Building Design and Construction Handbook - Merritt - Ventech!

WALL, FLOOR, AND CEILING SYSTEMS 11.43
wall movements. Batten mullions consist of inner and outer cap sections that clamp
the edges of adjacent panels, but not so tightly as to restrict movement in the plane
of the wall. Structural gaskets provide a flexible link between mullions and panels.
To accommodate vertical movement, mullions are spliced with a telescoping slip
joint.
When mullions are not used and wall panels are connected to each other along
their vertical edges, the connection is generally made through deep flanges. With
the bolts several inches from the face of the wall, movement is permitted by the
flexibility of the flanges.
Slotted holes are unreliable as a means of accommodating wall movement,
though they are useful in providing dimensional tolerance in installing wall panels.
Bolts drawn up too tightly or corrosion may prevent slotted holes from functioning
as intended. If slotted holes are used, the connections should be made with shoulder
bolts or sleeves and Bellville or nylon washers, to provide light but positive pressure
and prevent rattling.
Since metals are good transmitters of heat, it is particularly important with metal
curtain walls to avoid thermal short circuits and metallic contacts between inner
and outer wall faces. When, for example, mullions project through the wall, the
inner face should be insulated, or each mullion should comprise two sections separated
by insulation.
For more details on curtain walls, see W. F. Koppes, ‘‘Metal Curtain Wall Specifications
Manual,’’ National Association of Architectural Metal Manufacturers, 600
S. Federal St., Chicago, IL 60605; ‘‘Curtain Wall Handbook,’’ U.S. Gypsum Co.,
Chicago, IL 60606.
PARTITIONS
Partitions are dividing walls one story or less in height used to subdivide the interior
space in buildings. They may be bearing or nonbearing walls. (See also Art. 1.7.)
11.22 TYPES OF PARTITIONS
Bearing partitions may be built of masonry or concrete or of wood or light-gage
metal studs. These materials may be faced with plaster, wallboard, plywood, wood
boards, plastic, or other materials that meet functional and architectural requirements.
Masonry partitions should satisfy the requirements of Arts. 11.2 to 11.12.
See also Art. 11.14.
Nonbearing partitions may be permanently fixed in place, temporary (or movable)
so that the walls may be easily shifted when desired, or folding. Since the
principal function of these walls is to separate space, the type of construction and
materials used may vary widely. They may be opaque or transparent; they may be
louvered or hollow or solid; they may extend from floor to ceiling or only partway;
and they may serve additionally as cabinets or closets or as a concealment for
piping and electrical conduit.
Fire resistance sometimes dictates the type of construction. If a high fire rating
is desired or required by local building codes, the local building official should be
consulted for information on approved types of construction or the fire ratings given