Environmental Classes
Selection of the material and the surface coating depends on the particular project, the node and the environment (it is worth noting whether there is a desire to use the product in a situation where it is completely open to the weather, covered or sealed from direct precipitation and in a dry environment).
In assessing the need for use (required resistance to corrosion) and the environment in which the product is used, a choice can be made of the product which corrosion resistance and the surface coating would be most sensible to use.
In most of the ACF sheet metal products has been used steel DX51D with a zinc coating Z275 (275 g/m2).
There is also a range of products, to which has been attached a layer of paint, they have been post/galvanized or are made of stainless steel. The corrosion resistance of this product is even greater.
(EN ISO 12944-2)
| Class | Zinc layer mass decrease g/m2 | Zinc thickness loss micron/year | Description of environmental conditions |
|---|---|---|---|
| C1 | less than 0.7 | less than 0.1 | Pure air-heated buildings. Offices, schools, shops, etc. |
| C2 | 0,7...5 | 0,1…0,7 | Regions with low air pollution. Cold buildings, gyms and places where condensation may occur. |
| C3 | 5...15 | 0,7…2,1 | Urban areas with medium air pollution, coastal areas with low salt content, production facilities, laundry facilities, etc. |
| C4 | 15...30 | 2,1…4,2 | Coastal areas, industrial areas with high air pollution. Chemical plants, swimming pools |
| C5-I | 30...60 | 4,2…8,4 | Coastal and industrial areas with a very high humidity and aggressive environment. Buildings with continuous water vapor and condensate. |
| C5-M | 30...60 | 4,2…8,4 | Environments with a very high salt content, aggressive industrial area. |
Wearing of the thickness of the zinc layer life cycle in class C3 *:
*) C3 is a more common in the environmental condition in Estonia
| zinc layer mass g/m2 | The average thickness of the zinc layer in microns (um) | life expectancy; years | |||||
|---|---|---|---|---|---|---|---|
| 100 | 7 | 3…10 | |||||
| 140 | 10 | 5…14 | |||||
| 200 | 15 | 7…21 | |||||
| 225 | 16 | 8…22 | |||||
| 275 | 20 | 9…28 | |||||
| 350 | 25 | 12…36 |
The amount of the zinc layer g/m2 indicates the total amount of zinc on each side of the 1 m2 surface area.
Other factors affecting the life of galvanized steel:
- Climate
- Corrosion (mechanical or organic)
- Thermal and hydraulic calculations
- Mechanical stress