Natural composite materials have been used in many fields to save the environment. Especially, teak sawdust and wood ash, due to their environmental sustainability, mechanical properties, and recyclability, have been utilized in applications such as making boat hulls in marine engineering. The main objectives of this paper are to use teak sawdust, wood ash, and sisal fiber to make the composite material. This experiment focuses on changes in mechanical properties of wood ash and sisal fiber with an epoxy resin matrix with different volume ratios of teak sawdust reinforcement, fabricated using the hand layup method. Composite materials with various weight percentages, such as 10% teak sawdust (R1) and 20% teak sawdust (R2) reinforcements, were developed with 150 and 300-micron particle sizes. The mechanical properties analyzed include impact resistance, hardness, and water absorption. © 2021 Elsevier B.V., All rights reserved.