2.1.8
Asphalt Primer
ASTM D 41.
2.1.9
Ventilators
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NOTE: Drawings should detail type of ridge vent
required. For aluminum ridge vents, see Section
07600, "Flashing and Sheet Metal".
Ventilation should be required with a total net free
ventilating area of not less than 1 to 150 of the
area of the space ventilated. The total area is
permitted to be reduced to 1 to 300, provided at
least 50 percent and not more than 80 percent of the
required ventilating area is provided by ventilators
located in the upper portion of the ventilated space
at least 914 mm (3 feet) above eave or cornice
vents, with the balance of required ventilation
provided by eave or cornice vents. As an
alternative, the net free cross-ventilation area may
be reduced to 1 to 300 when a vapor barrier having a
transmission rate not exceeding 1 perm is located on
warm side of the attic insulation.
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2.1.9.1
Nailable Plastic Shingle Over Type Ridge Vents
Ridge vents shall be constructed of UV stabilized nailable rigid
polypropylene material, approximately 0.30 m 1 foot wide and 25 mm 1 inch
thick, and shall be in 1.2 m 4 foot long interlocking sections with
self-aligning ends or corrugated polyethylene rigid roll or rigid strip
ridge vent with aluminum wind deflectors on each side. Vents shall be
designed to prevent infiltration of insects, rain, and snow.
2.1.9.2
Nailable Mesh Shingle Over Type Ridge Vents
Ridge vents shall be constructed of UV stabilized nailable polyester mesh
material, approximately 0.30 m one foot wide. Vents shall be designed to
prevent infiltration of insects, rain, and snow.
PART 3
EXECUTION
3.1
VERIFICATION OF CONDITIONS
Ensure that roof deck is smooth, clean, dry, and without loose knots. Roof
surfaces shall be firm and free from loose boards, large cracks,and
projecting ends that might damage the roofing. Vents and other projections
through roofs shall be properly flashed and secured in position, and
projecting nails shall be driven flush with the deck.
3.2
SURFACE PREPARATION
Cover knotholes and cracks with sheet metal nailed securely to sheathing.
Flash and secure vents and other roof projections, and drive projecting
nails firmly home.
SECTION 07311
Page 9
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