. Make sure fasteners used to secure chimney flue line
.
NOTES:
1. Connectors to a masonry chimney, excepting method B, shall extend in one continuous section
through the wall pass-through system and the chimney wall, to but not past the inner flue liner face.
2. A chimney connector shall not pass through an attic or roof space, closet or similar concealed
space, or a floor, or ceiling.
