9
ODSHR Series
20002264
Cutting the HoleCover fireplace collar opening and cut proper sized
chimney hole in chimney. (Fig. 10 & 11)
Framing the Ceiling HoleFrame the ceiling chimney hole as shown in Figure 11.
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:
The inside dimension of the frame must be the same
as the hole size selected from Figure 10 in order to
provide the required 2 inches of air space between the
outside diameter of the chimney and the edges of the
framed ceiling hole.
Angle of Chimney at Ceiling
Size of Chimney Vertical 30˚
11" CF 2-Wall FS2A
17¹⁄₂" x 17¹⁄₂"FS6A
17⁷⁄₈" x 29⁵⁄₈"
CHIMNEY HOLE SIZE
FP548b
Fig. 10 Ceiling chimney hole size necessary for installing
firestop spacer.
New Framing
Members
Existing
Ceiling
Joists
Chimney
Hole
17¹⁄₂"17¹⁄₂"
FP551b
Fig. 11 Typical frame for ceiling chimney hole.