Sawdust is an industrial waste material which is environmentally friendly, economical as well as lightweight in nature. Timbercrete or sawdust mortar blocks consists of sawdust, cement, sand, and water. The primary goal of this experiment is to analyze fresh stage and mechanical properties of sawdust mortar. Before the actual usage of sawdust in mortar, it was treated with 4% NaOH as sawdust is a biodegradable material. This alkaline treatment ensured the improvement of the mechanical properties of sawdust. Initially, sand was replaced with sawdust by weight. Specimens were cast using a 1:3 mix design, 0.50 water–cement ratio, with 5, 10, 15, and 20% sawdust replacement. But the specimens failed due to a lack of binding and low workability. After a few trials, it could be concluded that the replacement of sand with sawdust by volume with a 1:3 mix ratio works well for all replacement ratios. Further, based on workability, compressive strength, and flexural strength results, it could be concluded that 5% sawdust mix showed satisfactory performance.