Process for building an additional component within a vulcanised tyre comprising: a) arranging a vulcanised tyre having an external surface and an internal surface arranged around a rotation axis of the vulcanised tyre itself and grasping said vulcanised tyre by means of a grip device, b) executing a preliminary scan of at least one deposition portion of the internal surface of said vulcanised tyre, c) generating a mathematical model of said at least one deposition portion on the basis of said preliminary scan, d) executing a deposition process for depositing at least one layer of said additional component directly on said at least one deposition portion, wherein said deposition process comprises: d1) positioning, at a starting position and at a relative distance from said at least one deposition portion, a dispensing nozzle configured for dispensing a continuous elongated element, d2) activating a continuous dispensing of the continuous elongated element through said dispensing nozzle, d3) generating a relative deposition motion between said dispensing nozzle and said vulcanised tyre, starting from said starting position and simultaneously with said continuous dispensing, following a trajectory according to said mathematical model adapted to make a spiral deposition of the continuous elongated element on said at least one deposition portion up to the building of said layer, e) controlling said deposition process by means of the adjusting of at least one deposition parameter as a function of the mathematical model of said at least one deposition portion. a) arranging a vulcanised tyre having an external surface and an internal surface arranged around a rotation axis of the vulcanised tyre itself and grasping said vulcanised tyre by means of a grip device, b) executing a preliminary scan of at least one deposition portion of the internal surface of said vulcanised tyre, c) generating a mathematical model of said at least one deposition portion on the basis of said preliminary scan, d) executing a deposition process for depositing at least one layer of said additional component directly on said at least one deposition portion, wherein said deposition process comprises: d1) positioning, at a starting position and at a relative distance from said at least one deposition portion, a dispensing nozzle configured for dispensing a continuous elongated element, d2) activating a continuous dispensing of the continuous elongated element through said dispensing nozzle, d3) generating a relative deposition motion between said dispensing nozzle and said vulcanised tyre, starting from said starting position and simultaneously with said continuous dispensing, following a trajectory according to said mathematical model adapted to make a spiral deposition of the continuous elongated element on said at least one deposition portion up to the building of said layer, d1) positioning, at a starting position and at a relative distance from said at least one deposition portion, a dispensing nozzle configured for dispensing a continuous elongated element, d2) activating a continuous dispensing of the continuous elongated element through said dispensing nozzle, d3) generating a relative deposition motion between said dispensing nozzle and said vulcanised tyre, starting from said starting position and simultaneously with said continuous dispensing, following a trajectory according to said mathematical model adapted to make a spiral deposition of the continuous elongated element on said at least one deposition portion up to the building of said layer, e) controlling said deposition process by means of the adjusting of at least one deposition parameter as a function of the mathematical model of said at least one deposition portion.