A method for building a tyre for a vehicle wheel includes positioning a casing sleeve on a shaping drum and securing the sleeve on the drum. During at least one of positioning and securing the sleeve, the sleeve is kept in an essentially centered position on the drum by radial forces directed against a radially inner surface of the sleeve. A shaping drum for making a tyre for a vehicle wheel includes a rotation shaft and two coaxial half-drums integral with each other with respect to rotation. At least one of the half-drums is axially movable in both directions with respect to the other half-drum. Each half-drum includes a support device, a gripping device, and a centering device. A first equatorial plane defined the centering devices is axially movable with respect to a second equatorial plane defined by the gripping devices. A plant for building a tyre is also disclosed.