3.3.6.3
Open Roll Roofing Valleys
Provide 450 mm 18 inch wide strip of mineral-surfaced asphalt roll roofing,
of a color to blend with asphalt shingles, and with granular surface facing
down, for the full length of valley as follows:
a.
Center roll roofing strip in valley over underlayment. Lay
centered in valley over felt underlayment and with granular face
down. Nail strip only enough to hold in place. Apply nails in
rows 25 mm one inch from each edge. As fastening along second
side proceeds, press strip firmly into valley.
b.
Center second strip 900 mm 36 inches wide in valley and lay it
over first strip with granular face exposed and nail as specified
for 450 mm 18 inch strip.
c.
Before applying roofing shingles, snap two chalk lines for full
length of valley. Locate each line 75 mm 3 inches from centerline
of valley at top, and increase width between lines by 25 mm for
each 2440 mm one inch for each 8 feet of valley length, continuing
to eaves.
d.
Apply a 50 mm 2 inch band of asphalt roof cement along each edge of
900 mm 36 inch strip from edge to chalk line. Cut regular
shingle courses true along valley chalk lines, and nail in normal
manner.
3.3.6.4
Open Sheet Metal Valleys
Sheet metal flashing for valleys is specified in Section 07600 FLASHING AND
SHEET METAL. Before installing and fastening flashing in place with metal
cleats:
a.
Install single layer of 900 mm 36 inch wide, asphalt-saturated
felt, centered on valley and extending entire length of valley
over felt underlayment.
b.
Cut regular shingle courses on each roof on true line 50 mm 2
inches from valley centerline at top of valley, and increase width
between lines by 25 mm for each 2440 mm one inch for each 8 feet
of valley length, continuing to eaves.
c.
Apply 50 mm 2 inch band of asphalt roof cement over flashing,
along and under side of shingles adjoining valley.
d.
Press shingles tightly into cement, and nail in normal manner,
except apply nails not closer than 125 mm 5 inches to valley
centerline. Do not drive nails through valley flashing.
e.
Provide a 100 mm 4 inch band of asphalt roof cement for fastening
shingle tabs down along open metal gutters.
3.3.7
Flashing
3.3.7.1
Eave Flashing
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NOTE: Select the applicable paragraph(s) from the
SECTION 07311
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