The thickness of a roof slab is a critical factor in ensuring its durability and stability. While the overall thickness of a roof slab is usually kept at 10 cm, the minimum thickness can be 7.5 cm. However, it’s important to note that the minimum area of reinforcement per unit width of a slab should not be less than 0.15%. This reinforcement is necessary to provide strength and support to the slab, especially in areas prone to high wind loads and seismic activity. Therefore, it’s essential to consult with a structural engineer to determine the appropriate thickness and reinforcement required for your specific roofing project. By doing so, you can ensure that your roof is safe, secure and can withstand the test of time.