424WBST Designer Woodburning Fireplaces
Planning Information
Preplanning an installation is very important to ensure safety and to save time and money. An installer must predetermine where a fireplace will be set and how the chimney system will be run.
NOTE: The 424WBST model uses MHSC SK8
Mounting the Fireplace
A fireplace may only be mounted on the following sur- faces:
1.A flat combustible surface.
2.A raised wooden platform.
3.A concrete block or other solid object placed beneath each of the four (4) corners of the fireplace.
The fireplace must be spaced 1/2" (13 mm) from a combustible back wall and 1/2" (13 mm) from a com-
bustible side wall or support. (Page 14, Fig. 20)
Planning the Chimney Run
Determine how the chimney will be run, length of run and chimney components required to complete the job. (Fig. 6) Never install a chimney below minimum heights.
| LT | MODEL SK & | TOTAL | INSTALLED |
| 2 WALL CHIMNEY | LENGTH | LENGTH | |
|
|
| (LT) | (L1) |
| L1 | SK81 | 56O" | 56O" |
|
| SK818 | 56O" | 56O" |
| L1 | SK83 | 56O" | 56O" |
| SK84 | 56O" | 56O" | |
|
|
|
| FP705 |
Fig. 6 | Installed lengths of chimney sections. |
| ||
The Ten Foot Rule
Major U.S. building codes specify a minimum chimney height above the roof top. The “Ten Foot Rule” is a fire safety rule and not a draft rule. To ensure proper draft, it is recommended that you always meet or exceed the “Ten Foot Rule,” especially when installing a termination on a high pitch roof. (Fig. 7)
The key points of the "Ten Foot Rule" are:
1.If the horizontal distance from the chimney to the peak of the roof is 10' (3 m) or less, the top of the chimney must be at least 2' (610 mm) above the peak of the roof, but never less than 3' (914 mm) in height above the highest point where it passes through the roof.
2.If a horizontal distance from the chimney to the peak of the roof is more than 10' (3 m), a chimney height reference point is established on the surface of the roof a distance of 10' (3 m) from the chimney in a horizontal plane. The top of the chimney must be at least 2' (610 mm) above the reference point, but never less than 3' (914 mm) in height above the high- est point where it passes through the roof.
| 0 To 10' |
|
| 2' Min. 3' | 0 To 10' |
| Min. |
|
|
| 2' Min. 3' |
|
| Min. |
| Reference |
|
| Point |
|
|
| AC246 |
Fig. 7 | Ten Foot Rule illustration. | |
In planning a chimney system, it is important to know:
1.The height of a chimney is measured from the hearth to the exit point on the termination.
2.A chimney cannot be offset more than 30° from a vertical plane.
3.A chimney may run straight up or it may be neces- sary to offset it to avoid obstructions.
4.The maximum length of an angled run (total chimney system) is 20' (6m).
5.No more than 2 offsets (4 total 30° elbows in U.S./or 2 total 45° elbows in Canada) per fireplace may be used.
6.A guy wire stabilizer is required for chimneys extend- ing more than 6' (1.8m) above a roof line.
87D1506
