C. Assemble the Chimney Sections
Attach either a straight chimney section or an offset to the top of the fi replace (depending on your installation require- ment). Chimney sections are locked together by pushing downward until the top section meets the stop bead on the lower section.
The inner fl ue is placed to the inside of the fl ue section below it. The outer casing is placed outside the outer casing of the chimney section below it. See Figure 5.4.
Figure 5.4 Assembling Chimney Sections
Note: Inner fl ue and outer liner sections cannot be disas- sembled once locked together. Plan ahead to ensure the proper installation height is achieved with the selected chimney components.
WARNING
Fire Risk
Do NOT install substitute or damaged chimney components.
•MUST use chimney system described in this manual.
•NO OTHER chimney components may be used.
Substitute or damaged chimney components may impair safe operation.
Note: The fi restop spacer MUST be nailed to the bottom of the ceiling joists EXCEPT when the space above is uninsulated and the attic insulation shield is not being used (see Figure 5.5). When the attic insulation shield is used the spacer may be above or below the joist of an insulated ceiling.
ROOM ABOVE
B 
A
Spacer from 
bottom
| ATTIC ABOVE (insulated ceiling) | ||
Spacer from | When attic insulation | ||
shield not used | |||
top |
| ||
|
| ||
Note: Use same dimensional lumber for framing spacer and joists.
| A |
|
| B | ||
Catalog # | in. |
| mm | in. |
| mm |
FS538 | 17 |
| 432 | 17 |
| 432 |
FS540 | 17 |
| 432 | 26 |
| 660 |
Figure 5.5 Installing the Firestop Spacer
Note: You must provide support for the pipe during con- struction and check to be sure inadvertent loading has not dislodged the chimney section from the fi replace or at any chimney joint.
D. Install the Firestop Spacers
•Mark and cut an opening in the ceiling for the spacer being used. See Figure 5.5.
•Frame the opening with the same size lumber used in the ceiling joists.
•Install the fi restop spacer.
CAUTION
•Firestop spacers must be used at ceiling/fl oor.
•Chase construction requires fi restops at each fl oor or every 10 ft (3.05 m) of clear space.
•Use same dimensional lumber as joists.
Firestop slows spread of fire and reduces cold air infi ltration.
18 | Heatilator • ST42A • 35038 Rev G • 02/05 |