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ROOM ABOVE (non-insulated ceiling)
ATTIC ABOVE (insulated ceiling)
B
A
Ceilng firestop
attached to bottom
of framing
Ceiling firestop
attached to top of
framing
When attic insulation
shield not used
Note:
Use same dimensional lumber for framing
ceiling firestop and joists.
2 in. (51mm)
clearance
2 in. (51mm)
clearance
Catalog #
A
B
in.
mm
in.
mm
FS338
14-1/2
368
14-1/2
368
FS339
14-1/2
368
18-3/8
467
FS340
14-1/2
368
23
584
Wire Ties
Wire Ties
4" Flex
Figure 8.6 Installing Flex Pipe
CAUTION! Risk of Fire!
Ceiling firestops must be used
whenever the chimney penetrates a ceiling/floor.
• Install a ceiling firestop whenever chimney penetrates
ceiling/floor.
• Mark and cut an opening in ceiling as shown in Figure 8.7.
• Frame the opening with the same size lumber used in
the ceiling joists.
• Nail the ceiling firestop to the bottom of the ceiling joists
when there is a room above.
• Use an attic insulation shield if the ceiling is insulated.
The ceiling firestop may then be attached above or below
the joists.
WARNING! Risk of Fire! DO NOT
seal area between
firestop opening and chimney pipe except where they enter
the attic or leave the warm air envelope of the home (use
600° F sealant).
F. Install Ceiling Firestops
Figure 8.7 Installing the Ceiling Firestop
NOTICE
: The ceiling firestop MUST be nailed to the bottom
of the ceiling joists EXCEPT when the space above is
uninsulated and the attic insulation shield is not being used..
When the attic insulation shield is used the ceiling firestop
may be above or below the joist of an insulated ceiling.
WARNING! Fire Risk
The flex hose must never be compressed or deformed!
Restricting the airflow inside the flex pipe may increase
flue pipe temperatures causing a chase fire.
• Mark and cut an opening in the ceiling for the ceiling
firestop being used. See Figure 8.7.
• Frame the opening with the same size lumber used in the
ceiling joists.
• Install the firestop spacer.
These firestop spacers are designed to provide the minimum
2 in. (51 mm) air space required around the chimney. In all
situations, the firestop spacers are to be nailed to the ceiling
joists from the bottom or fireplace side,
EXCEPT
when the
space above is an insulated ceiling or attic space. In this situ-
ation, the firestop spacer
must
be nailed from the top side
to prevent loose insulation from falling into the required 2 in.
(51 mm) air space around the chimney.