Timber ventilated façade

Façade cladding in timber boards — typically larch, cedar or heat-treated wood — fixed to a substructure with a ventilated air cavity in front of the insulation. The timber screen sheds rain and sun; the air behind dries both faces of the boards, keeping rot away. Warm and natural, it is the face of Alpine and contemporary architecture; in time the wood takes on an even grey patina.

A timber ventilated façade is a rain-screen: the boards do not seal the wall, they protect it. They are fixed on battens and a substructure, with a continuous air cavity in front of the insulation fixed to the wall. It is the same logic as a stone or metal ventilated façade, with a living material.

Driving rain is largely shed by the boards; what gets past runs down the cavity and drains away. Above all, the air rising behind the boards dries both their faces: it is this ventilation, not a treatment, that keeps rot away. Timber that stays wet rots; ventilated timber lasts.

Exposed to sun and rain the wood changes colour: left unprotected it takes on an even silver-grey patina, part of its charm. Durable species are chosen (larch, cedar) or heat-treated timber, and the detailing is cared for — drips, distance from the ground, protected end-grain — to lengthen its life. A damaged board can be replaced on its own.

Timber is combustible: on façades, on tall buildings, the fire rules must be met (treatments, non-combustible bands and barriers, compartmenting the cavity). Wood also «moves» with humidity: the boards are fitted with gaps and fixings that allow movement, with stainless-steel screws to avoid corrosion and tannin staining.