The Project GM Klang Wholesale City provides an ideal concept for wholesalers and retailers to source their merchandise conveniently and improve business. There are 5 phases in the project with total development that can house over 1.35 million sq. ft and more than 3000 individual shops. Design Constraints As Phase 1 of the project sets the milestone for its other future developments, the Consultant, namely G&P Professionals Sdn Bhd is faced with the challenges of waterproofing approx. 10,000 square meters of reinforced concrete flat roof car park and also designing the structure within its budget. The Solution Cementaid proposed the 3CC System which make the entire concrete hydrophobic is an effective time-proven alternative to membranes or surface treatments which only have a temporary life-span and require periodic replacement or maintenance. The 3CC System becomes substantive to the concrete matrix and permanently waterproofed the structure throughout its mass, thus providing a long term performance as well as maintenance-free reinforced concrete flat roof car park, which amounts to massive savings to the owner.