Detlef Strauch, Secretary-General of the International Federation for the Roofing Trade, presented Estonian construction companies' group Nordecon the award for its construction of the best metal roof in the world – that of the Ahhaa Science Center, Nordecon said in a statement.
The Ahhaa Science Center boasts some unusual geometry: a dome and semi-dome with laminated timber arches 35 meters 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 two-three centimetres 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 meters in diameter, is a three-dimensional steel 'ball'. The material covering the sphere is Rheinzink, which is not widely used.
Image: Tekla
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Museums as a Mirror of Society - interpretation
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