30
For Vertical Terminations -
To locate the vent and in-
stall the vent sections:
• Locate and mark the vent centerpoint on the underside
of the roof, and drive a nail through the centerpoint.
• Make the outline of the roof hole around the centerpoint
nail.
• The size of the roof hole framing dimensions depend on
the pitch of the roof. There
MUST BE
a 1-inch (25.4mm)
clearance from the vertical vent pipe to combustible ma-
terials.
• Mark the roof hole accordingly.
• Cover the opening of the installed vent pipes.
• Cut and frame the roof hole.
• Use framing lumber the same size as the roof rafters
and install the frame securely. Flashing anchored to the
frame must withstand heavy winds.
• Continue to install concentric vent sections up through
the roof hole and up past the roof line until you reach
the appropriate distance above the roof.
WARNING: MAJOR U.S. BUILDING
CODES SPECIFY MINIMUM CHIMNEY
AND/OR VENT HEIGHT ABOVE THE ROOF TOP.
THESE MINIMUM HEIGHTS ARE NECESSARY IN
THE INTEREST OF SAFETY. SEE THE FOLLOW-
ING DIAGRAM FOR MINIMUM HEIGHTS, PROVID-
ED THE TERMINATION CAP IS AT LEAST TWO
(2) FEET FROM A VERTICAL WALL AND 2-FEET
BELOW A HORIZONTAL OVERHANG.
NOTE: This also pertains to vertical vent systems in-
stalled on the outside of the building.
!
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
Figure 32. Minimum Height from Roof to
Lowest Discharge Opening
To seal the roof hole, and to divert rain and snow from the
vent system:
• Attach a flashing to the roof using nails, and use a non-
hardening mastic around the edges of the flashing base
where it meets the roof.
• Attach a storm collar over the flashing joint to form a
water-tight seal. Place non-hardening mastic around the
joint, between the storm collar and the vertical pipe.
• Slide the termination cap over the end of the vent pipe
and rotate the pipe clockwise 1/4 turn.
HORIZONTAL
OVERHANG
VERTICAL
WALL
TERMINATION
CAP
12
X
ROOF PITCH
IS X/ 12
LOWEST
DISCHARGE
OPENING
H (MIN.) - MINIMUM HEIGHT FROM ROOF
TO LOWEST DISCHARGE OPENING
2 FT.
MIN.
2 FT. MIN.
