shall not foam upon contact.
(2) Strippability: After asphalt used in the foaming test
application has cooled to ambient temperatures, test coating for
adherence. Should a portion of the sample be readily stripped
clean from surface, do not consider surface to be dry and do not
start application. Should rain occur during application, stop
work and do not resume until surface has been tested by method
above and found dry.]
3.1.2
Surface Preparation
Correct defects and inaccuracies in roof deck surface to eliminate poor
drainage and hollow or low spots and perform the following:
a.
Install wood nailers the same thickness as insulation at eaves,
edges, curbs, walls, and roof openings for securing cant strips,
gravel stops, [gutters,] and flashing flanges. [On decks with
slopes of one in 12 one inch per foot or more, install wood
nailers perpendicular to slope for securing insulation [and for
backnailing of roofing felts]. Space nailers in accordance with
approved shop drawings.]
[b.
Fill or cover cracks or knot holes larger than 13 mm 1/2 inch in
diameter in wood decks as necessary to form an unyielding surface.]
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NOTE: Include the following requirements when a
vapor retarder is required over wood deck or when
insulation is applied directly to the wood deck with
hot asphalt.
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[c.
Cover wood decks with a layer of rosin-sized building paper or
unsaturated felt. Lap sides and ends not less than 75 mm 3 inches.
Nail sufficiently to prevent tearing or buckling during
installation.]
[d.
Cover steel decks with a layer of insulation board of sufficient
thickness to span the width of a deck rib opening, and conforming
to fire safety requirements. Secure with piercing or
self-drilling, self-tapping fasteners of quantity and placement
conforming to FM P7825. Insulation joints parallel to ribs of
deck shall occur on solid bearing surfaces only, not over open
ribs.]
[e.
Solidly apply asphalt primer to [poured] [precast] concrete decks
at the rate of 4 liters per 10 square meters one gallon per 100
square feet of roof surface [, stopping approximately 100 mm 4
inches from joints between the precast concrete units]. Allow
primer to dry thoroughly. [Place felt strips, 100 mm 4 inches or
more in width, over joints, 50 mm 2 inches on each side, between
precast concrete units in a heavy coating of cold-applied asphalt
roof cement.]]
3.2
INSTALLATION OF VAPOR RETARDER
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NOTE: Unless directed otherwise, do not specify a
SECTION 07220
Page 19
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