Detailing of well ends and balustrades

The solid profile of in-situ concrete stairs draws attention to the riser and well-end relationship. The appearance of sloping soffits and their bisection is of critical importance (Figures 8.5a and 8.5b) unless trimming beams or thicker slabs across the landing hide the junctions (Figure 8.5c). This may however appear clumsy. The alignments are compounded by the handrail-to-riser geometry, where 'slipping' the riser plane by one full step will improve matters (Figure 8.5 b). It will be noted that the handrailing bisects in the same plane as the soffit and that no jump is incurred for the wreathing. In other words, the alignment gives 'slope to horizontal to slope' in the handrailing at well ends. By comparison, Figure 8.5a gives a vertical jump that is visually awkward.

Lengthening the well is another possibility with the use of a semicircle to set out handrail and well end. A well width equal to the tread will give a lift to the handrail in sympathy with the pitch to the flight (Figure 8.5d). A compromise which saves a few centimetres of space is the arrangement in Figure 8.5e where the riser plane is slipped by half a step. There are limitations, however, on aesthetic issues, particularly where a matching balustrade pattern is needed either side of the stairwell. In these circumstances non-conventional solutions such as solid fender walls or face-mounted railings will have to be explored (Figure 8.5j).

Generous layouts as in Figures 8.5 b and 8.5d give better value in visual terms for both balustrade and well shape despite adding 250 mm (average tread) x stairhall width to the unlettable area of space.

Galvanized steel angle frame to landing (infill of pre-cast slates)

Galvanized steel angle frame to landing (infill of pre-cast slates)

Figure 8.4a Pre-cast spiral stairs: Typical components using pre-cast treads and steel tubular column

Figure 8.4d Context of artificial stone stairs set against stone work, Carcassone, 18 70s

Figure 8.4b Finished tread with terrazzo surface of different colours including non-slip insets

Figure 8.4c Artificial stone finish to spiral stair (courtesy of Cornish Spiral Stairs Ltd)

Metal balustrades to concrete stairs follow the principles laid down in Chapter 7, the differences arising if reinforced concrete fender spine walls are involved. The advantages of the latter rest with less metalwork to install and maintain. Figure 8.5g demonstrates Aalto's detailing at the Paimio Sanitorium as a superb example. The photograph was taken in 1968 when the original finishes were still intact. Another version of the concept could be made by using pre-cast terrazzo to the strings to receive the railings, with the flights also pre-cast with terrazzo tile finishes (Figure 8.5h).

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Plan detail for minimum scheme

Better solution with staggered relation to riser and neat soffits line (to

Figure 8.5a and b Detailing of well ends: Sloping soffits and their bisection, good and bad solutions

Figure 8.5c Beam or thick landing slab to mask intersection lines

Figure 8.5d Lengthening the well

Compromise scheme

Figure 8.5e Half-step relation across well

Figure 8.5/ Face mounted railings

Figure 8.5g Fender walls with least balustrading, Paimio Sanitorium, Finland, 1933, Architect: Alvar Aalto

Figure 8.5h Fender in pre-cast terrazzo
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