Apparatus covering at least a portion of a surface of an existing structure with a repair structure comprise: a plurality of longitudinally and transversely extending panels connected to one another in edge-adjacent relationship; and a plurality of standoffs connected to the panels and extending from the panels toward the existing structure. Each panel comprises a panel connector component which extends longitudinally along the panel and from an interior surface of the panel toward the existing structure, and each standoff comprises a standoff connector component complementary to the panel connector component. The connector components are shaped such that a connection formed therebetween comprises deformation of at least one of the panel connector component and the standoff connector component and creates corresponding restorative deformation forces that prevent relative movement between the panel and the standoff under the force of gravity.