curbs, hatches, roof jacks, prefabricated flashing
boots, walkways, snow guards, etc.
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Pre-manufactured accessories shall be manufacturer's standard for intended
purpose,[ comply with applicable specification section,] compatible with
the metal roof system and approved for use by the metal roof panel
manufacturer. Curbs shall be constructed to match roof slope.
2.4
FASTENERS
Fasteners for roof panels shall be corrosion resistant coated steel,
aluminum, stainless steel, or nylon capped steel, compatible with the sheet
panel or flashing material and of type and size recommended by the
manufacturer to meet the performance requirements. Fasteners for
accessories shall be the manufacturer's standard. Exposed fasteners shall
have integral metal washer head and compressible sealing EPDM washer.
Sealing washer shall be approximately 2.4 mm (3/32 inch) thick. Exposed
portion of fasteners shall match color of attached material.
2.4.1
Screws
Not smaller than 6 mm (No. 14) diameter self-tapping type and not less than
4 mm (No. 12) diameter self-drilling type.
2.4.2
Rivets
Closed-end type where watertight connections are required.
2.5
UNDERLAYMENTS
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NOTE: Underlayments included in this UFGS are for
slopes of 3:12 or greater. For slopes less than
3:12 other underlayment materials should be used.
Refer to MBMA RSDM and NRCA RWM for guidance.
Select proper underlayment or combination of
underlayment materials. Delete other options.
Consider self-adhering modified bitumen underlayment
for ice dam protection and ridge, hip, valley, and
sidewall areas. Additionally, severe weather
locations, complex roofs, or high value contents
shall consider the higher protection capacity of a
self-adhering modified bitumen underlayment, where
it will not create a condensation concern.
When low perm underlayment is used throughout the
roof area, ensure its vapor retarding effects are
considered such that its use does not create
condensation issues. Consideration for predominant
vapor drive action in hot and cold climates in
combination with building use and location,
insulation location, under deck or attic space
venting, and vapor retarder needs and positioning
should be considered in underlayment selection.
Underlayment in conjunction with an underlying and
properly positioned vapor retarder/barrier may be
SECTION 07412
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