A composite lining element for a tire mould comprises first and second bodies 12, 14 which are able to mould, at least in part, the one same tread pattern in a tread of the tire and each delimiting an exterior moulding surface 12b, 14b and an opposite interior surface 12a, 14a. The composite lining element further comprises at least a means 16 of assembling the first and second bodies. The interior surfaces 12a, 14 of the bodies are kept by the means of assembling at least locally in a separated position that creates an interior space 22.