asphalt roof cement not less than 1/16 inch thick for ply felt.
Use hot
asphalt or modified bitumen cement for modified bitumen sheets.
Extend
first stripping ply not less than 100 mm (4 inches) beyond outer
edge of
flange onto roof membrane. Extend each additional ply 100 mm (4
inches)
beyond the edge of the previous ply.
[3.3.5.2
Membrane Flashing at Roof Drain
**************************************************************************
NOTE: Include these requirements where roof drains
are provided.
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Roof drains are specified in Section 15400 PLUMBING SYSTEMS. Flashings for
roof drains are specified in Section 07600 FLASHING AND SHEET METAL.
Extend roofing plies to edge of drain bowl opening at roof drain deck
flange. Neatly fit and press primed roof drain flashing into heavy coat of
asphalt roof cement applied to top of roofing plies. Strip in and
completely cover flashing with two layers of modified bitumen sheet,
extending the first sheet 150 mm (6 inches) on the roofing beyond the edge
of flashing. Extend the cap sheet 150 mm (6 inches) beyond the previous
flashing ply. Bond the two layers to the metal flashing and to each other
with hot asphalt. Securely clamp membrane, metal flashing, and strip
flashing in the flashing clamping ring. Secure clamps so that strip
flashing and metal flashing are free from wrinkles and folds. Trim
membrane, flashing, and stripping flush with inside of clamping ring.
][3.3.5.3
Pre-fabricated Curbs
Prefabricated curbs shall be securely anchored to nailer or other base
substrate as indicated and flashed with modified bitumen flashing membrane.
]3.3.5.4
Set-On Accessories
Where pipe or conduit blocking, supports and similar roof accessories are
set on the membrane, adhere walkpad material to bottom of accessories prior
to setting on roofing membrane. Specific method of installing set-on
accessories must permit normal movement due to expansion, contraction,
vibration, and similar occurrences without damaging roofing membrane. Do
not mechanically secure set-on accessories through roofing membrane into
roof deck substrate.
3.3.5.5
Lightning protection system components shall be flashed or attached to the
roof membrane in a manner acceptable to the roof membrane manufacturer.
[3.3.6
Roof Walkpads
Install walkpads at roof access points and where otherwise indicated for
traffic areas and for access to mechanical equipment, in accordance with
the modified bitumen sheet roofing manufacturer's printed instructions.
Provide minimum 150 mm (6 inch) separation between adjacent walkpads to
accommodate drainage. Provide walkpad [or an additional layer of cap
sheet] under precast concrete paver blocks to protect the roofing.
][3.3.7
Elevated Metal [Walkways] [and] [Platforms]
Install over completed roof system in accordance with Section 05500.
SECTION 07511
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