Include bracketed phrase only when insulation is to
be applied with hot asphalt.
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Apply ventilating felt in accordance with manufacturer's printed
instructions[, spot-mopped with asphalt to concrete deck]. Extend over
roof cants, up vertical surfaces and terminate under cap flashing; at roof
edges terminate under outside edge of perimeter edge nailers or under
gravel stop fascia.
]3.4
INSULATION INSTALLATION
Apply insulation in two layers with staggered joints when total required
thickness of insulation exceeds 13 mm 1/2 inch. Lay insulation so that
continuous longitudinal joints are perpendicular to direction of [felts for
the built-up] roofing, as specified in Section [_____, "_____"], and end
joints of each course are staggered with those of adjoining courses. When
using multiple layers of insulation, joints of each succeeding layer shall
be parallel and offset in both directions with respect to layer below.
Keep insulation 13 mm 1/2 inch clear of vertical surfaces penetrating and
projecting from roof surface.
[3.4.1
Installation Using Asphalt
Firmly embed each layer in solid asphalt mopping; mop only sufficient area
to provide complete embedment of one board at a time. Provide 10 to 18 kgs
20 to 35 lbs of asphalt per 10 square meters 100 square feet of roof deck
for each layer of insulation. Apply asphalt when temperature is within
plus or minus 15 degrees C 25 degrees F of EVT. Do not heat asphalt above
asphalt's FBT or 275 degrees C 525 degrees F, whichever is less, for longer
than 4 consecutive hours. Use thermometers to check temperatures during
heating and application.
][3.4.2
Installation Using Asphalt on Steel Decks
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NOTE: Delete these requirements and include
paragraph entitled "Installation Using Asphalt" when
a vapor retarder is required over steel decks.
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Secure first layer of insulation [and thermal barrier] to deck with
piercing or self-drilling, self-tapping fasteners. Engage fasteners by
driving them through insulation into top flange of steel deck. Use driving
method prescribed by fastener manufacturer. Insulation joints parallel to
ribs of deck shall occur on solid bearing surfaces only, not over open
ribs. Secure succeeding layers with solid asphalt moppings. Where
insulation is applied over steel deck, long edge joints shall continuously
bear on surfaces of the steel deck. Insulation which can be readily lifted
after installation is not considered to be adequately secured. Insulation
shall be applied so that all roof insulation applied each day is
waterproofed the same day. Phased construction will not be permitted.
Application of impermeable faced insulation shall be performed without
damage to the facing.
][3.4.3
Installation Using Only Mechanical Fasteners
Secure total thickness of insulation with penetrating type fasteners.
SECTION 07220
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