Installation Guide

1. Ensure Proper Intake Ventilation...
Always ensure there is proper intake ventilation at the
soffit, undereave, or fascia areas of the roof. This is
required for a balanced attic ventilation system. Use
the chart located on the outside of the package to
ensure the minimum recommended intake ventilation
is installed on the home. Always consult local building
codes for ventilation requirements.
2. Locate Position...
Locate the vent as high as possible on the roof, but not
on the ridge line. The top opening of the hood must
be 24" (609 mm) BELOW the ridge line (FIGURE 1a).
Single vents should be centered; multiple vents should
be evenly spaced over the length of the roof. Measure
from the ridge line to the top center of the vent hood
(FIGURE 1b). Using this measurement, go inside the
attic and mark the location centered between two
rafters and drill a hole. Put an object such as a pencil
through the hole so that it is visible on the outside
(FIGURE 1c).
3. Mark and Cut Opening...
Place and center the template (included on the box)
over the previously marked hole. Using a pencil or
marker, use the template as a guide to mark a circle.
Note: The included cutout template on the box will
be 15" (381 mm) in diameter. For 24" (609 mm)
on-center rafters, make the cutout shown in FIGURE 2a.
For 16" (406 mm) on-center rafters, make the cutout
shown in FIGURE 2b. Using a power saber, jig saw, or
hand saw, cut out the opening (FIGURE 3a).
4. Prepare the Opening...
Roll back and separate any shingles (if existing).
Remove all nails within 5 ½" (140 mm) from the
sides and top of the opening.
5. Test Vent Position…
Test the final position of the vent by sliding the flashing
up under the upper shingles. Trim any shingles as
needed and remove the vent (FIGURE 3b).
6. Seal and Fasten Vent...
With the position tested, apply a bead of roofing
cement or urethane sealant to the underside of the
vent’s flashing. Proceed with sliding the vent up under
the top shingles, with arrow on the flashing pointing
up. Leave the lower portion of the vent flashing on
top of the shingles for maximum weather resistance.
Using roofing nails, fasten the vent at all corners of the
flashing and approximately every 4" (102 mm) along
the edge of the flashing (FIGURE 4).
Note: For maximum wind resistance, remove the
vent hood and fasten the flashing every 45 degrees,
approximately 1" (25.4 mm) away from the stack wall.
Replace vent hood when complete. Seal all exposed
fasteners, flashing, stack seams, and loose shingles.
Warning: Using excess roof cement may cause
blistering in the roofing shingles.
Note: In the unlikely event accessories or parts are missing
or this product does not operate correctly, please contact
Master Flow
®
Technical Services at 1-800-211-9612. Do
NOT return this vent to retailers or distributors.
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©2016 GAF 3/16 • #498 1 Campus Drive, Parsippany, NJ 07054
Note: See Figures on previous page.
ATTIC EXHAUST VENT
Installation Instructions
For High-Capacity
Dome Vent
High-Capacity Dome Vent