Chapter 3 | The Building of Paimio SanatoriumB wing. The walls of the safe and the radiology department, which required exceptionally
strong structures, were cast in conjunction with the frame construction.^701
Sundeck parapets and the railing of certain staircases had been specified to be
made of rough-case concrete and were included in the frame construction. The stairs
were largely cast together with the rest of concrete construction, reinforced like slabs,
but some stairs were constructed as free-bearing structures, with steps made sepa-
rately. Staircases B (ward sister’s staircase) and C (ward staircase) in the patient wing
were cast in situ and covered with mosaic flooring plates.^702 In other words, Aalto
used prefabricated parts in these stairs.
The use of a reinforced concrete frame led to the use of hybrid structures, with the
different material layers in the wall serving a certain function. The purpose of the rein-
forced concrete was to bear load. Questions of heat and sound insulation qualities in
different structures were raised for discussion in professional journals during the early
1930s. The building report for Paimio Sanatorium recommended the use of expanded
cork, insulite or Celotex board in places where the concrete structures of the interme-
diate floor creates a thermal bridge.^703 On external walls, heat insulation was resolved
using redbrick and expanded cork, and with coke cinder in intermediate floor cavities.
The Paimio Sanatorium archives hold 28 structural drawings by Emil Henriks-
son and the set of drawings is incomplete. Emil Henriksson’s office archives were
destroyed in a fire that started by an incendiary bomb during World War II,^704 and
the Alvar Aalto Museum Archive holds no copies of Henriksson’s structural drawings.
The structural drawings contained markings indicating the person who made the
strength calculation and drawings, but some pictures lacked these markings. In addi-
tion to Emil Henriksson, the structures were scaled and drawn by Runo Cairenius,^705
Henriksson’s student friend from Germany and a person using the initials “H.L.”
Henriksson completed a major share of the work.
In the following section, the evolution of the tectonic solution for the sundeck wing
has been approached as a dialogue between the architect and the structural engineer by
organising their respective drawings in a chronological order. This solution, a structure
balanced on one column row, lent itself to further investigation as a result of being
exceptionally demanding to execute, large-scale and architecturally significant. Further-
more, drawings by both the architect and the structural engineer had been preserved,
allowing the sequence of developments to be followed.
701 Aalto [1930]a, p. 8.
702 Ibidem, p. 15.
703 Ibidem, p. 9.
704 Jaakko Hartela’s interview on June 6, 2001 by the author.
705 Runo Cairenius was born in Hanko in 1897 and graduated from the Turku Industrial School building construction
department in 1918 and from Technical School of Sterlitz reinforced concrete department in Germany in 1923.
Between 1923 and 1927, he worked as a master builder on various building sites, as the director of Richard
Helander’s coke cinder plant between 1925 and 1926, and as a constructor at engineer Henriksson’s office in
Turku from 1927 onwards. He invented an extrusion roller for the manufacturing of partition panels and man-made
stones and received Patent No. FI12424 in 1929 for his innovation. Tolonen 1930, pp. 51–52.