The paper discusses strength-time relation of unfired bricks reinforced with and without natural fibers. Untreated and treated coconut fibers with three different lengths (1 cm, 2.5 cm and 4 cm) were prepared for soil lime bricks reinforcements. The effects of 4% uniform 2.5 cm fiber reinforcement was compared to the effects of 4% non-uniform fiber reinforcement, which constitutes a fiber mix between 1/3 part each of 1 cm, 2.5 cm and 4 cm fiber length. Absorption of brick was also evaluated. Experimental investigations reveal that for all type of bricks, up to 90 days compressive strengths decrease a little but bending strengths rapidly decrease with time. The results show that unfired bricks added with uniform treated fiber resulted in better strength performances compared to those added with uniform untreated, non-uniform untreated and nonuniform treated fibers, and also to those without fibers.