The invention relates to a device for manufacturing coated materials, the device comprising: a furnace comprising an enclosure (2) that is designed to be caused to rotate, that has an inside wall (2A) and that is provided with a main inlet (3) designed to receive non-coated new granular materials (25) or recycled granular materials (25) or a mixture of both of these types of granular materials, and an outlet for the bituminous coated materials that are manufactured inside the enclosure (2); heater means defining a combustion zone (4) inside the enclosure (2) and generating a drying flow suitable for drying the granular materials (25); and protective means for protecting the inside wall (2A), which means are situated in the combustion zone (4); said device being characterized in that the protective means are formed by a plurality of plates (13) that extend at some distance away from or else against the inside well (2A), and that are mutually overlapping in part so as to protect the inside wall (2A) thermally. Methods and devices for bituminous coated materials.