US Patent 7279196 Liner for waste water system rehabilitation

A technique and device for rehabilitating or repairing waste water system components or the like, comprising a spray-applied, multi-layer liner which seals the components and imparts structural integrity. The liner comprises a primer layer, a first moisture barrier layer, a foam layer and a second moisture barrier layer. The first and second moisture barrier layers are preferably made of the same material and form a skin on both sides of the internal foam layer. The combination of the foam layer and the two moisture barrier layers imparts structural strength and rigidity to the cured liner.