Is Sarking Required Under Colorbond Roof

Sarking and the building code of australia.

Is sarking required under colorbond roof.

Sagging of sarking to avoid the sarking contacting the underside of the roof sheet but not more than 40mm is recommended to avoid temperature transfer from the roof sheet. Roof sarking improves performance and comfort by providing the following benefits. Roof sarking is mandatory in all bal 12 5 to 40 rated areas to meet the bush fire ember attack requirements in accordance with australian standard 3959 where it provides a secondary form of ember protection for the roof space1. Csr recommends that all tiled roofs with a pitch of less than 20 are sarked and the bca mandates this requirement for rafter lengths greater than 4 5 metres.

In bushfire prone areas flying embers cannot enter this space through the roof due to sarking protection. Ventilated roof spaces in high humid climates like queensland that are under metal roofs can result in excessive condensation within the roof space at night. The other type is called underlayments aka sarking. The flexible membrane is usually installed under the battens to provide thermal insulation and to prevent water and dust penetration in the roof space.

A layer of sarking reflective foil laminate or rfl is then put in place. Vapour permeable sarking controls the risk of condensation by allowing water vapour to be. Sagging of the sarking to facilitate drainage to the gutter is required but not more than 40mm. In many installations both are installed.

It is mandatory under the building code of australia bca that all tiled residential roofs regardless of roof pitch with a rafter length greater than 6 metres must be sarked. Sarking is not mandatory however it helps to protect your roof frames from acquiring moulds stains and other decaying issues. While this isn t strictly compulsory in all cases sarking s generally considered to be very important for metal roofs to help prevent condensation.