A composite thermoplastic liner for use as a moisture barrier comprises a hollow tubular body made from a woven composite thermoplastic material configured to substantially block the ingress of moisture; and an opening at one end of the hollow tubular body for intake into the hollow of the hollow tubular body. In one aspect a welded closed opposite end forms a base configured to substantially block the ingress of moisture external to the hollow tubular body. In another aspect the woven composite thermoplastic material comprises an electrically conductive additive. In another aspect there is a gusset in at least one side of the hollow tubular body. The hollow tubular body is able to be flattened with the respective gussets formed from folds of the hollow tubular body, such that in the flattened state the tube is more readily stored in a narrow form, but is expandable when the gusset is unfolded.