GRP reduces the risk on CUI. (Corrosion Under Insulation) Traditional aluminium jacketing is easily damaged or dented and joints are not always watertight. As a result these situations lead to unwanted water ingress. Due to it's mechanical strength, GRP allows "stepping" on insulation. Also GRP provides watertight seams. Due to the UV curing property, the installation doesn't require specials tools or prefab shops. And in combination with VaporStop foil GRP provides an excellent vapourbarrier.