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Majestic Biltmore Series • SB100 • 4013-303 Installers Manual • Rev H • 08/20
D. Secure Offset/Return
E. Install Ceiling Firestops
CAUTION!
Risk of Fire!
Ceiling firestops must be used
whenever the chimney penetrates a ceiling/floor.
• Chase construction requires ceiling firestops at each
floor or every 10 ft. (3.05 m) of clear space.
• The ceiling firestop slows spread of fire and reduces
cold air infiltration.
• Install a ceiling firestop whenever chimney penetrates
ceiling/floor.
• Mark and cut an opening in ceiling as shown in Figure 5.4.
• 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.
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
Note:
Use same dimensional lumber for framing
ceiling firestop and joists.
2 in.
(51mm)
clearance
2 in.
(51mm)
clearance
WARNING! Risk of Fire! DO NOT
seal area between
firestop opening and chimney pipe except where they en
-
ter the attic or leave the warm air envelope of the home
(use 600° F sealant).
Figure 5.4 Installing the Ceiling Firestop
When offsets and returns are joined to straight pipe sec
-
tions, they must be locked into position with the screws
(outer only). To prevent gravity from pulling the chimney
sections apart, the returns and the chimney stabilizers
have hanger straps for securing these parts to joists or
rafters. See Figure 5.3.
* Use # 6 or # 8 sheet metal screw, or larger, no longer
than 1/2 in. (13 mm).
WARNING! Risk of Fire!
• Secure offsets with screws (not to exceed 1/2 in./13 mm
In length).
• Secure returns with strapping.
• Straight chimney sections may be secured with screw
(not to exceed 1/2 in./13 mm In length) at the joints.
• Keep chimney sections from separating or twisting.
Ceiling
Firestop
Straps
Optional
Additional
Support
Joint
Band
(Optional)
Figure 5.3 Secure the Chimney
Catalog #
A
B
in.
mm
in.
mm
FS538
17
432
17
432
FS540
17
432
26
660
