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6. Carefully remove roofing nails from top row of
shingles so that the flashing of the roof vent will
slide under top row. Trim shingles around vent to
allow flashing to slide under shingles and align
vent hole with the hole in roof.
7. Apply roofing cement to the bottom of the vent,
around the hole.
8. Carefully slide vent into place with arrow pointing
up. Make sure throat of vent is centered over vent
hole. Fasten the base to roof decking with roofing
nails as shown below. Keep heads of nails under
shingles to prevent water leakage.
9. Finish mounting by sealing all seams and nails
with roofing cement. Also use roofing cement to
fasten down loose edges of shingles.
5” TYPICAL
1” TYPICAL
Space Roofing Nails As Shown
1” TYPICAL
22.375"
32.000"
5”
T
YPIC
AL
22300_1016
LOMANCO 770D ROOF VENT
INSTALLATION INSTRUCTIONS
THREE
MUST
DO
Steps
to attic ventilation
Install all Exhaust Ventilation at the SAME
HEIGHT within a common attic area.
Installation of exhaust vents at more than one
level on a roof allows the upper exhaust vent to
pull air in from lower exhaust vents rather than
from the intake vents. Intake air must come
from intake vents located near the lower part of
the attic space to properly ventilate the total
attic area and eliminate weather infiltration.
Install ONLY ONE TYPE of Exhaust Ventilation
within a common attic area.
Exhaust Vents pull air from the easiest intake source.
Vent types cannot be mixed. The use of different types of
exhaust vents could make one of the vents act as intake
for the other. Intake air must come from intake vents
located near the lower part of the attic space to properly
ventilate the total attic area and eliminate weather
infiltration.
Install a BALANCED SYSTEM of Intake
and Exhaust Ventilation.
50% Intake Ventilation - Intake vents located
near the lower part of the attic area are required
to balance out your ventilation system.
50% Exhaust Ventilation - Use a Lomanco
Ventilation Selector guide, the calculators at
lomanco.com, or the Lomanco Vent Selector App
to determine the number of vents needed to
properly ventilate an attic to meet the minimum
code ventilation standard.
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