We were commissioned by Landscape Architect and garden designer Joanna Herald to provide construction advice and to supply porphyry stone cubes for a permeable installation in South East London. The design consisted of concentric circles of alternating 40-60mm and 60-80mm cubes installed onto a bed of Steintec tuffgrit. Once laid, the entire pavement was compacted with a 150kg vibrating wacker plate, with tuffgrit brushed into the joints to maintain the permeability of the pavement.