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1. Floor Assembly — Min 4-1/2 in. (114 mm) thick reinforced lightweight or normal weight (100-150 pcf or 1600-2400
kg/m3) structural concrete. Floor may also be constructed of any 6 in. (152 mm) thick UL Classified hollow-core Precast
Concrete Units*.
See Precast Concrete Units category in the Fire Resistance Directory for names of manufactures.
2. Shaft Wall Assembly — The 1 or 2 hr fire rated shaft wall assembly shall be constructed of the materials and in the
manner described in the individual U400, V400 or W400 Series Wall and Partition Design in the UL Fire Resistance
Directory and shall include the following construction features:
A. Steel Floor And Ceiling Runners — "J"-shaped runner, min 4 in. (102 mm) wide with
unequal legs of min 1-1/4 in. (32 mm) and 2-1/4 in. (57 mm), fabricated from min 24 MSG galv
steel. Runners positioned with short leg toward finished side of wall. Runners attached to walls
and floor with steel fasteners spaced max 24 in. (610 mm) OC. As an alternate to the "J"-shaped
floor runner, a min 4 in. (102 mm) wide by 1 or 1-1/4 in. (25 or 32 mm) deep channel formed
from min 24 MSG galv steel may be used.
B. Steel Studs — "C-H"-shaped steel studs to be min 4 in. (102 mm) wide and formed of min 25
MSG galv steel. Studs cut 1/2 to 3/4 in. (13 to 19 mm) less in length than assembly height with
bottom nesting in and resting on floor runner and with top nesting in ceiling runner. Studs spaced
24 in. (610 mm) OC. After installation of gypsum board liner panels (Item 2D), studs secured to
flange of floor runner on finished side of wall only with No. 6 by 1/2 in. (13 mm) long self-drilling,
self-tapping steel screws.
C. Gypsum Board* — 1 in. (25 mm) thick by 24 in. (610 mm) wide gypsum board liner panels.
Panels cut 3/4 in. (19 mm) less in length than floor to ceiling height. Vertical edges inserted in
"H"-shaped section of "C-H" studs. Free edge of end panels attached to long leg of "J" runner
(Item 2A) with 1-5/8 in. (41 mm) long Type S steel screws spaced max 12 in. (305 mm) OC.
D. Gypsum Board* — Gypsum board sheets, 5/8 in. (16 mm) thick Type C, applied vertically or
horizontally in two layers on finished side of wall as specified in the individual U400, V400 or
W400 Series Wall and Partition Design. A max 1/2 in. (13 mm) gap shall be maintained between
the top of the gypsum board and the bottom surface of the concrete floor. The screws attaching
the gypsum board layers to the C-H studs at finished side of wall shall be located 1 to 1-1/2 in.
(25 to 38 mm) below the bottom of the ceiling runner. No gypsum board attachment screws are
to penetrate the ceiling track.
The hourly Assembly, F, FT, FT and FTH ratings of the joint system are dependent on the
hourly rating of the wall.
3. Joint System —Max separation between bottom of floor and top of finished side of wall is 1/2 in. (13 mm)
at time of installation. The joint system is designed to accommodate a max 25 percent compression and
extension from its installed width. The joint system consists of the following:
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XHBN.HW-D-0824 - Joint Systems
12/14/2017
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