Thermal Performance of Bamboo Flat Roof Slab and RCC Flat Roof Filler Slab in Warm-Humid Climate

The thermal performance of roof envelopes is one of the major contributors in a building to the indoor temperature and its associated comfort level. Roof envelopes by alternative construction techniques with the involvement of renewable materials like bamboo and stabilized mud are studied and incorporated to achieve the required thermal comfort. In Kerala with its Warm and Humid climate, even though reinforced cement concrete roofs are majorly constructed for residential buildings in recent times, as per research, it does not achieve the required thermal performance with respect to adverse impacts of an increase in temperature, which further pave the way to attain higher heat gain during the summer season. This study is done with respect to the comparative analysis of the thermal performance in real time of flat RCC filler slab roofs and bamboo-mud made flat slabs in two residential buildings in Kerala. Using the required parameters, thermal performance is evaluated through field study, and comparative analysis is carried out. Due to the lower decrement factor of 0.36, a time lag of 6 h and TPI of 76.25%, lower surface temperature, higher outdoor to indoor air temperature variation with 2–3 °C (during peak hot hours), and presence of more air cavity inside bamboo poles than in the filler material of filler slabs, flat bamboo-stabilized mud roof envelope exhibits better thermal performance than flat roof filler slab. This research can add more value to the usage of alternative construction methods over conventional, ones to achieve required thermal performance as well as to minimize overconsumption of non-renewable resources.