MHC36 AND MHR36 INSTALLATION INSTRUCTIONS
2.Chimney Height Requirements (above roof line)
a.Major building codes specify a minimum chimney height above the roof top. These specifications are summarized in what is known as the Ten Foot Rule. This rule states:
“If the horizontal distance from the side of the chimney to the peak of the roof is 10 ft or less, the top of the chimney must be at least 2 ftabove the peak of the roof, but never less than 3 ftin overall height above the highest point where it passes through the roof.
“If the horizontal distance from the side of the chimney to the peak of the roof is more than 10 ft, a chimney height reference point is established on the surface of the roof a distance of 10 ftfrom the side of the chimney in a horizontal plane. The top of the chimney must be at least 2 ftabove this reference point, but never less than 3 ftin height above the highest point where it passes through the roof.” See Figure 8.
b.These chimney heights are necessary in the interest of safety but do not ensure
3.Number of Sections Required
To determine the chimney components needed to complete your particular installation, follow the steps below:
a.Determine the total vertical height of the fireplace installation. This dimension is measured from the base of the fireplace assembly to the point where the smoke exits the termination cap.
b.Subtract the effective height of the fireplace assembly from the overall height of the fireplace installation (measured from the base of the fireplace to the bottom of the termination cap).
c.Refer to Table 2 to determine what components must be selected to complete the fireplace installation.
d.Determine the number of firestop spacers, stabilizers, roof flashing, etc. required to complete the fireplace installation.
Figure 8 - Chimney Height
Table 2
HEIGHT OF CHIMNEY COMPONENTS
Chimney Stabilizer |
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| SL3 | 43/ | " | |
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| 4 |
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Firestop Spacers |
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| FS338 | 0" |
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| FS339 | 0" |
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| FS340 | 0" |
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Offsets/Returns |
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| SL315 | 133/ | 8 | " |
| SL330 | 141/ | 2 | " |
Roof Flashing |
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| RF370 | 0 |
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| RF371 | 0 |
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Chimney Sections* |
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| |
| SL306 | 43/ | " | |
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| 4 |
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| SL312 | 103/ | 4 | " |
| SL318 | 163/ | 4 | " |
| SL324 | 223/ | 4 | " |
| SL336 | 343/ | 4 | " |
| SL348 | 463/4" | ||
* Dimensions reflect effective height
08/04 | 31072 Rev G | 13 |