In this blog post, we’ll take a simple look at what gang formwork—commonly seen at apartment construction sites—is, what role formwork plays, the background behind the emergence of gang formwork and its structural features, and what significance it holds at construction sites today.
If you’re from South Korea, you’ve probably passed by an apartment construction site at least once in your life. If you noticed something encircling the very top of the apartment under construction, it was most likely a gang form. A gang form is a large formwork system used to construct the exterior walls of multi-story concrete structures, such as apartment buildings, and it is typically integrated with work platforms and safety features. Even today, gang formwork is classified as a type of integrated formwork system with a work platform used on construction sites, and it is worth exploring its role, origins, and significance.
When constructing buildings, many structures are made of reinforced concrete, and the primary material used in these structures is concrete. Immediately after pouring, concrete has difficulty maintaining its desired shape on its own; it develops strength as it hardens over time. Formwork is essential to ensure that the concrete hardens into the desired shape. Before it hardens, concrete is like mud—it cannot hold its shape on its own and may flow out of the mold. Therefore, a mold is needed to contain the concrete so that it can maintain a specific shape until it hardens into the designed form and develops sufficient strength. Formwork serves precisely this purpose. In other words, formwork is a structural system that supports and maintains the shape of concrete—such as columns, walls, and floors that form the structural framework of a building—so that it can harden into the form intended by the designer. Generally, formwork can be understood as a single system that includes not only the surfaces in direct contact with the concrete but also the supporting members and connecting and reinforcing elements.
Formwork has evolved alongside advancements in construction technology, leading to the development of various types tailored to the characteristics of the structures being built. A prime example is the gang form. A gang form is a large, movable formwork system used to construct the exterior walls of multi-story concrete structures, such as apartment buildings and office towers. It is particularly efficient for exterior wall construction in multi-unit residential buildings, where multiple floors must be constructed repeatedly, as the large formwork assembly can be moved to the next floor and reused repeatedly. To accurately understand gang form, it is first necessary to examine the characteristics of apartment structures. In multi-unit residential buildings, wall-bearing structures—in which the walls structurally bear the building’s load and external forces—are widely used. In this case, apartment walls are composed of rebar and concrete, and in apartment buildings with repetitive floor plans, the exterior walls of multiple floors are often constructed in a similar manner. Furthermore, when considering a single floor, the edges facing the exterior are typically composed of exterior walls. Due to these structural and construction characteristics of apartment buildings, gang formwork—which allows multiple formwork units to be bundled together and moved repeatedly—has been utilized. In practice, gang formwork is used by moving it to the next construction location with lifting equipment, such as a tower crane, to sequentially construct the exterior walls of multi-story concrete structures.
Conventional formwork involves connecting multiple thin, wide rectangular panels made of aluminum, steel, or wood to create a frame of the desired shape, into which concrete is poured before it hardens. In concrete construction, when work on a given floor is completed and construction begins on the floor directly above, the formwork used on the lower floor can be reused. The process of reusing formwork involves workers first installing the formwork by tightly connecting each panel to create a frame. Then, once the concrete inside the frame has sufficiently hardened, workers manually remove each formwork panel one by one. Typically, individual form panels are small enough and light enough for one or two workers to handle; however, in cases such as apartment construction—where the same or similar tasks are repeated across multiple floors—workers must manually repeat this process dozens of times. To work efficiently and quickly, and to minimize errors that can occur during manual assembly and disassembly, gang formwork began to be utilized and has since become widely used on construction sites. Gang formwork consists of multiple formwork panels assembled into a single large formwork unit. When moving the formwork to the next floor for construction, rather than having workers carry the panels one by one, the assembled large formwork unit is lifted by a crane or other lifting equipment and moved to the next construction location without being disassembled. In practice, gang formwork is often configured as an integrated unit comprising large steel formwork, a frame, a cage that allows workers to operate from the outside, and work platforms.
Furthermore, gang form systems often include work platforms assembled directly onto the formwork assembly to facilitate concrete-related tasks. When performing concrete work, the concrete surface may not be smooth after the formwork is removed once the concrete has set. In such cases, workers must grind down any protruding areas or fill in any small holes or indentations. In particular, when working on the exterior walls of a building—that is, the walls facing the outside and visible from the street—workers must operate at heights, making dedicated work spaces and safety equipment essential. Using the work platforms and safety equipment installed on gang forms allows for more efficient execution of such exterior wall work. Currently, under South Korea’s construction safety management system, formwork systems with integrated work platforms—such as gang form—are classified as major temporary structures and are subject to the requirement to establish a safety management plan if certain conditions are met.
Due to these characteristics, gang formwork serves several important purposes on construction sites. The first is efficiency. Utilizing gang formwork reduces repetitive formwork installation and dismantling tasks and allows large formwork units to be moved all at once, which can help shorten the construction schedule. In the construction industry, shortening the construction schedule is of utmost importance. In particular, large-scale construction projects, such as apartment complexes, have long construction periods and require significant manpower, equipment, and materials; therefore, efficient management of the construction schedule has a major impact on overall construction costs and productivity. Consequently, streamlining repetitive tasks through mechanization and minimizing errors that may occur during the work process are critical challenges on construction sites.
The second factor is safety. Construction sites can be hazardous work environments, as they often involve working at heights or handling heavy materials and equipment. Consequently, it is crucial to prevent various risks at construction sites, such as worker falls, falling objects, and the overturning or collapse of formwork. Using gang form allows for the integration of formwork, work platforms, and safety railings, which helps secure a safe workspace for exterior wall construction. However, gang formwork itself does not automatically guarantee safety. The formwork must be properly installed, supported, and reinforced to withstand the designed loads, and dismantling must only take place after the concrete has achieved sufficient strength. Therefore, even when using gang formwork, safety management is required throughout the entire process—from design and installation to hoisting, securing, and dismantling.
The third benefit is the reduction of noise and improvement of the work environment. During formwork operations, the repeated attachment and removal of heavy aluminum or steel panels can generate significant noise. This is a particularly important management issue for construction projects in urban areas, as noise directly impacts the living environment of nearby residents. Since gang formwork consists of multiple formwork panels assembled into a single large unit that is moved repeatedly, it helps reduce the need to install and dismantle individual panels each time. Furthermore, depending on the gang formwork’s structure, it is possible to design the system to incorporate panels or structures that enclose the work area, thereby reducing noise generated during work and minimizing its impact on the outside environment. In fact, various structures have been developed in gang formwork technology with the aim of protecting workers from the external environment and reducing noise generated during work.
Gang formwork technology is also constantly evolving rather than remaining static. While the focus in the past was primarily on assembling large formwork units and moving them with cranes, various gang formwork structures and auxiliary devices have since been developed to enhance worker safety and improve the efficiency of exterior wall work. Recently, systems that integrate work platforms and safety features have gained significant attention as a means to enhance safety and productivity at construction sites, and gang formwork is also being improved in line with this trend. Furthermore, South Korea’s construction policies are moving toward increasing the productivity of the construction industry by demonstrating smart construction technologies that utilize artificial intelligence and digital technologies and by fostering an ecosystem for these technologies. In other words, it can be seen that existing construction technologies are continuously improving not only through structural advancements in gang formwork itself but also within the broader context of construction site digitization and strengthened safety management.
To summarize the points discussed above, gang formwork is a type of formwork that integrates and scales up multiple formwork panels, work platforms, and safety features to efficiently perform repetitive formwork tasks. Since gang formwork can be moved to the next floor without being dismantled, it helps improve the efficiency of repetitive exterior wall construction on apartment buildings and shorten construction schedules. Furthermore, by integrating work platforms and safety features, it facilitates more systematic execution of work on exterior walls. Of course, gang formwork can only function properly when supported by appropriate design, installation, hoisting and securing, dismantling, and safety management. Ultimately, gang formwork is more than just formwork that allows concrete to set in the desired shape; it is a construction technology that has evolved to efficiently perform repetitive construction tasks and improve the work environment.
