The regulations dealing with external wall cladding are set out in the ABCB Housing Provisions which can be accessed via the relevant website. Section 7.5 deals with timber cladding and focuses largely on adequate fixings and sarking, rather than species. Manna gum and messmate are rated Class 3 durability outdoors above ground according to Australian Standard 5604, Timber - Natural durability ratings, ie. they are not highly durable species. However, neither are some other species traditionally used for cladding, such as Baltic pine.

We have CRF and Smoke Development values for a number of timber species, but unfortunately not for Baltic pine. Nor do we know of a source of this data. Perhaps the importer could provide details, or arrange for the required tests.