A method for effecting a repair and/or strengthening of a pipe. The method comprises cleaning an affected area of a surface of the pipe to provide a cleaned surface of the pipe surface for an area requiring repair; applying a continuous strip around the pipe from a portion prior to the effected area and allowing the continuous strip to extend to a portion after the affected area. The continuous strip forms a spiral sleeve spaced from the pipe surface to provide an annular chamber between the pipe surface and the spiral sleeve.