Method of rehabilitating manholes by custom lining/relining

A method for lining or relining a sewer manhole, apparatus comprising an improved leak resistant manhole (18), and a cementitious mixture for lining/relining manholes. A homogeneous, monolithic, cementitious liner is spray applied in place within a concrete or brick-and- mortar manhole infrastructure without forms, webbing, or re-bar. A manhole (18) to be serviced is first located and spray cleaned with water. Loose concrete and mortar fragments of the original structure are forcibly removed. A cementitious mixture (24) is spray-applied to the interior surfaces of the manhole (18) to create a continuous, monolithic interior liner (72). This lining is configured substantially identically to the internal shape and geometry of the manhole (18). When the liner sets after installation, a substantially impervious water and chemical resistant barrier prevents manhole ingress/egress by ground water. The preferred cementitious mixture is a lightweight, high silicate, fiber-reinforced blend, which, when mixed with 20% to 40% water by weight and properly spray applied, will produce a monolithic liner having hitherto undiscovered geometric and structural strength characteristics, including improved water impermeability and chemically resistant properties. The disclosed structure and process contribute positively to the promotion of improved sewer system integrity.