Vermont castings ewf36a, Ceiling chimney hole/ possible obstructions, Cutting the hole – Vermont Casting EWF36 User Manual
Page 10: Framing the ceiling hole, Positioning, safety strips, securing the fireplace, Chimney hole size

10
Vermont Castings EWF36A
20005167
Ceiling Chimney Hole/
Possible Obstructions
The size of the hole in ceiling will vary with the angle at 
which the chimney passes through ceiling. 
Drive a nail up through ceiling at marked chimney 
center point. Go to floor above and see where hole 
will be cut. Check to see where existing ceiling joists 
and other possible obstructions are located...i.e. wiring, 
plumbing etc... If necessary, re-position chimney and/or 
fireplace to avoid obstructions.
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 
10. 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: 
FP551b
17 1/2"
Framing chimney hole
5/13/99 djt
Existing
Ceiling
Joists
17¹⁄₂”
(445mm)
17¹⁄₂”
(445mm)
Chimney
Hole
Ceiling
New Framing
Members
FP551b
Fig. 10 Typical frame for ceiling chimney hole.
The inside dimension of the frame must be the same 
as the hole size selected from Figure 9 in order to 
provide required the 2” (51mm) air space between the 
outside diameter of the chimney and the edges of the 
framed ceiling hole.
Positioning, Safety Strips,
Securing the Fireplace
Slide fireplace into position. 
Safety strips are used to ensure that any combustible 
materials in front of the fireplace are protected even 
though a noncombustible hearth extension is required.
When the finished extended hearth is added, the top 
of the finished hearth must be flush with the bottom of 
the fireplace. “Z” shaped metal safety strips have been 
supplied with the fireplace and are required for instal-
lation. The safety strips provided have a 1” offset. For 
applications with a greater offset, “Z” shaped strips will 
have to be fabricated of metal. Overlap safety strips at 
least 1/2” to provide a positive joint. The safety strips 
must also extend at least 1¹⁄₂” (38mm) beyond the sides 
of the fireplace. (Fig. 11)
NOTE: Safety strips are not required over noncombus-
tible floors where all supports at the base of the fire-
place are noncombustible.
Two (2) nailing flanges are supplied with the fireplace. 
To level the box and secure it firmly in place, remove 
the nailing flanges from the hearth and install at the 
sides of the fireplace as shown in Figure 12.
WF557
BR
11/10/97
“Z” Metal Safety
Strips (1 or 2 pcs.)
“Z” Safety
Strip
Hearth Ext.
Fire-
place
Plat-
form
FP557b
1¹⁄₂”
(38mm)
1/2” Min.
Overlap
Fig. 11 Safety strip installation.
Decorative
Hearth
Face
Angle of Chimney at Ceiling
Size of Chimney
Vertical
30°
FS2A
FS6A
8” Flue
17¹⁄₂” x 17¹⁄₂”
17⁷⁄₈” x 29⁵⁄₈”
(445 x 445mm) (454 x 753mm)
Fig. 9 Ceiling chimney hole sizes necessary for installing 
firestop spacer.
Chimney Hole Size
