Controlling heat gains in buildings is a key focus area which should be addressed to achieve sustainable thermal comfort and energy savings in buildings. About 75% of the thermal energy incident on a building envelope travels via the roof. Accommodating low conductive ceiling sheets can control the heat transfer in the building, resulting in improved thermal comfort with a significant energy saving. However, the utilization of waste materials in the fabrication of ceiling sheets will yield sustainable goals in construction. This paper presents an innovative approach of developing a roofing sheet using waste materials, including Polyethylene terephthalate plastic ((PET) water bottles), Extruded Polystyrene Foam (EFF), waste polythene (Low-density polyethylene (LDPE)) and coconut coir fibers. Three distinct binding materials were combined in six different mix ratios to create a total of eighteen types of sheets. The Scanning Electron Microscopy (SEM) images reveal that the samples containing coir fiber and LDPE exhibited a homogeneous layer and also the measured properties indicated low void ratio with enhanced dry density and reduced water absorption in developed sheets. This study showed the possibilities of producing ceiling boards with coir fiber and LDPE with excellent mechanical, thermal and durability performance.