Chapter 3 | The Building of Paimio SanatoriumThe open sundecks and balconies were constructed as single-leaf slabs. In this case
the load-bearing structure was a slab resting on a beam or a cantilevered slab. Console
structures were employed in the intermediate floors in C wing and in the corridors of
A wing. Here, the walls beneath and above the window were connected directly to the
floor slab as narrow concrete beams and the internal insulation material was cork.^690 A
free-bearing wall allowed for the use of ribbon windows.
The structural solution of A wing differs from that of the patient rooms and sundecks.
In patient rooms, the building has two load-bearing rows of columns, one of which aligns
with the south-facing external wall and the other with the corridor wall. These columns
support the transverse primary beams, which in turn support the longitudinal secondary
beams. The load-bearing vertical structure in the sundeck wing is one row of columns
balanced with tensioned steel rods cast within the thin rear wall.^691
The sundeck ceilings, parapet and other concrete surfaces were cast with clean joints.
The cast walls were smoothed and coated with thin-coat coloured render. According to
the work specification, similar treatment was applied to the concrete shell on the bottom
section of the chimney, water tank and all balconies and canopies.^692 In these, the cast-
ing surface of the structural elements was left in view. The reinforced concrete structure
contained contraction joints. The architectural drawings showed a detail of the expansion
joint in the ceiling structure.^693 The water tank was constructed around the chimney. It
was made of trowel-finished reinforced concrete and coated on the inside with a seal-
ant.^694 According to the building specification, the air-entrained surface concrete in the
water tank was placed in the formwork before it was filled. The plan was to smooth the
external surface with concrete and cover with thin-coat coloured render. A photograph
taken during the construction reveals that the water tank surface was clad with vertical-
ly-laid roofing tiles, probably redbrick. The outer shell of the chimney, which supported
the water tank, was built from redbrick and left unrendered.^695
The semi-open floor slab of the second floor in the dining hall in the B wing was
supported by a wire construction, suspended from the beams of the third floor. The
construction was enveloped in a cement-filled iron tube.^696 The structural designer drew
a detail of the bottom section of the suspended structure. The architect had sketched
the idea of a semi-open intermediate floor in the competition phase, and it was one
of his most central spatial solutions. It emphasised the importance of the communal
space: the dining and banqueting hall. The medical experts had unanimously rejected
the idea as too expensive before the actual design commission commenced. They had
also recommended that windows be added to the northern wall, to facilitate airing.
690 Ibidem, p. 9.
691 Ibidem, pp. 8–9
692 Ibidem, p. 8.
693 The image shows the attachment of the roofing felt at an expansion joint. Drawing No. 50-382. AAM.
694 Sica was used as a sealant for concrete and render surfaces. Harmia 1937 ed., p. 116.
695 See e.g. photos ar 26-33, ar 26-34 and ar 26-42. AAM.
696 Aalto [1930]a, p. 8.