Putting Granite® HDS organic coated steel in architects’ hands results in a new look for a waste and energy plant

Detailed information

The Sittomat plant in Toulon, France generates steam and energy from household rubbish, providing electricity and heating to the nearby community. In July 2013, the plant’s owners decided to replace the existing zinc roof and facade cladding which was aging rapidly due to the local marine environment.

In May 2015, ArcelorMittal Europe – Flat Products presented its Steel Envelope, our showcase of aesthetic steels for construction, to the director of Vinci, Pierre Bourgoin, and his team. Vinci was the company responsible for the renovation of the Sittomat plant.

During the meeting, the ArcelorMittal team demonstrated our innovative steel solutions for roofs and facades. Following a discussion about the Sittomat plant, Vinci expressed an interest in realising the 8000 square metre roof of the Sittomat plant in Granite® HDS. The original plan was to fabricate the roof in zinc. Offered with a double-sided 35 micron organic coating, Granite® HDS was a perfect solution for the industrial site and marine location.

Strength and coating make Granite® HDS the right choice

While Granite® HDS was not his initial choice of material, the architect was quickly convinced by the steel’s thick paint coating which includes a 15 micron primer and 20 micron top coat. Granite® HDS was lighter and much more cost effective than zinc. The use of Granite® HDS allowed Vinci to realise the architect’s detailed curved roof design thanks to its double-sided coating and strength.

Granite® HDS offers very good corrosion and UV resistance as it is designed for use in cladding and roofing applications. It is also easy to form. As part of ArcelorMittal’s Nature range, all Granite® products are free of hexavalent chromium and heavy metals. “I was surprised and pleased that Granite® HDS from ArcelorMittal could be the answer for such a curved roof, which I originally imagined in another material,” said Thomas Fogacci from FOGACCI + FOGACCI ARCHITECTES who designed the renovation to the Sittomat plant.

Short timeframe, quick response

In June 2015, Vinci (who is usually our customer’s customer) placed an order directly with ArcelorMittal for 80 tonnes of Granite® HDS, with first deliveries required in July. Due to the tight timeframe for the project, 2.5 tonnes of the Granite® HDS coils were delivered from ArcelorMittal Atlantique and Lorraine (in Montataire, France) to the Sittomat plant in Toulon. This was the first time ArcelorMittal Europe – Flat Products had had to deliver material straight to a construction site. Once onsite, the coils were converted to roof profiles in an innovative mobile unit operated by a sub-contractor to Triverio Construction.

By using the portable profiling unit, the project team saved valuable time and money as there was no need to use a specialised profiler. Panels could be erected just after profiling, allowing Vinci to closely control the quality and technical aspects of the profiles. This was particularly important due to the curved shape of the roof. The environmental impact of the project was also lowered as the Granite® HDS did not need to be sent to Triverio’s plant in Italy for processing and then back to Toulon.

Flexibility to change

The high complexity of the project and the innovative design meant a number of changes were made to the order during construction. These changes required flexibility from ArcelorMittal’s entire organisation. For example, in June the client requested that the steel be protected with a self-adhesive temporary film during the profiling process. In July, the width specifications changed. The specifications of the order, tight timeframe, and late changes involved ArcelorMittal personnel from the mill, order administration, our French commercial agency, logistics, and profiling partners. The customer was extremely pleased with ArcelorMittal’s quick response times, flexibility, sharp price, product quality, and the overall handling of the order. “ArcelorMittal demonstrated leadership and closely monitored our specific needs – especially in terms of delivery time, flexibility, and product quality,” noted Yann Lambert, manager of the Sittomat project for Vinci.

Final deliveries of steel were made by ArcelorMittal in late September 2015. Work on the roof and facade of the Sittomat plant was finished by November, in time for winter. The traditional panels for the building’s facade were processed and delivered by our customer Bacacier.