Abstract-This study examines potential waste diatomite and sodium silicate sand reuse to prepare water absorption and retain porous ceramics. The operating conditions are constant pressure (5 MPa), sintering temperature (1000-1270 o C), sintering time (2 h), waste diatomite containing sodium silicate sand at different proportions (0-20 %), respectively. The porous ceramic samples containing sodium silicate sand show low thermal conductivity properties (0.278-0.562 W/mK), probably owing to the more pores than those in the concrete (1.458 W/mK). Water release (t 1/2 value) by the porous ceramic samples is decelerated by porous ceramic samples containing sodium silicate sand, due to the synergy effect of high water absorption by the sodium silicate sand and better than in the foamed glass material (4 h). Porous ceramic samples containing sodium silicate sand is highly promising for use in water absorption and retention applications.Index Terms-Porous ceramics, thermal conductivity, compressive strength, sodium silicate sand.