What is the slope usually given on R.C.C flat roof?

🏗️ Understanding R.C.C. Flat Roofs

Reinforced Cement Concrete (R.C.C.) flat roofs are constructed similarly to R.C.C. floors but require additional protective measures against weather elements like rain, snow, and heat. A key design consideration for these roofs is ensuring effective water drainage to prevent pooling (ponding), which can lead to leaks, structural damage, and deterioration of materials over time.

To achieve this, a seemingly "flat" roof is always constructed with a slight, carefully calculated slope, also known as a gradient or fall.

⚙️ Detailed Explanation

The construction of an R.C.C. flat roof involves adding a protective, waterproof layer over the main structural slab.

• Protective Covering: A layer of lime concrete terracing, typically 10 cm thick and often mixed with a waterproofing compound, is applied over the R.C.C. slab. This layer is thoroughly beaten by hand to make it hard, compact, and impervious to water.
• Junctions: At the junction with walls, this terracing is extended 10-15 cm into the wall, and the corner is rounded to prevent water accumulation and leakage at these critical points.
• Slope for Drainage: This final lime terracing layer is not laid perfectly flat. It is given a gentle slope to guide rainwater towards drains or scuppers. The standard recommended slope is typically in the range of 1 in 60 to 1 in 100. This ensures that water drains off rapidly and efficiently without being so steep as to cause issues with roof use or aesthetics. Therefore, 1 in 60 is the most appropriate answer among the given options.

ℹ️ Additional Information