1.6.3
Elastomeric Coating
Prior to applying coating, check polyurethane foam with a moisture
resistance meter to ensure that foam is dry. Apply roof coating between
the temperature ranges of 10 and 43 degrees C (50 and 110 degrees F),
ambient.
1.7
COORDINATION
Roofing operations shall be coordinated with work of other trades to ensure
that components are installed as required to permit continuous
self-flashing of the sprayed polyurethane foam and protective coating
system. The installed roofing system shall be protected from damage.
Damaged areas shall be repaired.
1.8
WORK SEQUENCE
Schedule the work in order to prevent using newly constructed roofing for
storage, walking surface, or material or equipment movement. If access is
necessary, protect new roofing surfaces, flashings, and mechanical
equipment. Repair damage which does occur and notify the Contracting
Officer within 24 hours of the repairs.
1.9
CONTRACTOR'S FOAM SPRAY EQUIPMENT
1.9.1
Applicator
Use an airless foam spray gun of the mechanical, self-cleaning type, that
does not require a flushing solvent during the spray operation.
1.9.2
Equipment Calibration
Fully calibrate the foam metering equipment to monitor each liquid
component to within 2 percent of the foam material manufacturer's required
metering ratio. Calibrate spray equipment each day at start of operations,
after each restart if spraying operations have been terminated for more
than one hour, whenever there is a change in fan pattern or pressure,
whenever slow curing areas are noticed, whenever a change is made in hose
length or working height, and after changeover between materials.
Calibration shall consist of demonstrating that the equipment is adjusted
to deliver components in proper mix and proportion. Calibration test shall
be done on cardboard or plywood on the roof adjacent to the are to be
sprayed.
1.9.3
Metering Equipment Requirements
Use foam metering equipment capable of developing and maintaining the foam
manufacturer's required liquid component pressures and temperatures. Foam
metering equipment shall have gages for visual monitoring. Equipment shall
provide temperature control of foam components to within the temperature
ranges recommended by the foam manufacturer's printed instructions.
1.9.4
Moisture Protection
Protect the surfaces of component supply containers or tanks used to feed
the foam metering equipment from moisture.
SECTION 07570
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