Suspended false ceilings are commonly installed as a new interior design feature in modern buildings of the Far East. Different shapes, profiles, materials and installation methods were adopted. There are fire safety concerns on extending the activation time and disturbing the water spray pattern of sprinkler systems. Ceilings with timber products might also be ignited. It is necessary to study the differences in thermal environment of a fire in rooms with and without suspended ceiling features.Full-scale burning tests on wood perforated ceilings were carried out to study the indoor temperature distributions in a room fire. Two small fire sources of 250 kW and 500 kW were set up in a room of size 3.6 m by 2.4 m and height 4.5 m. Air temperatures at both the solid ceiling level and the perforated false ceiling level were measured. Effect of perforated ceiling on actuation of liquid-in-bulb sprinkler heads was also studied. The time to actuate the sprinkler heads mounted at the solid ceiling level and the perforated ceiling level were measured.Tests results indicated that the perforated ceiling would affect the room fire behavior. Both the ceiling layer temperature and the maximum room temperature are affected. Effect on the room air temperature depends on the configuration of the perforated ceiling such as the degree of perforation, materials and mounting height. The orders of magnitude of the fire sources used in these tests would represent the room temperature distribution in the early stage of an accidental fire. Information in the early stage of a fire is useful to study its effect on thermal activation of fire service installations. For a larger fire size, the combustible cell ceiling was ignited and burned. Further tests on the effect of heat contribution from a combustible cell ceiling are recommended.