Walluminium (pilot certification)

Walluminium is an industrialized construction system that integrates three functions —load-bearing structure, ventilated façade/roof, and solar collector— into a single extruded aluminium component. It enables the complete resolution of the building’s load-bearing envelope, fully finished on the exterior. The Walluminium construction system is composed of cassette-type cladding panels with a C-shaped section, made of extruded aluminium. This patented system belongs to the group of modular construction systems and the subgroup of lightweight metallic structural systems.

The wind barrier is achieved using a water vapour diffusion-open membrane on the cold exterior side of the XPS insulation, such as the breathable membrane DO 135 by Riwega. The system includes expansion joints in plan every 300 mm, each 1 mm wide, sealed with 10x3 mm foamed EPDM to prevent noise caused by thermal movements. These expansion joints allow movement in plan and at the connection with the foundation. In section, the structure is homogeneous and made of the same material, with components measuring up to approximately 3–4 meters for single-story houses and up to 6 meters for two-story houses. The structure is ventilated and expands uniformly in section, without constraint or stress from differential expansion with other materials. The connection between the exterior aluminium structure and the inner insulation layers is resolved through flexible mechanical anchors made of 6 mm stainless steel rods, spaced every 900 mm. These elastic mechanical anchors, along with the airtight membrane slack (greater than 5 mm every 3.00 m), allow independent thermal expansion movements, decoupled from the structure. The construction system is certified under the assumption of a light-colored surface finish for the aluminum panels (white, light gray, etc.). For other colours, however, additional calculations must be carried out based on the building’s geographic location to verify that excessive surface temperatures will not occur.