This test method describes a full-scale reference scenario procedure for assessing the burning behaviour of stairs or stair coverings, when exposed to a defined ignition source. The risks addressed in this scenario are essentially those of a deliberate rather than an accidental fire. The ignition sources specified include a wood crib to represent a local attack with burning crumpled newspaper and a gas burner to represent a more severe attack when the whole width of the bottom step is attacked. The observations of burning behaviour provide a basis for assessing the fire exposure behaviour of stair coverings installed over different stair substrates. This method is applicable to all types of stair coverings that can be installed on stairs or to the stairs themselves. The results obtained from this method reflect the performance of the total stair covering system together with the stair substrate, as tested, and are not intended to be the sole criterion for assessing the potential fire hazard of the product in use. Modifications to the stair covering, underlay, fixing system, stair substrate or other changes to the system can affect test results. Tests are performed with an enclosed or open-sided staircase. In this test method, there is no closure at the top of the stairs to represent a ceiling on a stairs landing. The top of the stairs assembly is open so that the tests are conducted under well-ventilated conditions.