Identification of the main factors affecting waterproofing problems of reinforced concrete (RC) flat roof : a case study of Perkeso buildings

Abstract

In Malaysia, it is crucial to have a good waterproofing system as it receives frequent rainfall all the year round with an average rainfall of 250 centimetres. With a proliferation in popularity of flat roof system especially for high-rise buildings, waterproofing problems are considered critical to avoid damages to the building and its content. Ironically the failure of remedial works were also common. Current approaches address the problems were on ad hoc basis and merely corrective rather than preventive. As a result, more damages and costly repair become apparent in the maintenance budget. However, recent roof leakage incidents at numerous prestigious buildings such as Parliament House, high court and other government buildings has sparked awareness among the building owners and engineers to fully understand the importance of a good waterproofing system. The aim of this study is to identify the main factors affecting the performance of waterproofing system for flat roofs at selected buildings owned by Pertubuhan Keselamatan Sosial (PERKESO). Two objectives are set to achieve the aim. They are; (1) to identify the deficiency of waterproofing performance; (2) to identify ways to have the best performance of waterproofing system. This study involves three PERKESO buildings as case studies. Acquisition of primary data was carried out through investigation via interview, the records of maintenance and site observation. Secondary data involves the manoeuvre of factors found in the literature reviews such as application methods, weather elements, usage of the flat roof, substrate condition and budgetary constraint. Comparative analysis was carried out to gauge the significant cause of the waterproofing problems. Findings of this study indicate that the ‘workmanship’ as the main factor that contribute significantly to the problems. The outcome could be useful as guidance for better building maintenance management. With those factors determined, recommendations are presented to improve the performance of waterproofing system and thus could reduce the maintenance cost.