venting installation
Continued
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| Return |
| Return |
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| Elbow |
| Elbow |
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| Return |
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Elbow |
| Elbow |
| Elbow |
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| 6' Max. |
| 6' Max. |
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Return |
| Return |
| Ceiling Support | 6' Max. |
Elbow |
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| Pipe | ||
| Elbow |
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| 6' Max. |
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| Elbow |
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| Elbow | 6' Max. |
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| 6' Max. |
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Elbow |
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| a | B | C |
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Figure 17 - Typical Offset Terminations
Firestop Spacers (FS-10)
Firestop spacers are required at each point where the chimney penetrates a floor space. Their purpose is to establish and maintain the required clearance between the chimney and the combustible materials. When the pipe passes through a framed opening into a living space above, the firestop must be placed onto the ceiling from below as shown in Figure 18.
They also provide complete separation from one floor space to another or attic space as required by most codes. When the double wall pipe passes through a framed opening into an attic space, the firestop must be placed into an attic floor as shown in Figure 19.
Penetrating roof
To maintain a 2" clearance to the pipe on a roof with a pitch, a rectangular opening must be cut.
1.Determine center point through which pipe will penetrate roof.
2.Determine center point of roof. Pitch is distance the roof drops over a given span, usually 12". A 6/12 pitch means that roof drops 6" for each 12" measured horizontally down from roof rafters.
3.Use roof opening chart (Figure 20) to determine correct opening length and flashing required.
4.Remove shingles around opening measured. Cut out this section.
5.Add next sections of pipe until end penetrates roof line. Check to see that proper clearances are main- tained. Extend chimney by adding sections of double wall pipe until pipe is minimum of 30” above highest point of roof cutout. Termination and chimney must extend a minimum of 36” above highest point where it passes through roof.
19.5" Min. | 30" Min. |
|
2" Min.
2" Min.
Firestop
Spacer
Screws or 
Staples 
(Min. of 8)
Existing
Ceiling
Frame
2" Min. 
Opening "A" |
Figure 18 - Firestop Spacer with Living Space | |
Above Ceiling | |
Firestop | Screws or Staples |
Spacer | |
| (Min. of 8) |
Pitch | Slope | Opening | Used Flashing |
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| "A" Max. | Model No. |
Flat | 0° | 19.5" | |
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26.6° | 22' | ||
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45.0° | 27" | ||
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Existing
Ceiling
Frame
Figure 20 - Roof Opening Measurements
Figure 19 - Firestop Spacer with Attic Above
Ceiling
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