You have to consider many factors when designing an architectural project in order to ensure quality and value. The construction technique is in most cases the first item to be evaluated, because it is the one factor that properly materializes the proposed design and determines the efficiency of the project in terms of time, costs, labor, finishes and final quality.
The construction sector is responsible for producing a large amount of waste. According to Elcio Carelli, economist and master of environmental technology, 60% of the total waste produced in Brazilian cities comes from civil construction [1]. Diana Scillag, director of the Brazilian Council of Sustainable Construction (CBCS), found that while only 20% to 50% of natural goods are actually consumed by the sector, the urban solid waste generated double this number [2].
In addition to wasting resources, traditional construction systems, such as masonry and concrete, demand a greater amount of time compared to other industrialized systems which are prefabricated. Thinking about alternatives capable of adapting to different territories, which are cost-effecient and fast to implement, has become a priority among architects and builders.
Using prefabricated materials in an assembly system eliminates the use of cement and will allow you to nail down the construction of a work in a short period of time. There are two main models: a Steel Frame and a Wood Frame.
Skeletons made of steel or wood profiles build lightweight frames, which then lift up the elements that make up the spaces, such as the walls. Contrary to what happens with ceramic or concrete blocks, the frames are closed externally by cement boards, and internally by plasterboards, which subsequently receive other coatings (paint, wallpaper, etc.). Special membranes are strategically placed between the layers of the "sandwich" for thermal-acoustic treatment.
The Steel Frame system is widely distributed in European countries. It has been mass produced with specific dimensions and spacing to be coupled with industrially produced profiles and joints. It is important to note that according to the region in which the project is located, the steel used may vary in thickness and type, derived from the areas (coastal, rural, urban). Normally the uprights have maximum spacings in axis of about 600mm and in the case of hydraulic walls, about 400mm [3]. In roofs, the metal structure commonly receives corrugated or fiber cement tiles. Due to the modular spacing regulated between the uprights, the openings (doors and windows) must be strategically arranged and designed together with the technical development of the project.
As a quick and clean work, this system presents many advantages. Its versatility stands out as it can be used in buildings of up to four storeys and in commercial projects. Another important point is the possibility of recycling steel.
The Timber Frame system is a very widespread system in the American territory. It has low energy consumption during processing, is made from renewable sources and has a high resistance to loads. Most often, structural calculations are made to find the correct dimensions of the wood profiles and position them to form a square. Subsequently, OSB wood plates are put together with cement board and a cladding to form the wall. Internally, membranes are included to reinforce thermal and acoustic insulation.
A series of strategic perforations are arranged to allow for electrical installations. It is important to emphasize that this system is as resistant as the masonry walls and lasts about 100 years.
Finally, we must bear in mind that more and more cities will have to meet the demands of construction by developing techniques capable of uniting quality and sustainability, economic efficiency and mass production. The dry construction systems (Steel frame and Timber Frame) can provide the above benefits and are great examples of systems we would want to consider using in the future.
Notes
[1] CARELLI in Aecweb.
[2] SCILLAG in Aecweb.
[3] DA SILVA, 2013.
Bibliographic References
- DA SILVA, Fernanda Benigno. Sistema construtivo a seco - Light Steel Frame. Available at: < http://techne17.pini.com.br/engenharia-civil/195/sistema-construtivo-a-seco-light-steel-frame-294078-1.aspx>. Viewed on 03 Mar 2018.
- Os verdadeiros impactos da construção civil. Available at: https://www.aecweb.com.br/cont/n/os-verdadeiros-impactos-da-construcao-civil_2206. Viwed on 03 Mar 2018.