Full-scale 5re experiments were carried out in an ISO room to study the behaviour of commonly used cellulosic lining materials in real 5re conditions. In addition to the temperature measurements recommended by the ISO 9705, temperature recordings were made at each node of grid lines on the wall lining surfaces. Four lining materials were chosen to represent di4erent types of products and the surface spread of classi5cations determined using the BS 476 Part 7 6ame spread test environment. The linings included 5re retarded, melamine faced and non-5re retarded boards which facilitated a comparative study of the behaviour of these materials with respect to ignition, 6ame spread, heat release rate and time to 6ashover. Corner 5re scenarios were used in all the experiments. A T shape 6ame spread pattern on the surface of the two adjacent walls was observed prior to 6ashover. Prior to the onset of 6ashover conditions, downward opposed 6ow surface 6ame spread to the wall/ceiling intersection. For the non-retarded wood based materials, such as plywood and medium density 5bre board, 6ashover conditions occurred approximately 4 min after the start of the experiment. However, the 5re retarded chipboard ignition was delayed by some 11 min 45 s after which 6ame spread was very rapid with 6ashover occurring within a further 1 min 45 s. An explanation for this particular behaviour is the considerable pre-heating which occurred during the pre-ignition period. For the 5re retarded linings, much higher surface temperatures were recorded compared with those for non-5re retarded linings. It was found that the areas of the 5re retarded linings facing the source 6ame su4ered extensive pyrolysis and charring which penetrated to the rear surface of the lining.