Durability

When draped curve 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. The underside of pre-coated roof cladding is provided with a primer and backer coat only; it is not as weatherproof or UV resistant as the top-coat.

Because pre-painted cladding is not intended for use in this micro-climate without regular maintenance, the underside of the soffit should be lined in all severe and very severe environments.
(see Maintenance )