What phenolic resins can do

The material for the breath-taking interior of the new Concert Hall in Katowice was supplied by Koskisen, the Finnish firm of wood makers. Products from Prefere Resins also played their part – And the musicians and public are thrilled.

“Both atmospherically and acoustically, this hall is unbelievable.” Speaking on Bavarian Radio, Alexander Liebreich, conductor-in-chief of the Polish National Radio Symphony Orchestra, was full of praise for his new workplace, the Concert Hall in the Polish city of Katowice, on the occasion of its inauguration in October 2014. The striking visual impression, a combination of anthracite and warm brown shades throughout, is branded in particular by the shimmering colours of birch plywood. It was supplied by the Finnish wood specialist Koskisen, the breath-taking material being all held together by phenolic resins from Prefere Resins.

The balconies, together with a round ceiling structure of 16 metres diameter, are the key elements of the hall and were supplied by Koskisen for the Polish construction company Warbud. The first prototypes for the balcony elements were on site in spring 2011, while the final phase only started at the end of 2013. But good things are worth the wait. And work could not have progressed much faster anyway, as the demands made by the structural design were enormous. The round ceiling section in particular was a real challenge for Koskinen – and the Finnish wood specialists are used to quite a lot. But the ceiling structure was all about nuances. “Ensuring that the different shades of wood all go together was extremely challenging,” says Anna-Maaret Roppola, project manager at Koskisen for the interior fittings of the Concert Hall. And it was a challenge that also applied to Koskisen’s own suppliers, among them Prefere Resins. After all, it is Prefere’s phenolic resins that hold “BirchUp”, the Koskisen product from which much of the interior of the Concert Hall is made, together.

However, “BirchUp” is no ordinary glued birch wood product. In BirchUp, strips of plywood are combined with slats of solid wood, and it is this that creates the special colour combinations which, together with the anthracite-coloured interior walls, give the auditorium of the Concert Hall its special fascination. The use of this material was preceded by an extensive testing phase, for as Roppola says, Koskisen “always strives to bring together the best possible product characteristics for our material. Our goal is, in the best case, to even exceed the end-customer’s expectations.” With over 15 years’ experience with BirchUp and other special plywood products, Koskisen was the perfect partner for the interior of the Concert Hall. Each part was prefabricated in Finland and then transported to Katowice, where it was then seamlessly re-assembled. The idea for the interior colour scheme of dark walls and paler shades of birch wood came from the Polish architect, Tomasz Konior. He first came across birch wood on a simple Finnish sailing boat and succumbed to the fascination of the material. Together with the planners at the renowned, internationally operating Nagata Acoustics company, the idea of the special woods was born, which were then produced specifically for the new Concert Hall and its acoustic and visual requirements.

Roppola: ”We worked in very close collaboration with our suppliers on this project in order to meet the high demands.” One thing of particular importance was the bond between the plywood and the solid timber slats. “The top-quality phenolic resins from Prefere have outstanding properties – and in this project, as always, Prefere made its vast experience available in finding the best product and the right solution. As a living material, our wood needed phenolic resins that create a good bond but are still sufficiently elastic.” So, the wood and resin made an ideal match – for the biggest use of BirchUp that Koskisen has carried out to date.

The outcome is a world-class concert venue – built on the site of a former coal mine. In a way, the colours of wood and anthracite to be found inside the building are a continuation of this, as they reflect the traditional canon of materials associated with underground mine workings. However, there is naturally no longer the noise of picks and shovels to be heard, but the harmonious sounds of an aspiring orchestra. As Susanne Vongries, the choir manager of Bavarian Radio, put it, speaking on the radio on the occasion of the inauguration: the hall is “visually and acoustically an absolute highlight.” And she should know: “After all, we are familiar with all the concert halls in Europe and beyond.”

But the interior of the new Concert Hall does perhaps have one thing in common with the tunnels in a coal mine: they both need enormous strength so that nothing can come down. After all, lives depend on it.