Level 4 in accordance with GA 214. Unless otherwise specified, all gypsum
board walls, partitions and ceilings shall be finished to Level 5 in
accordance with GA 214. Provide joint, fastener depression, and corner
treatment. Do not use fiber glass mesh tape with conventional drying type
joint compounds; use setting or hardening type compounds only. Provide
treatment for water-resistant gypsum board as recommended by the gypsum
board manufacturer.
3.4.1
Uniform Surface
Wherever gypsum board is to receive eggshell, semigloss or gloss paint
finish, or where severe, up or down lighting conditions occur, finish
gypsum wall surface in accordance to GA 214 Level 5. In accordance with GA
214 Level 5, apply a thin skim coat of joint compound to the entire gypsum
board surface, after the two-coat joint and fastener treatment is complete
and dry.
[3.4.2
Metal Trim for Predecorated Gypsum Board
Finish edges, ends, and joints of predecorated gypsum board, except
prefinished vee joints and monolithic type joints, with metal or plastic
trim selected to match the gypsum board finish.
]3.5
SEALING
Seal openings around pipes, fixtures, and other items projecting through
gypsum board and cementitious backer units as specified in Section 07920
JOINT SEALANTS. Apply material with exposed surface flush with gypsum
board or cementitious backer units.
[3.5.1
Sealing for Glass Mat or Reinforced Gypsum Board Sheathing
Apply silicone sealant in a 9.5 mm3/8 inch bead to all joints and trowel
flat. Apply enough of the same sealant to all fasteners penetrating through
the glass mat gypsum board surface to completely cover the penetration when
troweled flat. [Construction and materials shall not be placed behind
sheathing until a visual inspection of sealed joints during daylight hours
has been completed by Contracting Officer.]
]3.6
FIRE-RESISTANT ASSEMBLIES
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NOTE: Coordinate with the drawings to ensure that
UL or GA design numbers are indicated for
fire-resistant assemblies. If review of building
code requires pressurized enclosures, include the
following:
Pressurized fire-rated gypsum board enclosures shall
allow the mechanical and electrical life-safety
systems to operate in accordance with the design
intent. Air pressure within elevator shaft shall be
360 Pa. 7.5 psf. Air pressure within stair shaft
shall be 240 Pa. 5.0 psf. Maximum mid-span
deflection shall be L/360.
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Wherever fire-rated construction is indicated, provide materials and
application methods, including types and spacing of fasteners,[ wall[ and
SECTION 09250
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