The sources of defects and the impact of significant factors including ˇ®design', ˇ®material', ˇ®construction' and ˇ®maintenance' on the occurrence of defects in wet areas of 56 non-residential high-rise buildings were studied. Fourteen important risk factors affecting the level of maintainability of wet areas were identified. The study has shown that among the frequency of the occurrence of defects, water leakages ranked the highest with 53%, followed by corrosion of pipes 50% and spalling of concrete 47%. The occurrence of all defects has been broadly attributed to their sources of deficient construction 43%, material 37%, design 11% and maintenance practices 9%. The implications of six key factors of maintainability of wet areas namely water-tightness, spatial, integrity, ventilation, material and plumbing on the occurrence of 14 most common defects found in wet areas were evaluated.