02 | Swiss Sound Box | Peter Zumthor

The Swiss Sound Box was composed of over 40,000 timbers arranged in stacks. Each timber used was cut immediately before being shipped to the construction site in a green state. The primary wall component had a 100 x 200 millimeter [3.9 x 7.9 inch] rectangular section. These timbers were stacked in alternating layers with smaller blocks of wood running set perpendicular to the wall. The small blocks were 45 x 45 x 544 millimeters [1.8 x 1.8 x 21.4 inches] and allowed air to circulate around the larger timbers.

Every timber used in the Swiss Sound Box was unscathed by the construction process; the timbers were not screwed, nailed, or adhered. Instead, the stacks were held together through friction resistance. The timbers were placed precisely in stacks using templates and scaffolding. After placement, the stacks were compressed using a system of stainless steel tension rods and steel springs. The tension systems were placed every 3 meters [9.8 feet] along the stacks and were anchored at the bottom to steel plates and at the top to a cap element that spanned across the wall. The springs were integral to the system as they allowed the compression system to maintain constant pressure despite the fact that the wood was constantly changing shape.

IAT - Swiss Sound Box Stack Assembly - 14.09.18

Image | © Chad Schwartz