Field-Constructed Chase Top Flashing - Heatilator BIR50-B Installation Manual

• Install the chase top flashing at the top of the chase with
a 1/2 in. minimum air clearance off the top of the chase
construction (Figure 4.13).
• Spacing clips can be field-fabricated as needed out of
24 GA sheet metal or other suitable non-combustible
material (refer to Figure 4.13)
• Insect-guard screening may be added between the
chase and chase top flashing.
• Secure the chase top flashing to the chase with at least
three screws or nails per side.
• When installed, the bottom of the chimney cap must be
at least 6 in. above the chase top flashing.
Storm collar must
1/2 in. air space
be installed 1 in.
established by
off chase top
spacing clips
1/2 in. Air Space
Spacing Clips
Note: 30 spacing clips and
20 ft insert-guard screening
are included with the unit.
Figure 4.13

Field-Constructed Chase Top Flashing

• Field-constructed flashing must be constructed of 24 GA
minimum sheet metal or other suitable non-combustible
materials.
• The flashing must be oversized to allow 1/2 in. air gap
around all four sides.
• Include a minimum 1 in. turn down and a 1/2 in. drip
edge (optional) to prevent water from seeping into the
chase. Refer to Figure 4.16.
• Additional non-combustible structural supports can be
field-fabricated to help support the chase top flashing if
needed, provided the air ventilation requirements are
maintained. See Figure 4.15.
• Spacing clips can be field-fabricated as needed out of
24 GA sheet metal or other suitable non-combustible
material (refer to Figure 4.13), or purchased from Hearth
& Home Technologies.
• Secure the chase top collar section to the field-fabricated
flashing with sheet metal screws or rivets (Figure 4.15).
• Seal chase top collar section to flashing with non-
hardening waterproof sealant to ensure a weather tight
connection. See Figure 4.15.
• Insect-guard screening may be added between the
chase and flashing.
Heatilator • Birmingham BIR50-B Installation Manual • 4059-701 • Rev G • 06/29/15
• Secure the chase top flashing to the chase with at least
three screws or nails per side.
• When installed, the bottom of the chimney cap must be
at least 6 in. above the flashing (Figure 4.16).
Figure 4.14
Chase top
flashing
Roof
radiation
shields
Chase Top
Required
Collar
spacing
clips
Screws
to hold
flashing to
chase top
Additional
Structural Support
Figure 4.15
1 1/2 in. ventilation
opening around
chimney pipe
Figure 4.16
1 1/2 in. ventilation
opening around
chimney pipe
Roof Radiation Shields
placed here
Chase Top Collar
Slope downward
Turn-down
Drip edge
Insect-guard screening
may be added between
chase and chase top
flashing.
Sealant
Screw or
Pop-rivet
Insect
Screen
21