Controlled Permeability Formwork (CPF) liners significantly enhance the durability and finish of surface concrete during concrete pour. They are a cost-effective way of potentially doubling the life of concrete structures. The CPF liner is a thermally bonded polypropylene membrane that is placed to the internal face of formwork to provide a high quality and durable surface. It is designed to retain majority of cement and increases the potential service life of all concrete structures. It is generally used in civil, mining, and marine projects.