Designing and Installing a Safe System
Almost every commercial and public building, whether it is an office building, sports arena, place of worship, or school building, contains a guardrail system. Guardrail systems are installed to provide safety and protection for the building occupants and are placed at or near the outer edges, of flights of stairs, ramps, landings, platforms, balconies and accessible areas of roofs. They will also be found at the perimeter edge of any opening or accessible surface, such as an opening for a stairway, or at a location where operating conditions require limited access to a designated area in order to guard against accidental falls.
05 50 00 Metal Fabrications
Designing and Installing a Safe System
Metal railing systems are a typical solution for applications that include stairs, ramps, drop offs and uneven walkways. Metal railings utilize the same basic structural components as wood railings; a top handrail, a bottom rail or track, balusters or newel posts for main load transfer to the walking surface, and infill panels, pickets or spindles.
Formed metal fabrications include column covers, metal panels, and other metal fabrications that are used in the building industry. Through a variety of different processes, most metals can be formed into virtually any shape. Metal forming processes include roll forming, stamping and brake forming. All processes begin with sheet metal of varying gauges – a higher gauge corresponds to a thinner sheet. Aluminum, stainless steel and galvanized steel are all common materials used to fabricate formed metal components.
Metal casting is the process in which metal is melted and poured into molds, where it is allowed to solidify. Metal casting is one of the world’s largest industries, with over 2000 metal casters producing 13 to 15 million tons of castings annually. Metal casting is often used for making complex shapes which would otherwise be difficult or more expensive to produce.
This topic includes information related to metal stair treads and nosings installed during construction. Metal stair treads and nosings are fabricated portions of a stairway used for foot traffic from floor to floor within a structure. Stair treads may be solid plate, bar or plank grating and are commonly made from aluminum or steel.
This topic includes information related to metal floor plates installed during construction. Metal floor plates are solid floor plates with rough surfaces, treads or small perforated holes. Metal floor plates are used to cover a void located in a floor or road paving where an open space presents a fall hazard.
This topic includes information related to metal gratings installed during construction. Metal gratings are floors with repetitive, open spaces. Metal gratings have a bar or plank design that is commonly made from steel or aluminum materials. Metal gratings are welded, forged or riveted.
Metal railing systems are a typical feature of design elements such as stairs, ramps, drop-offs and uneven walkways. Metal railings utilize the same basic structural components as wood railings: a top handrail; a bottom rail or track; balusters or newel posts for main load transfer to the walking surface; and infill panels, pickets or spindles. While the design of railing systems must meet stringent code requirements for safety and structural support, metal railing systems offer a broad range of design options from a basic picket rail to an industrial wire mesh panel to custom artistic designs. The structural capacity, durability, and ease of fabrication of metal railing systems provide some advantage over wood railings, but they are generally more expensive.
This topic includes information related to catwalks installed during construction. Catwalks are narrow elevated walkways with railings and handrails, which allow building personnel to reach difficult locations or pedestrians to cross difficult terrain. Catwalks are commonly located in theaters, above stages, between portions of a building, along the side of large industrial tanks and as part of pedestrian bridges.
Metal stairs are an important component of most multi-story buildings and provide a variety of design options. Typical design configurations are straight run, L-shaped, and switch-back. Spiral stair systems fabricated from metal components are also common and offer many design options. A metal stair system can be designed as a multi-story self-supporting structural unit, independent of the building structure, or as a single flight of stairs that is structurally supported at each floor or landing. One of the biggest benefits of a self-supporting stair system is that it can be installed independently of the floor structure. More commonly, stair systems are designed in single flight segments and require structural support through a connection to a floor structure or vertical columns. Metal stair systems are fabricated at a metal shop or facility based on job-specific shop drawings and are delivered to the site in segments to facilitate erection.
This topic includes information related to metal fabrications installed during construction. Metal fabrications are manufactured, standard metal shapes, plates, grates and specialties. Metal fabrications are commonly used in the construction of stairs, railings, floors, enclosures and other assemblies. Fabrications can be made from steel, cast iron, cast aluminum, aluminum alloy or stainless steel.