Enclosing Members

structural members (walls, floors, and ceilings, roofs, the clothing of apertures, partitions, and so on) that limit the volume of a building or structure and divide it into separate rooms.

In contrast to supporting members, which absorb weight loads, the main purpose of enclosing members is to protect the rooms from the effects of temperature, wind, moisture, noise, and radiation. This is an arbitrary difference, because the protective and support functions are often combined into a single structure (walls, partitions, floor, ceiling and roof slabs, and so on). Enclosing members are divided into exterior and interior types. The exterior members serve mainly for protection against atmospheric effects, and the interior members are used mainly for subdividing the space in a building and for soundproofing.

According to the method of production, enclosing members may be prefabricated (erected using finished factory-made units), or they may be erected at the construction site. In the latter case, for bricks, concrete, and reinforced concrete, the term “monolithic (cast) enclosing members” is used. Enclosing members are further differentiated according to structure into simple and composite types. The simple (single-layer) members are made from a single type of material or pieces (examples are brick walls, light-concrete panels, and plaster partitions). Composite (laminated) members consist of several elements or layers, such as support, insulation, and decorative layers.

Exterior walls, which determine the architectural appearance of a building, are an especially significant type of enclosing member. The wall material often also characterizes the structural type of the building—large-block, large-panel, wooden (lumber or frame-and-board), or brick. The walls also serve as vertical stiffeners.

The service qualities of external enclosing structures should be appropriate for the local climatic conditions and should provide the necessary health and comfort conditions in the rooms. Suitable interior enclosing members must provide proper insulation from airborne noise and vibration and from heat and moisture from adjoining rooms.

Enclosing members should have high strength, rigidity, and stability and should be fireproof. Their finish, color, and other decorative qualities must also be in accord with the functions of the building and the rooms, thus contributing to the attainment of architectural expressiveness.

An important property of enclosing members is their durability, which depends on the class of building and the materials used, taking into account the actual wear conditions resulting from external effects. When prefabricated structures are used, special attention is devoted to the structural treatment of connections and the quality of the joints (butt joints, bonds, fastenings, and insertion elements), to avoid the possibility of failure of connections during the service life established for the building or structure as a whole.

The main trend in the development of modern enclosing members is toward the use of large, industrially produced prefabricated members with a high degree of readiness for use (including large textured and glazed wall panels, large composite floors and ceilings with a finished floor, and three-dimensional units, or modules, with all surfaces finished); improvement of the design of prefabricated units and their connections to reduce the time-consuming preparation and assembly of the enclosing members and of the building as a whole; reduction of the weight of the members; and use of local structural materials for the production of enclosing members.