Apply membrane immediately following application of hot asphalt. Apply hot
asphalt within 2 meters (6 feet) of roll. Do not work ahead with asphalt.
Asphalt shall be completely fluid, with mop temperatures within the
asphalt's EVT range, but not less than 204 degrees C (400 degrees F), at
the instant membrane comes into contact with asphalt. Application of
bitumen between layers shall be such as to provide full, continuous,
uniform coverage and complete contact of hot asphalt with the sheet above
and below. Embed sheets in asphalt. As sheets are being rolled into hot
asphalt, immediately and thoroughly apply uniform positive pressure by
squeegee, roll, or broom to ensure full adhesion and lap seal, eliminate
trapped air and to provide tight, smooth laminations. Avoid excessive
extrusion of asphalt at lap areas. Control asphalt bleed out to
approximately 25 mm (1 inch) maximum.
]3.3.3.2
Torch Applied [Heat Welded] Modified Bituem Membrane [Flashing]
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NOTE: Include the first bracketed sentence if base
flashing may be torch-applied on hot mopped membrane
work. Include requirement to roll lap areas with
weighted roller when heat welding technique is
specified.
Where heat welding is specified, coordinate with
language in "Description of Roof Membrane System"
and other parts of this specification.
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[Base flashing membrane may be torch applied.] Ensure substrate membrane
surfaces are warmed either naturally or by torch during the installation.
Apply heat evenly to underside of roll membrane being installed and exposed
side lap area of previously installed sheet. Provide for slight, uniform
flow of bitumen in front of roll and full width of roll as the material is
being rolled or set into place. Apply uniform positive pressure to ensure
membrane is fully adhered and all laps are sealed. Prior to forming lap
over granulated surfaces, embed granules of the receiving sheet by heating
and troweling-in the granules to form a uniform black compound surface.
[Roll all lap areas with a weighted roller immediately after forming lap.
Provide for visual bleed out of compound in lap areas.][ Avoid overheating
the membrane or burning through to membrane reinforcement. Inspect and
ensure all lap areas are fully sealed.]
[3.3.3.3
Cold Adhesive Applied Modified Bitumen Membrane
Apply cold adhesive with airless sprayer or 6 mm (1/4-inch) saw-toothed
rubber squeegee to prepared surfaces in accordance with membrane
manufacturer's application instructions. Fully cover substrate with
adhesive. Roll or lay membrane in adhesive in accordance with
manufacturer's recommendations and within the time limitations of adhesive
application. Broom the membrane to ensure full contact with adhesive.
Seal laps with adhesive or by heat fusing with torch or hot air welder as
required by membrane manufacturer. Minimize traffic on installed membrane
during the adhesive cure and set time.
][3.3.4
Ventilating Base Sheets
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NOTE: Include this paragraph when ventilating base
sheets are specified in the paragraph entitled
SECTION 07550
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