working details: A rainscreen of fibre cement boards
The apartment building consists of four split-level storeys, rooftop rooms and a roof terrace. The structure - of cast in situ concrete - has 200mm thick walls, which are clad with aluminiumbonded insulation panels and an outer rainscreen of Eternit Weatherboard fibre cement boards. The product was chosen for its stability and its surface texture, which resembles strongly grained timber-boarded shuttering. Although intended for use in overlapping 'ship-lap' construction, the boards - 8mm thick and 190mm deep - are installed horizontally with gaps between. The gaps vary in depth, increasing as they rise up the building, from 8mm at the base to 178mm at the roof terrace.
The cast in situ concrete walls were waterproofed with a liquid bituminous membrane. The rainscreen fixing system consists of L-shaped brackets bolted to the concrete, which support a series of Fischer vertical Tshaped extruded aluminium cladding rails. The boards are clipped to the rails, which are set at 610mm centres, the maximum recommended distance a board can span. The boards were set out on the facade to standardise lengths and allow for window openings; only six different lengths - indicated by different shades - were needed to cover the facade.
Behind the rainscreen the walls are lined with 600 x 1,200 x 60mm panels of rigid insulation bonded to stucco-embossed aluminium sheet.As the gaps in the fibre cement boards widen, the silver aluminium surface is perceived behind. The aim was to 'vary the perceived mass of the building'and reflect light.
A series of tilt-and-turn double-glazed timber windows rest in openings formed in the concrete wall. Folded aluminium flashings project at head, jambs and sill to close the insulated panel and rainscreen cavity.