In the article “The Concrete advantage” from the green rooftops’ website, the National Ready Mixed Concrete Association (NRMCA) explains why a concrete green rooftop is simple, inexpensive and durable compared to a membrane system. The concrete roofs are more feasible which ensures better investment for the society and owners. It is waterproof by nature which eliminates the need for waterproofing sub-contractors. This allows for a quicker construction and lower building cost. On top of that, it is highly probable that a root barrier is not required as well. The concrete green roofs do not deteriorate over time and it is easy to maintain. Unlike the membrane system, cracks are easily detected through leakages and fixing it only requires an injection.