This research presents a characterization of rice husk ash to an appropriate particle size for their performance as fine aggregate in adhesive mortars for laying of ceramic tiles, due to the high percentage of silica in its chemical composition. The physical and chemical properties of aggregates are analyzed and the mechanical behavior of fluency and tensile strength of the mortars obtained with partial replacement of sand in percentages from 5% to 25%, proposing the use of waste rice husk ash and presenting an alternative to decreasing sand exploitation, which causes serious environmental impacts. The results show that a percentage of replacement of the sand by rice husk ash in a 20% produces tensile forces comparable with those obtained for commercial adhesives.