Abstract This study evaluates the feasibility of utilizing spent mushroom waste (SMW) as a sustainable partial replacement for clay in the manufacturing of lightweight, thermally insulating roof tiles. Clay was partially replaced with 0–25 wt% SMW and fired at 1,000, 1,050, 1,100, and 1,150 °C. Increasing SMW content decreased bulk density from 2,204.67 to 1,390.88 kg m −3 (at SMW-25, 1,150 °C) and reduced thermal conductivity from 0.95 to 0.237 W m −1 K −1 , owing to porosity generated by organic matter burnout. The transverse breaking strength declined with SMW but recovered at higher firing temperatures; at 1,150 °C, the TBS values were 3,067, 2,785, 2,276, 1867, 1,150, and 987 N for 0–25 % SMW, respectively. Tiles containing 5–20 % SMW fired at 1,100–1,150 °C met the ASTM C1167 requirements for Grade 2–3 roofing tiles, while achieving substantial reductions in weight and thermal conductivity. Tiles passed the ASTM C1167 water permeability test and showed no efflorescence, as per ASTM C67. Based on density reduction, tiles containing 20 % SMW fired at 1,150 °C showed a 36 % decrease in density relative to conventional tiles. These results demonstrate that SMW enables lightweight, thermally insulating roof tiles that satisfy relevant standards while valorizing an abundant bio-residue.
Matar et al. (Thu,) studied this question.