when vapor retarder is provided beneath insulation
or in recover projects when the old roof membrane
remains intact. The vapor retarder should be
specified in Section 07220, "Roof and Deck
Insulation." Coordinate with Section 06100, "Rough
Carpentry," to ensure that kerfed wood nailers are
specified at edge of roof insulation and placed
around periphery. For roofs requiring venting that
are more than 12 meters (40 feet wide), stack
venting should be provided to supplement edge
venting. Underside ventilation for steel decks
should consist of continuous openings 3 mm to 5 mm
(1/8 to 3/16 inch) wide between adjacent deck units.
Coordinate these requirements with appropriate
specification sections.
**************************************************************************
Vents shall be manufactured for the purpose of releasing vapor pressure
from the roofing system by heat and pressure. Vents shall be one-way type
design to prevent reverse flow of moisture laden air into roofing system.
Valve cap shall effectively seal out wind-blown rain and snow and shall not
permit water entry if submerged.
][2.10.2
Pre-fabricated Curbs
Curbs shall be [_____] gauge [G90 galvanized][AZ55 galvalume][_____] with
minimum 100 mm (4 inch) flange for attachment to roof nailers. Curbs shall
provide minimum height of 250 mm (10 inches) above the finished roof
membrane surface.
][2.10.3
Elevated Metal [Walkways] [and] [Platforms]
As specified in Section 05500 METAL: MISCELLANEOUS AND FABRICATIONS.
]][2.11
WALKPADS
**************************************************************************
NOTE: Use walkpads as walkways and at roof access
points and where the roof or areas of the roof are
intended to bear foot traffic for maintenance or
other purposes once a month or more frequently.
**************************************************************************
Roof walkpads shall be polyester reinforced, granule-surfaced modified
bitumen membrane material, minimum [_____] [5 mm] ([_____][200] mils)
thick, compatible with the modified bitumen sheet roofing and as
recommended by the modified bitumen sheet roofing manufacturer. Panels
shall not exceed 1.2 meters (4 feet) in length. Other walkpad materials
require approval of the Contracting Officer prior to installation.
][2.12
PAVER BLOCKS
**************************************************************************
NOTE: Use concrete pavers as walkways on aggregate
surface roofs where the roof or areas of the roof
are intended to bear foot traffic for maintenance or
other purposes once a month or more frequently. Use
paver blocks under heavy bearing components,
irregular base bearings and for support and
SECTION 07550
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