Stonecon Ltd

Kohteen perustiedot

  • architect Alvar Aalto
  • real estate owner: Helsinki city
  • buiding works were completed in 1971
  • original facade cladding was made of Carrara Bianco marble
  • original facade was in very bad condition due to deterioration of marble
  • original marble was replaced by new Carrara Bianco marble
  • facade renovation was carried out during 1997-1999
  • building management: HKR-Rakennuttaja
  • architect: Kaarlo Leppänen
  • stone technology consulting: Stonecon Oy
  • stone contractor: Työyhteenliittymä AW Liljeberg-NCC Puolimatka Oy

Rakennusprojektin erikoispiirteet

  • preservation of Alvar Aalto cultural heritage was taken into account throughout the project
  • due to its cenral location Finlandia Hall plays an important role in Helsinki city architecture
  • process for choosing the material was long lasting and complicated
  • choosing again marble as replacement for the original facade was based on legal protection clausule
  • measures of stone panels were reduced with 20 % in both dimensions and thickness of stone panels was locally increased
  • thermal insulation and fixings were completely redesigned
  • special attention was given to quality control of marble during the project
  • panels of the new facade started bowing soon after being installed and bowing continues to increase
  • building was normally in use during the renovation project
  • total area of restored stone cladding was 6800 m2

MARA-tutkimusprojekti

  • EU research project, which was executed by Helsinki city during 1999-2001
  • goal was to determine reasons for bowing of marble and develop a reliable method for testing suitability of marble for outdoor applications
  • background for MARA was the lacking knowledge of marble durability properties, which was notified during Finlandia Hall facade renovation
  • received funding from EU program Rafael, which is directed to preserving the valuable European cultural heritage
  • research institutes and stone companies from Finland, Italy and Portugal participated as collaborators in the project
  • extensive laboratory testing for different marble qualities from Italy and Portugal was carried out
  • several earlier building objects, where marble had been used, were examined
  • it could be proved that deterioration and bowing of marble is due to internal structural cracking of the material
  • clear correlation was found between crystalline structure of marble and its sensitivity to deterioration
  • it could be shown that different types of marble have substantial differences in durability properties
  • influencing factors were clearly dtected, but reliable methods for testing durability properties of a specific marble could, however, not be developed
  • large amount of knowledge about marble durability properties was produced based on both laboratory testing and empiric research of earlier references
  • reserach manager of MARA -project was MD Pekka Mesimäki (M.Sc. Civil)/ Stonecon Oy