Exposure class C1: Very mild
Dry indoor spaces.
Approved roofing screw
Although a sheet metal roofing screw may seem like a small detail, it plays a significant role in the durability of the entire sheet metal roof. For a sheet metal roof to last, choose a roofing screw that complies with regulations.
The only painted roofing screw approved for outdoor use
The design and manufacture of the KINGI® roofing screw start from the laws, regulations, requirements and guidelines that apply to this product. Anyone choosing a KINGI® roofing screw can be confident the choice is safe and compliant.
The KINGI® roofing screw is the only painted carbon steel screw to have been granted ETA approval (ETA-25/0267) for climate exposure classes C1–C4. It has been tested to withstand the demanding C4 class, as shown in the HAMK statement (PDF, opens in a new tab). This means Kingi is suitable for use practically anywhere in Finland.
Read more about Kingi’s properties.
Approved roofing screw in Europe
Currently, the only harmonised and comparable European method of demonstrating the suitability of a roofing screw for outdoor use and corrosion classes C2–C4 is an ETA assessment based on document EAD 330046-02-0602.
Intended use
It is the builder’s responsibility to choose building materials that are suitable for the intended use. According to the regulations, a steel roof must therefore be fastened with roofing screws, not, for example, drywall screws. The manufacturer’s statement of intended use may sometimes be misleading. So be careful when choosing building materials for your roof renovation.
Service life
Building industry standards define indicative service lives for different types of buildings and building components. The roofing screw should last as long as the building, which means a durability requirement of 50 years for a detached house.
Climate exposure
Climate exposure wears down all building materials. The amount is affected by emissions from traffic and factories, temperature and humidity. The roofing screw complies with regulations and a metal roof will last when you choose a roofing screw suitable for the climate exposure at the building site.
Corrosion resistance
The secret of durable construction lies in the fact that all parts of the structure are able to withstand ageing for equally long. The coating screw must therefore last just as long as the roofing sheet. Although one might think that all coating screws withstand rusting for as long as the roofing sheet, this is not the case.
Exposure class C2: Mild
Unheated indoor spaces, dry and clean outdoor air, and a rural environment.
Corrosivity category C3: Moderate
Urban and industrial atmosphere with moderate sulfur dioxide pollution. Coastal areas with low salinity. Indoors, production facilities with high humidity and air pollution.
Corrosivity category C4: High
Outdoors, industrial areas and coastal areas with moderate salt content. Shipyards on the coast. Indoors, chemical industry production facilities, swimming halls and pools.
| C1 | C2 | C3 | C4 | |
|---|---|---|---|---|
| KINGI® roofing screw | ✓ | ✓ | ✓ | ✓ |
| Roofing screws from other manufacturers with a verified declaration of performance | ✓ | ✓ | ✗ | ✗ |
| Roofing screws from other manufacturers with a CE mark | ✓ | ✗ | ✗ | ✗ |
Ask Kingi
What factors affect the durability of a sheet metal roof? Why is the KINGI® roofing screw not made of stainless steel? You will find answers to these and many other questions in the Ask Kingi column. If you cannot find an answer, you can also ask Kingi yourself.
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The Kingin newsletter always contains current and interesting information about steel roofing, its durability and durable fastening. The newsletters also provide information about construction, building regulations, construction products and their approval. When you subscribe to the Kingin newsletter, you receive tips that help you build more durably and cost-effectively.