Compressed Earth Blocks (CEBs) have been attracting increasing research interest recently, because of their sustainable nature. However, their poor performance against water-mediated weathering is still considered to be a major drawback for contemporary architecture. The aim of this study is to enhance the durability of non-stabilized CEBs produced in Cyprus by optimizing their granular composition. To that end, two locally sourced soils and a fine crushed aggregate were used to produce several CEBs. Spray erosion, drip and capillary absorption tests were carried out to test the performance of these CEBs against liquid ingress. The results suggest that the addition of sand can significantly improve the durability of non-stabilized CEBs against water action.