For buildings whose structures are exposed to environments with increased aggressiveness, it is necessary to use sandwich panels, ventilated facades, load-bearing sheets and other products made of thin-sheet steel with high corrosion resistance.
The DSTU ISO 12944-2 standard describes six categories of corrosion activity, which are determined by the conditions of the external or internal environment. For the medium, high and extreme categories, it is recommended that materials and coatings for envelope structures be selected individually, considering all factors of influence and operating conditions, as this ultimately determines their durability.
Atmospheric corrosivity categories and examples of typical environments according to DSTU ISO 12944-2
|Corrosion aggressivity category||The attachments of typical environments|
|Outside the premises||Inside the premises|
|–||Heated buildings with clean air, e.g. offices, shops, schools, hotels|
|Low-pollution environment: primarily rural areas||Unheated buildings where condensation can occur, e.g. warehouses, sports halls|
|Urban and industrial environment, moderate sulphur dioxide pollution; coastal areas with low salinity||Industrial premises with high humidity and certain air pollution, such as food processing plants, laundries, breweries, dairies|
|Industrial areas and coastal areas with moderate salinity||Chemical plants, swimming pools, coastal vessels and shipyards|
|Industrial areas with high humidity and aggressive environment, as well as coastal areas with high salinity||Buildings or areas with almost constant condensation and high air pollution|
|Offshore areas with high salinity; industrial areas with extremely high humidity and corrosive environments, as well as subtropical and tropical environments||Industrial areas with extremely high humidity and aggressive atmospheres|
For example, in very aggressive environments, the incorrect choice of the type and thickness of the polymer coating of the sandwich panel cladding can lead to through corrosion and their destruction after several years of operation.
To select durable materials from light gauge steel, it is necessary to contact a qualified supplier at the design stage of the enclosure. The selection of envelope structures for use in aggressive environments is carried out individually and usually involves determining the characteristics of the environment, the optimal choice of materials and fasteners, and the development of structural joints.
At the beginning of the project, a questionnaire is filled out indicating the general characteristics of the building, technology features and known parameters of the external and internal environments, as well as the intended technological procedures.
If required, Rauta provides on-site surveys using modern measurement methods to determine the following parameters:
As a result, the client receives a report with detailed results of the environmental characteristics research.
After analyzing the results of the study, Rauta provides recommendations for the best protection of steel facades and roofs, indicating the following parameters:
To ensure the durability of a building, it is necessary to pay attention not only to the materials of the envelope structure, but also to the fasteners. The level of resistance of fasteners in aggressive environments should be no less than that of the structure coating.
|Corrosion aggressiveness category||Recommended fastener material|
|C1||Zinc-coated steel with a thickness of 8-12 µm|
|C2||Zinc-coated steel with a thickness of 8-12 µm|
|C3||Zinc-coated steel with a thickness of more than 45 microns, or ceramic-organic coating, or stainless steel A2 grade|
|C4||Stainless steel A2 grade|
|C5||Stainless steel A4 grade|
|CX||Stainless steel A4 grade|
The type of fastener is selected depending on the design features of the element connection.
The operation of steel facades and roofs in environments with increased aggressiveness imposes a number of requirements on structural joints, joint tightness, drainage, etc. Rauta specialists develop a detailed design of the necessary structural solutions, considering the technological features of the building (vibrations, electromagnetic loads, etc.) in such a way as to ensure the long-term operation of the facility, as well as high aesthetic and thermal properties of the envelope structures.
When Ruukki materials are supplied, the client is provided with a project warranty for the products under certain conditions of use. At the same time, the effective service life of the products is usually much longer than indicated in the warranty letter.
Rauta has extensive experience in supplying sandwich panels and ventilated facade cladding to facilities with increased environmental aggressiveness. Therefore, it can guarantee that the client will receive products that will meet the operating conditions in the best possible way. Upon delivery, Rauta additionally provides a full package of accompanying documents, including: recommendations for handling and operation, installation instructions, design solutions, load-bearing capacity calculations, etc.