To provide an outer wall reinforcing method and an outer wall reinforcing structure in which the state of lathing can be seen even through fibers of a reinforcing fabric, trowel workability is improved and the appearance of lathing can be maintained.

According to an outer wall reinforcing method, a fiber reinforcing fabric and a resin are pasted to lathing through impregnation and application. The fiber reinforcing fabric is a woven fabric or unwoven fabric comprised of monofilament fibers, and the resin is an urea resin of a non-aromatic ring. The appearance of lathing is not shielded even under the fibers. Regarding an outer wall, the time to double the initial viscosity thereof at 23°C after mixture is 5 minutes or more, the outer wall can be applied with a trowel, and the lathing is covered with tiles. Furthermore, as the monofilament fiber woven fabric, polypropylene resin fibers may be efficient. Moreover, an outer wall reinforcing structure obtained by the outer wall reinforcing method is also provided.