Abstract: A plurality of injectors of the present invention are connected to a single source of a high-pressure gas to inject an adhesive material into cracks and delaminated sections of a building concurrently. Each injector has a front piece for attaching to a target area. An assembly comprising an inner container containing an adhesive material and an outer container enclosing the inner container is attached to a single cap to make a liquid-tight and gas-tight connection, respectively, and the cap is attached to the back of the front piece to make a liquid-tight connection by means of matchingly tapered surfaces. The inner container is elastic and has a concave bottom surface so that a high-pressure gas introduced into the space between the inner and outer containers can push out the adhesive material efficiently and smoothly from the inner container through the front piece.