C (500 and 525 degrees F) for longer than four consecutive hours. Do not
heat asphalt to the flash point (FP). Apply asphalt and embed membrane
sheets when temperature of asphalt is within plus or minus 14 degrees C (25
degrees F) of the equiviscous temperature (EVT) but not less than 204
degrees C (400 degrees F). Before heating and application of asphalt refer
to the asphalt manufacturer's label or bill of lading for FP, FBT, and EVT
of the asphalt used.
]]3.2.4
Priming of Surfaces
Prime all surfaces to be in contact with adhered membrane materials. Apply
primer at the rate of 3 liters per 10 sq. meters (0.75 gallon per 100 sq.
ft.) or as recommended by modified bitumen sheet manufacturer's printed
instructions to promote adhesion of membrane materials. Allow primer to
dry prior to application of membrane materials to primed surface. Avoid
flammable primer material conditions in torch applied membrane applications.
3.2.4.1
Priming of Concrete and Masonry Surfaces
**************************************************************************
NOTE: Include this paragraph when roofing and
flashing are applied directly to concrete or masonry
surfaces.
**************************************************************************
After surface dryness requirements have been met, coat concrete and masonry
surfaces which are to receive membrane materials uniformly with primer.
3.2.4.2
Priming of Metal Surfaces
Prime flanges of metal components to be embedded into the roof system prior
to setting in bituminous materials or stripping into roofing system.
3.2.5
Membrane Preparation
Unroll modified bitumen membrane materials and allow to relax a minimum of
30 minutes prior to installation. In cold weather, adhere to membrane
manufacturer's additional recommendations for pre-installation membrane
handling and preparation. Inspect for damage, pinholes, particles of
foreign matter, undispersed raw material, factory splices, or other
conditions that might affect serviceability. Edges of seams shall be
straight and flat so that they may be seamed to one another without forming
fish mouths or wrinkles. Discard damaged or defective materials.
3.2.6
Substrate Preparation
Apply membrane to clean, dry surfaces only. Membrane shall not be applied
to surfaces that have been wet by rain or frozen precipitation within the
previous 12 hours. Provide cleaning and artificial drying with heated
blowers or torches as necessary to ensure clean, dry surface prior to
membrane application.
3.3
APPLICATION
Apply roofing materials as specified herein unless approved otherwise by
the Contracting Officer. Keep roofing materials dry before and during
application. Complete application of roofing in a continuous operation.
Begin and apply only as much roofing in one day as can be completed that
same day. Maintain specified temperatures for asphalt. [Provide temporary
SECTION 07550
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