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Co-engineering helps DACHPOLL ensure roofing tiles respect updated Euronorm

Steel roofing and cladding materials are among the most cost-efficient solutions available on the construction market today. As well as being light and easy to handle, these products are quick to assemble. And they are available in a wide range of shapes and colours to suit almost any built environment. With a new Euronorm (EN 508-1) for self-supporting roofing and cladding sheets that came into force in October 2021, ArcelorMittal Europe – Flat Products has been helping the makers of profiling machines to ensure their systems meet the new standard. DACHPOLL, a leading manufacturer of profiling machines, has co-engineered with ArcelorMittal to ensure the roofing tiles produced on their machines meet the new standard, particularly in regard to the minimum bending radius.

DACHPOLL has been active in the profiling market for over three decades. Around 12 years ago the company began to produce its own profiling machines for roofing tiles, trapezoidal sheets, and roof accessories at its facility in Poland.

“The shaping of steel tiles is quite a challenge,” notes Daniel Drozdowski, Production Director for DACHPOLL. “Until now it has been difficult for roofing tile producers to design and manufacture shapes that respect the limitations of the substrate, and which do not have defects such as wrinkling.”

New bending requirements

The publication of the updated Euronorm for roofing and cladding products introduced a new mandatory requirement on bending. Steel roofing and cladding materials must now observe a minimum internal forming radius that is at least twice the thickness of the material. If this minimum is not respected, the paint and metallic coating layers of roofing and cladding products can crack, reducing the lifetime of the application.

“In 2019, DACHPOLL started working with ArcelorMittal to ensure our profiling machines use the appropriate radii during profiling and stamping operations,” says Michał Brewka, DACHPOLL’s Commercial Director. “It is particularly important that the minimum radius is not exceeded on the ridge of the tiles. Otherwise the paint layer can crack during the forming operation. This weakens the integrity of a roof as it allows humidity to penetrate and corrode the metallic coating – and then the steel core. In extreme cases this can lead to premature perforation of the roof.”

DACHPOLL’s profiling machines can create tiles in a range of different shapes 

Tiny adjustments invisible to end user

During the co-engineering project, ArcelorMittal tested roofing tiles where rust had appeared prematurely. “ArcelorMittal’s R&D team found that many profiling machine customers were exceeding the minimum bend radius specified in our documentation,” says Daniel Drozdowski. “Tiny adjustments to the design of the final product can make a big difference, and they are not noticeable to the end-user.”

“Thanks to the cooperation between ArcelorMittal and DACHPOLL, we can assure customers that they can profile strips correctly for roofing and cladding applications,” says Michał Brewka. “DACHPOLL has also gained additional experience which allowed us to find a compromise between the expectations of roofing tile consumers for aesthetic shapes and designs, and the processability of materials such as ArcelorMittal’s Granite® Ultramat and Granite® Storm organic coated steels. We expect that the changes will dramatically reduce the number of complaints we receive.”

“It may seem unusual for a steelmaker such as ArcelorMittal to take on a project like this,” notes Paweł Patyk, Head of ArcelorMittal’s Technical Client Team for Region East. “But we believe that we must take responsibility for ensuring consumers can enjoy undisturbed use of their new roof for the long-term.”

DACHPOLL is also producer of steel roofing and facade systems, and its roofing solutions are often made with ArcelorMittal’s Granite® range of organic coated steels 

Granite® Ultramat: safe for 20 years and more

Granite® Ultramat is part of ArcelorMittal’s Granite® range of organic coated steels for outdoor building applications.

  • Designed specifically for roofing.
  • Advantages over standard Granite® Deep Mat and competing products thanks to the high quality and flexibility of the paint system used.
  • Wrinkled finish, available in 11 colours.
  • Good formability at low temperature and after cold storage.
  • Improved scratch resistance.
  • ArcelorMittal Europe – Flat Products offers guarantees of up to 20 years on non-perforation and up to 15 years for non-delamination. Granite® Ultramat’s aesthetic properties are guaranteed for up to 10 years.
  Technical data sheet


Related links

Everything you want to know about ArcelorMittal’s Granite® Ultramat
Order your Granite® Ultramat steel samples here
More info on the Granite® range
Discover our roofing configurator (Polish version)
Contact ArcelorMittal Europe – Flat Products
Steel for construction at


In addition to profiling machines, DACHPOLL makes cut-to-length lines


Banner is © Jerzy Wawrzyczek

Copyright other images: Dachpoll and ArcelorMittal