A mixture composition of a cellulose ether made from raw cotton linters
and at least one additive is used in a cement based dry mortar
composition wherein the amount of the cellulose ether in the tile cement
based dry mortar composition is significantly reduced. When this cement
based mortar dry composition is mixed with water and applied to a
substrate, the water retention, thickening behavior, and/or sag
resistance of the wet mortar are comparable or improved as compared to
when using conventional similar cellulose ethers.