OREANDA-NEWS. April 16, 2012. At the Eesti Ehitab 2012 trade fair today, Detlef Strauch, Secretary-General of the International Federation for the Roofing Trade, presented Nordecon AS with the award for its construction of the best metal roof in the world – that of the Ahhaa Science Centre.

The roof was designed by architects Ain Padrik and Vilen Kunnapu and constructed by DMT Insenerid, led by project manager Peeter Voovere.

“I visited the centre myself as part of my trip here to Estonia and all I can say is that the award is very much deserved – construction of the roof was clearly of the highest quality,” Strauch said. “Many thanks to Nordecon for doing such a good job of it!”

Strauch says the management board of the IDF was surprised by the number of entries received for the competition and the variety of countries from which they were submitted, and that the jury of independent experts had a tough time deciding on the winners.

The Ahhaa Science Centre boasts some unusual geometry: a dome and semi-dome with laminated timber arches 35 metres in diameter; a sphere with a bowl-shaped reinforced concrete base supported by three concrete columns and featuring the glass floor of the planetarium; and a curved gallery connecting the dome in the air. Moreover, all of the roofing elements employ materials that have rarely or never been used before in Estonia – KalZip aluminium profiled sheets on the dome and semi-dome and Rheinzink titanium zinc sheeting panels on the sphere.

The underlying constructions of the dome and semi-dome are load-bearing laminated timber beams and the sheathing boards affixed to them. The non-ventilating roofing system of the domes is the first of its kind in the Baltic States, comprising a vapour barrier glued to the sheathing board base, the counter-girders attached to it, heat-insulating wool and the aluminium profiled sheets forming the covering layer. What makes this design so unusual is that the wool used as the insulation material is compressed by 2-3 cm when the aluminium profiled sheeting is installed, and that no underlying cover or ventilation beneath the roofing cover was constructed. The panes are machine-rolled lengthways, while across they are welded together. All of the material was pre-fabricated to fit the geometry of the roof by KalZip GmbH.

The underlying construction of the planetarium’s sphere, which is 11 metres in diameter, is a three-dimensional steel ‘ball’. The material covering the sphere is Rheinzink, which is not widely used. Different-sized diamonds form each row of the roof cover as sheeting panels – a roofing solution that is rarely seen. The material covering the gallery connecting the planetarium’s dome is S-wave aluminium profiled sheeting.

Nordecon’s partners in the construction of the Ahhaa Science Centre were DMT Insenerid OU, Arhitektuuriburoo Kьnnapu & Padrik, Peetri Puit OU, SGA Production OU, KalZip GmbH,  Okomehed OU, Parmet AS and Tallinna Linnaehituse AS.