PURPOSE: To form a varied ridge section by stacking ridge flat tiles, to which wing sections are shaped through step sections formed in arbitrary height, by arbitrary combination from both side edges of a tabular base body and fitting the step sections to fitting sections.

CONSTITUTION: Wing sections 5, 5a projected to the outside and lower sections through drooping step sections 4, 4a in specified height are shaped integrally from both side edges of the tabular base body 2 of a ridge flat tile 1. Fitting sections 7, 7a having predetermined stacking clearances are notched among the step sections 4, 4a on the insides of positions corresponding to the step sections 4, 4a of the lower sections of the wing sections 5, 5a. The ridge flat tiles 1 to which the height of the step sections 4, 4a is shaped arbitrarily as required are superposed and placed to a ridge section by optional combination, and each fitting section 7, 7a and the step sections 4, 4a of the ridge flat tiles 1 located at the lower sections of the fitting sections are fitted.