We introduce rational Dyck tilings, or (a, b)-Dyck tilings, and study them by the decomposition into (1, 1)-Dyck tilings. This decomposition allows us to make use of combinatorial models for (1, 1)-Dyck tilings such as the Hermite history and the Dyck tiling strip bijection. Together with b-Stirling permutations associated to the rational Dyck tilings, we obtain a correspondence between an (a, b)-Dyck tiling and a tuple of ab (1, 1)-Dyck tilings.