Abstract: An injection liner for use as a borehole closure in masonry or solid rock provides a passageway for injecting plastics material into a prepared borehole for sealing cracks or fissures in masonry or solid rock. The liner is a unitary shaft having a frusto-conically shaped outside surface arranged to be fitted into the prepared borehole. The shaft is a tubular member and provides an axially extending bore through which the plastics material is forced. A nipple is threaded into the larger diameter end of the shaft so that a hose for the plastics material can be connected to the nozzle for flowing the plastics material into the bore through the injection liner.