Heatilator ST42A Owner's Manual page 23

Mark the Exit Point of the Roof
Locate the point where the chimney will exit the roof by
plumbing down to the center of the chimney. Drive a nail
up through the roof to mark the center. See Figure 6.3.
Cut Out the Hole in the Roof
Measure to either side of the nail and mark
the 17 in. x 17
17 in. x 26 in. (432 mm x 660 mm)
This is measured on the horizontal; actual length may
be larger depending on the pitch of the roof. Cut out
and frame the opening. See Chapter 25 of the Uniform
Building Code for roof framing details.
WARNING
Fire Risk
• Must maintain 2 in. (51 mm) air clearance
to insulation and other combustible
materials.
Assemble the Chimney Sections Through the
Roof
Continue to add chimney sections through the roof open-
ing, maintaining at least a 2 in. (51 mm) air space to com-
bustible materials.
Install the Roof Flashing
If a roof fl ashing is to be used, install the roof fl ashing
appropriate to the roof pitch and install a round termination
cap and storm collar following the instructions shipped with
the cap.
Install the Chimney Air Kit (required in Canada):
When installing the chimney air kit, follow the instructions
provided with this accessory.
in. (432 mm x 432 mm)
opening required.
Heatilator • ST42A US-CAN • 4012-039 Rev D • 11/07
or
Figure 6.3 Ceiling/Attic Construction
23