stretched or shortened. [Provide one layer of asphalt-saturated felt
placed perpendicular to roof slope covered by one layer of rosin-sized
building paper placed parallel to roof slope with side laps down slope and
attached with roofing nails. Overlap side end laps 75 mm 3 inches, offset
seams in building paper with seams in felt.]
3.3.1
Roof Panels
Apply roofing panels with standing seams parallel to slope of roof.
Provide roofing panels in full lengths from ridge to eaves (top to eaves on
shed roofs), with no transverse joints except at the junction of
ventilators, curbs, skylights, chimneys, and similar openings. Form
interlocking rib type panel seams in the field with an automatic mechanical
seamer approved by the manufacturer. Attach panels to structure with
concealed clips which are incorporated into the panel seams. Clip
attachment shall allow roof to move freely and independently of the
structure, except at fixed points as indicated.
3.3.2
Flashings
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NOTE: In the high winds metal will vibrate and
fatigue at fasteners on "normal" spacings. For this
reason, cleated (blind fastened) flashings are not
acceptable, and attachment at 100 to 150 mm 4 to 6
inches on center is customary. Flashing should not
extend a significant distance more than 25 mm one
inch beyond a support or fastener.
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Provide flashing and related closures and accessories in connection with
preformed metal panels [as indicated] and as necessary to provide a
weathertight installation. Install flashing to ensure positive water
drainage away from roof penetrations. Flash and seal roof at ridge, eaves
and rakes, at projections through roof, and elsewhere as necessary.
Accomplish placement of closure strips, flashing, and sealing material in
an approved manner that will ensure complete weathertightness. Details of
installation which are not indicated shall be in accordance with the NRCA CD,
SMACNA Arch. Manual, AA ASM-35, panel manufacturer's printed instructions
and details of the approved shop drawings. Installation shall allow for
expansion and contraction of flashing.
3.3.3
Flashing Fasteners
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NOTE: In the high winds, metal will vibrate and
fatigue at fasteners on "normal" spacings. For this
reason, cleated (blind fastened) flashings are not
acceptable, and attachment at 100 to 150 mm 4 to 6
inches on center is customary. Flashing should not
extend any significant distance more than 25 mm one
inch beyond a support or fastener.
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Fastener spacings shall be in accordance with the panel manufacturer's
recommendations and as necessary to withstand the indicated design loads.
Install fasteners in roof valleys as recommended by the manufacturer of the
panels. Install fasteners in straight lines within a tolerance of 13 mm
1/2 inch in the length of a bay. Drive exposed penetrating type fasteners
SECTION 07612N
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