CFM Corporation ODSHR42 - Manual (Page 10)

10
ODSHR Outdoor Woodburning Fireplace
20002264
Cutting the Hole
Cover fireplace collar opening and cut proper sized
chimney hole in chimney.
Framing the Ceiling Hole
Frame the ceiling chimney hole as shown in Figure
13. It is good practice to use framing lumber that is the
same size as the ceiling joists; this is a requirement at
attic level.
The following table gives firestop spacer model num-
bers:
Chimney Hole Size
FP551b
SHR
5/11/99 djt
New Framing
Members
Existing
Ceiling
Joists
Chimney
Hole
17¹⁄₂"
(445 mm)
17¹⁄₂"
(445 mm)
FP551b
Fig. 13 Typical frame for ceiling chimney hole.
Fig. 12 Ceiling chimney hole size necessary for installing
firestop spacer.
Angle of Chimney at Ceiling
Size of Chimney Vertical 30°
11" CF 2-Wall 17¹⁄₂" x 17¹⁄₂" 17⁷⁄₈" x 29⁵⁄₈"
(445 x 445 mm) (454 x 753 mm)
The inside dimension of the frame must be the same
as the hole size selected from Figure 12 in order to
provide the required 2" (51 mm) of air space between
the outside diameter of the chimney and the edges of
the framed ceiling hole.