This study was conducted to evaluate the properties of insulation boards made from bamboo paper sludge and fly ash floating beads. An orthogonal test design was applied to study the effects of certain factors on the properties of the insulation boards. The results indicated that the sequence of significant effect of factors on the properties of the composite boards was particle size of bamboo paper sludge, thickness of boards, and weight ratio of sludge to fly ash floating beads. The verified optimal conditions were confirmed to be 20 to 40 mesh, 80:20, and 14 mm, representing the particle size of bamboo paper sludge, weight ratio of sludge:fly ash floating beads, and thickness of boards, respectively. The thermal conductivity of the bamboo paper sludge and fly ash floating beads insulation boards was measured and suggested that both insulation boards had thermal conductivity values ranging from 0.12 to 0.165 W/mK, which is close to the conventional insulation material lightweight concrete.