A method of manufacturing a cementitious composite including: (1) mixing an extrudable cementitious composition by first forming a fibrous mixture comprising fibers, water and a rheology modifying agent and then adding hydraulic cement; (2) extruding the extrudable cementitious composition into a green extrudate, wherein the green extrudate is characterized by being form-stable and retaining substantially a predefined cross-sectional shape; (3) removing a portion of the water by evaporation to reduce density and increase porosity; and (4) heating the green extrudate at a temperature from greater than 65° C. to less than 99° C. is disclosed. Such a process yields a cementitious composite that is suitable for use as a wood substitute. Particularly, by using higher curing temperatures for preparing the cementitious budding products, the building products have a lower bulk density and a higher flexural strength as compared to conventional products. The wood-like building products can be sawed, nailed and screwed like ordinary wood.