3.3
APPLICATION
Apply roofing materials as specified herein unless specified or recommended
otherwise by shingle manufacturer's written instructions
[or by NRCA Shingle Manual].
3.3.1
Underlayment
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NOTE: Select the applicable paragraph(s) from the
following.
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The installation of asphalt strip shingles at
maximum exposure is not recommended on roofs having
a slope of less than 1:4.
In locations where the January mean temperature is
minus one degree C (30 degrees F) or less, a leak
barrier underlayment membrane should be used. The
leak barrier underlayment membrane may consist of:
two plies of No. 15 asphalt saturated felt, one
nailed to the deck and the second set in Type III or
Type IV hot asphalt or asphalt lap cement; a
heavyweight coated base sheet nailed to the deck and
another felt ply or plysheet set in hot asphalt or
asphalt lap cement; or a self adhering modified
bitumen membrane.
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NOTE: In locations where the average daily January
temperature is minus 4 degrees C 25 degrees F or
below, use the second optional paragraph instead of
the first optional paragraph.
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[Provide for roof slopes one in three 4 inches per foot and greater. Apply
one layer of shingle underlayment to roof deck. Lay underlayment parallel
to roof eaves, starting at eaves. Provide minimum 50 mm 2 inch head laps,
100 mm 4 inch end laps, and 150 mm 6 inch laps from both sides over hips
and ridges. Nail sufficiently to hold until shingles are applied. Turn up
vertical surfaces a minimum of 100 mm 4 inches.]
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NOTE: These requirements are intended primarily for
roof slopes between one in 6 and one in 3 2 and 4
inches per foot. They should not be specified for
roof slopes one in 3 4 inches per foot and greater
unless the condition of the note above is met.
Delete bracketed sentence unless eave flashing is
required.
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[Provide for roof slopes [between one in 6 2 inches per foot and one in 3 4
inches per foot] [one in 34 inches per foot and greater]. Apply two layers
to roof deck. Provide a 480 mm 19 inch wide strip as starter sheet to
maintain specified number of layers throughout roof. Lay parallel to
eaves, starting at eaves. Provide minimum 480 mm 19 inch head laps, 150 mm
6 inch laps from both sides over hips and ridges, and 300 mm 12 inch end
laps in the field of the roof. Nail sufficiently to hold until shingles
are applied. Turn up vertical surfaces a minimum of 100 mm 4 inches.
SECTION 07311
Page 10
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