Ecological evaluation of sheathing component selection in light gauge steel construction method

The light gauge steel construction method is distinguished from other construction technologies as a durable and fast solution, especially in disaster areas, with its resistance to earthquakes. Although the history of structures produced with light gauge steel materials in the world dates back to the nineteenth century, their use began to become widespread in our country after the 1999 Gölcük earthquake. Light gauge steel structures were handled as a separate section for the first time in Turkey's Building Earthquake Regulation, which came into force in 2019. However, the preference of traditional construction methods as a reliable solution shows that the recognition of light gauge steel structures, which is considered as a new construction technology for our country, has not reached a sufficient level. Light gauge steel is a ductile material and suitable for modular construction system. Since it is a dry method of construction it can be built independent of weather conditions. It has relatively short construction time compared to other construction techniques and easy to install. Moreover, light gauge steel construction technique is a prefabricated construction system and have low superstructure weight, therefore it is a suitable construction method especially for earthquake zones. Although the light gauge steel construction method is widely used in low-rise buildings such as residences, it can also be used in industrial buildings and buildings with different functions such as hangars, warehouses, hospitals, schools, dormitories, restaurants and office buildings. Building products and the construction process used in the building industry can have negative effects on the environment. For this reason, ecological choices should be made as much as possible in the selection of building products to be used. Although the initial formation energy of light gauge steel material is high, it is an ecologically sustainable building product with features such as durability, reducing the damage to the environment with a short construction period, contributes to energy conservation with the possibility of recycling without losing its physical properties. Furthermore, light gauge steel construction method is not requiring heavy labor and construction machinery due to its light weight. It has low foundation cost and less concrete use. Since it is a prefabricated system, it has low material consumption. However, product selection for the whole building should be made by considering the positive and negative effects of not only the framework but also the complementary construction products accompanying the framework on the environment. Light steel structures consist of light steel skeleton, fittings, special bending parts, plumbing components, insulation components and sheathing components. This study includes the evaluation of the structural and facade sheathing components used for the cladding of the steel skeleton in the light steel construction method in terms of ecological criteria. While these sheathing components have an important place in the creation of the wall body of the light steel structure, the structural cladding component directly affects the design of the light steel frame. At the same time, sheathing components have an important place in the light steel construction method as they are used in stairs, flooring, roof and ceiling coverings, and facades. In this context, interviews were made with thirty companies that make light steel construction applications in our country and the most frequently used sheathing components were determined. These identified products are: oriented strand board, fiber-reinforced cement board, cemented particle board, gypsum board covered with fiberglass and gypsum board. Galvanized steel sheet plates can be preferred for industrial building exterior cladding. Apart from these products, plywood, brick veneer, natural stone veneer and metal-based facade claddings, which can be used in light steel construction method, were also evaluated within the scope of the study. These products have been evaluated in terms of resource/energy efficiency and internal/external environment throughout the life cycle of the product, including the pre-use period, the use period, and the post-use period. For this evaluation, raw material is obtained from local sources, use of renewable raw materials, contains recyclable raw materials, contains recycled raw materials, requires less water in production, energy efficiency in production, produced by local producers, does not contain harmful raw materials, low or zero emissions, less waste in production, long service life, low maintenance costs, thermal comfort, contribution to sound insulation, moisture balance protection, not adversely affecting air quality, less waste generation in repair, reusability, recyclability, less waste generation in demolition were used. After examining the sheathing components with their general properties, it was examined in terms of having the specified ecological criteria, having some of the criteria or not having it at all. Among the sample components examined, there is no product with all ecological criteria. As a result of the evaluation, each material has different ecological advantages and disadvantages; It has been observed that the effects of materials on the environment during the production phase can vary depending on the factory conditions where they are produced. In the evaluation made in terms of having all of the ecological criteria, gypsum boards are the components that meet the criteria most with their ecological characteristics close to each other. When evaluated in terms of having all or some of the criteria, cemented particle board, oriented strand board, fiber reinforced cement board, brick veneer, plywood board, stone veneer and galvanized sheet metal come after gypsum based boards.