Durability

When curved roofs are unlined and used as canopies or exposed eaves, the underside of the sheeting becomes an unwashed area. Therefore, it needs to be washed and regularly maintained to comply with the durability requirements of the NZBC and the supplier's warranty. Because pre-painted cladding is not intended for use in this type of micro-climate without regular maintenance, the underside of the osiffit should be lined in all severe and very severe environments. (see Maintenance. )