A roof segment for the construction of a roof of a carriage body for a rail vehicle, wherein - the roof segment is formed plate-, shell- or half-shell-shaped, - the roof segment consists of an outer wall and an inner wall spaced apart therefrom, - wherein for manufacturing a roof of a carriage body , at least two roof segments are configured such that the projecting portion of the outer wall of one roof segment is connected to the non-projecting portion of the outer wall of the neighboring roof segment and the projecting portion of the inner wall of one roof segment is connected to the non-projecting portion of the inner wall of the neighboring roof segment with a form fit, a force fit and/or an inter-material bond perpendicularly to a longitudinal axis of the carriage body , and - the roof segment consists at least partially of fiber-reinforced plastic composite, - wherein rectangular reinforcing elements are arranged between the inner wall and the outer wall of the roof segment along outer edges of the roof segment , the reinforcing elements being in the form of rectangular hollow profiles, wherein the rectangular hollow profiles form at least one frame and wherein a flat core material is arranged between neighboring rectangular hollow profiles between the inner wall and the outer wall of the roof segment , - wherein the rectangular hollow profiles have a size of 100 mm × 46.5 mm with a wall thickness of 1.5 mm and are braided directly onto a PET rigid foam core in a braiding process or pullbraiding process, - wherein the fibers have a fiber orientation in the ±45° direction and are embedded in a thermosetting matrix made from epoxy resin, - and wherein a flat core material , formed as a PET rigid foam core, is arranged between the inner wall and the outer wall and the frame made of rectangular hollow profiles filled with PET foam and is adhesively bonded to the outer wall . - the roof segment is formed plate-, shell- or half-shell-shaped, - the roof segment consists of an outer wall and an inner wall spaced apart therefrom, - wherein for manufacturing a roof of a carriage body , at least two roof segments are configured such that the projecting portion of the outer wall of one roof segment is connected to the non-projecting portion of the outer wall of the neighboring roof segment and the projecting portion of the inner wall of one roof segment is connected to the non-projecting portion of the inner wall of the neighboring roof segment with a form fit, a force fit and/or an inter-material bond perpendicularly to a longitudinal axis of the carriage body , and - the roof segment consists at least partially of fiber-reinforced plastic composite, - wherein rectangular reinforcing elements are arranged between the inner wall and the outer wall of the roof segment along outer edges of the roof segment , the reinforcing elements being in the form of rectangular hollow profiles, wherein the rectangular hollow profiles form at least one frame and wherein a flat core material is arranged between neighboring rectangular hollow profiles between the inner wall and the outer wall of the roof segment , - wherein the rectangular hollow profiles have a size of 100 mm × 46.5 mm with a wall thickness of 1.5 mm and are braided directly onto a PET rigid foam core in a braiding process or pullbraiding process, - wherein the fibers have a fiber orientation in the ±45° direction and are embedded in a thermosetting matrix made from epoxy resin, - and wherein a flat core material , formed as a PET rigid foam core, is arranged between the inner wall and the outer wall and the frame made of rectangular hollow profiles filled with PET foam and is adhesively bonded to the outer wall . <EOS>