Abstract: A method for repair of a length of a conduit having a circumferential inner surface, by anchoring to the inner surface in a direction parallel to the length a plurality of sections of tubing of generally rectangular cross-section spaced around the conduit in the circumferential direction, each of the sections of tubing having therein a plurality of openings in a direction parallel to the circumferential direction. A plurality of strips of plastic sheeting is then anchored to the tubing on a surface opposite to a surface of the tubing anchored to the inner surface, with the strips of plastic sheeting extending circumferentially around the conduit along the length of the repair, and defining a space between the plastic sheeting and the inner surface.