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Majestic • MERC32IN, MERC32IL Installation Manual • 2401-980 Rev. L • 1/21
E. Vertical Termination Requirements
Install Metal Roof Flashing
• See minimum vent heights for various pitched roofs
(Figure 7.12) to determine the length of pipe to extend
through the roof.
• Slide the roof flashing over the pipe sections extending
through the roof as shown in Figure 7.13.
Roof Pitch H (Min.) Ft.
Flat to 6/12........................................1.0*
Over 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 7.12 Minimum Height From Roof To Lowest Discharge
Opening
HORIZONTAL
OVERHANG
VERTICAL
WALL
GAS DIRECT VENT
TERMINATION CAP
12
X
ROOF PITCH
IS X/ 12
LOWEST
DISCHARGE
OPENING
2 FT.
MIN.
20 INCHES MIN.
H (MIN.) - MINIMUM HEIGHT FROM ROOF
TO LOWEST DISCHARGE OPENING
Figure 7.14 insert Bolt into Brackets
Figure 7.14 insert Bolt into Brackets
NOTICE:
Failure to properly caulk the roof flashing and
pipe seams could permit entry of water.
• Caulk the gap between the roof flashing and the outside
diameter of the pipe.
• Caulk the perimeter of the flashing where it contacts the
roof surface. See Figure 7.13.
• Caulk the overlap seam of any exposed pipe sections
that are located above the roof line.
CAULK
Figure 7.13
Figure 7.13
Assemble and Install Storm Collar
CAUTION!
Risk of Cuts, Abrasions or Flying Debris.
Wear protective gloves and safety glasses during instal-
lation. Sheet metal edges are sharp.
• Slide the storm collar onto the exposed pipe section
and align brackets.
• Insert a bolt (provided) through the brackets and install
nut. Do not completely tighten.
• Slide the assembled storm collar down the pipe section
until it rests on the roof flashing (see Figure 7.14).
• Tighten nut and make sure the collar is tight against the
pipe section.
• Caulk around the top of the storm collar. See Figure 7.15.
* H minimum may vary depending on regional snowfall.
Refer to local codes.
Note:
When installing a silicone or EPDM pipe flashing boot
on a metal roof, it is recommended to put a bead of 100%
silicone sealant where the boot contacts the vent pipe to
prevent the entry of water. Follow the manufacturer’s recom
-
mendations when installing the boot. Climate regions with
frequent temperatures below - 50 °F (-45.6 °C) should use a
silicone flashing boot.