424WBST Designer Woodburning Fireplaces
Actual Centerpoint |
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Chimney | 2056O” | ||
(521 mm) | |||
Centerline | |||
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| Side of STR | |
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| Plumb Line | |
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| Plumb Bob | |
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| Imaginary | |
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| Centerpoint | |
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| FP707 | |
Fig. 10 | Locate centerline of chimney with plumb line. | ||
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 cen- ter 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,
Cutting the Hole
Cover fireplace collar opening and cut proper sized chimney hole in chimney. The SK8 pipe allows you to run pipe through a typical 16” on center joist without
cutting joists.
Framing the Ceiling Hole
Frame the ceiling chimney hole as shown in Figure
12.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:
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| Angle of Chimney at Ceiling | |
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Size of Chimney | Vertical | 30° | |
8" Flue | SKFS2A | SKFS6A | |
"SK" Series | 14¹⁄₂" x 14¹⁄₂" | 14¹⁄₂" x 25¹⁄₂" | |
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| (368 x 368 mm) | (368 x 648 mm) |
Fig. 11 Ceiling chimney hole sizes necessary for installing firestop spacer.
The inside dimension of the frame must be the same as the hole size selected from Figure 12 in order to provide the required air space (1¹/₂" (38 mm) with SK8 between the outside diameter of the chimney and the edges of the framed ceiling hole.
Existing | 1456O" | 1456O" | |
Ceiling |
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Joists |
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| Chimney |
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| Hole |
| New Framing |
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| Members |
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| FP551A |
Fig. 12 | Typical frame for ceiling chimney hole. | ||
10 | 87D1506 |