National Gypsum Construction Guide

GYPSUM SYSTEMS
Nonload-Bearing Steel Frame Partitions
09 29 00/NGC
BUYLINE 1100
DESCRIPTION
Steel framed drywall partitions
are comprised of steel floor
and ceiling tracks, steel
studs and Gold Bond
Gypsum wallboard which
is attached with self-drilling
drywall screws. Metal
products are to meet or
exceed all applicable
ASTM standards.
Gypsum wallboard may be
applied horizontally or
vertically in single or
double layers. In double
layer construction, the face,
or finish layer, may be
Durasan panels adhesively
applied to the base layer.
For specific fire and sound
ratings for this system, see
test data on pages 11
through 26.
ADVANTAGES
1. Openings provided
throughout the length of
the steel studs permit the
easy horizontal routing of
water, gas and electrical
conduit. These openings
may also be used to install
C.R. Channel stiffeners
where increased rigidity is
required. Interruption of the
floor or ceiling track allows
the vertical installation of
larger utilities.
2. Fire resistance: 1-, 2-, 3-
and 4-hour fire ratings have
been assigned to these
systems (see pages 11-26).
3. Sound resistance: where
a superior Sound
Transmission Class is
required, it can be
achieved through the use
of several variations with
this system.
TECHNICAL DATA
PARTITION HEIGHTS
Light Gauge Steel Studs are
designed to frame nonloadbearing
partitions which
are limited in height by
deflection resulting from
extraneous horizontal
forces. For any given
horizontal load, the amount
of deflection increases as
the height of the partition
increases.
Tables 1 and 2 on the next
page show maximum
partition heights based on
specific design criteria. The
height limits shown are
based on the gypsum
wallboard and the steel
studs acting as a composite
section to provide a
maximum deflection of
L/120, L/240, L/360
(L = partition height in
inches) with a horizontal
load of 5 psf, 7.5 psf, and
10 psf of partition surface.
Increased rigidity may be
obtained by placing
stiffener channels through
the steel stud cut-outs, by
using two layer application
of gypsum wallboard or by
decreasing stud spacing.
Standard 25 and 20 gauge
studs, recommended for
interior partitions, have
height limits as shown in
Tables 1 and 2. Wallboard
must be attached to full
height on both sides of
studs with Type S Bugle
Head Drywall Screws
(Type S-12 for 20 gauge
studs) spaced not more
than 12" o.c. on all studs
when framing is 24" o.c.
and 16" o.c. if framing is
16" o.c. or less. Screw
lengths must be not less
than 3/8" greater than the
total thickness of the
wallboard being fastened.
Light steel 20 gauge studs are
designed for exterior,
nonload-bearing curtain
wall systems, but are also
used for interior partitions
to provide more ridigity or
greater heights than can be
obtained with Standard 25
gauge studs.
LIMITATIONS
1. Maximum stud spacing for
single layer application of
1/2" and 5/8" gypsum
wallboard is 24" o.c. If 3/8"
gypsum wallboard is used,
it must be applied in two
layers, with the second
layer adhesively applied;
24" o.c. stud spacing may
be used.
2. Where long, continuous
runs of this wall system are
employed, control joints
must be provided every 30'
or less.
3. Where structural movement
may impose direct loads on
these systems, isolation
details are required.
4. Partitions should not be
used where frequently
exposed to excessive
moisture unless all surfaces
are waterproofed.
5. To prevent weakening
due to calcining, gypsum
wallboard should not be
exposed to temperatures
over 125˚F for extended
periods of time.
6. Wallboard joints on
single layer, or the face
layer on two layer
applications, shall not
occur within 12" of the
corners of door frames
unless control joints are
installed at the corners.
7. For limitations regarding
selection of doors and
doorframes, refer to table
on page 89.
8. Where reference is made
to nominal gauges, 25
gauge relates to a
minimum base steel of
.0179", and 20 gauge to
.0329".
09 29 00
NATIONAL GYPSUM WALLBOARD PRODUCTS
87