ISO 13785-1:2002 specifies a screening method for determining the reaction to fire of materials and constructions of façades or claddings when exposed to heat from a simulated external fire with flames impinging directly upon a façade. It is intended for use by producers to reduce the burden of testing in ISO 13785-2:2002 by eliminating those systems that fail the tests described in ISO 13785-1:2002. The test method consists of observing the behaviour of the façade panel construction to fire and the resulting flame spread on or within the façade construction. This test method is applicable only to façades and claddings that are not free standing and that are used by adding to an existing external wall. This test method also is applicable only to vertical elements and is not applicable to determining the structural strength of the façade or cladding.