A material for use in lining pipes is disclosed. A warp-knitted tubular fabric (24, 64) in which the stitch used (for example a tricot stitch) is of a type that reconfigures as the tube is expanded radially to contract longitudinally is sufficiently flexible and compressible to enable it to conform to pipe structures. The fabric of this invention is infused with resin, which is cured once the liner is in place within the pipe. Potentially, this fabric may be thinner than known prior art materials, but exhibits comparable strength and conformability, which are necessary characteristics in the repair or rehabilitation of pipes. The use of a thinner fabric material reduces constriction of the pipe bore by repair and also offers the potential for cheaper lining material, as less resin is required. The fabric may be knitted from glass fibre yarn, which is non-toxic and a stronger material than generally used in the prior art.