Heatilator • LM42 • Installers Manual • 4087-901 • Rev A • 04/14/16
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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
Note:
Use same dimensional lumber for framing
ceiling firestop and joists.
2 in. (51mm)
clearance
2 in. (51mm)
clearance
D. Install Firestops
WARNING!
Risk of Fire!
Firestops must be used
whenever the chimney penetrates a ceiling/floor.
• Mark and cut an opening in ceiling/floor as shown in
Figure 5.5.
• Frame the opening.
• Nail the firestop to the bottom of the ceiling/floor joists.
• Provide a means to maintain the required air space
between the chimney and insulation or install an attic
insulation shield.
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 5.5 Installing the Ceiling Firestop
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