8
35020 Rev G
06-03
BCBR36 B-VENT GAS APPLIANCE
3. Firestop Spacer/Vent Installation
Frame an opening and install a firestop spacer
whenever the vent penetrates a ceiling/floor area, as
shown in Figure 7. Frame the opening with the same
sized lumber as used in the ceiling/floor joists. Unless
the flue is offset, the hole should be directly above the
appliance. DO NOT pack insulation around the vent.
Assemble vent sections as per manufacturers
specifications.
Figure 7
Installing the Firestop Spacer
4. Chase/Termination Installation
Figure 8 and Table 1 specify minimum vent heights for
various pitched roofs.
These vent heights are necessary for safety and do
not ensure draft-free operation. Trees, buildings,
adjoining roof lines, adverse conditions, etc. may create
a need for a taller vent should down drafting occur.
Figure 8
Vent Height for Vertical Termination
Roof Pitch
H (Min.) Ft.
Flat to 6/12 ................................................ 1.0
6/12 to 7/12 ............................................... 1.25
Over 7/12 to 8/12 ...................................... 1.5
Over 8/12 to 9/12 ...................................... 2.0
Over 9/12 to 10/12 .................................... 2.5
Over 10/12 to 11/12 .................................. 3.25
Over 11/12 to 12/12 .................................. 4.0
Over 12/12 to 14/12 .................................. 5.0
Over 14/12 to 16/12 .................................. 6.0
Over 16/12 to 18/12 .................................. 7.0
Over 18/12 to 20/12 .................................. 7.5
Over 20/12 to 21/12 .................................. 8.0
Table 1
Vent Height
Note:
To ensure proper operation, verify all venting
and the termination are unobstructed.
