A Complete Guide to Roof Casting (Slab) Costs and Materials

The roof (RCC Slab) is the most critical structural component of your house. It requires meticulous planning, the right mix of materials, and proper curing to prevent leaks and cracks.

The Ideal Concrete Mix (M20 Grade)

For a standard residential roof slab, an M20 grade concrete mix is recommended. The standard ratio is 1:1.5:3 (1 part Cement, 1.5 parts Sand, 3 parts Aggregate). Always use a mechanical mixer and ensure the water-cement ratio is strictly maintained.

TMT Steel Reinforcement

The density of steel required for a roof slab generally ranges from 80kg to 100kg per cubic meter, depending on the span between your columns. Tip: Do not use rusted steel. Ensure the shuttering is perfectly leveled before the steel mesh is tied.

Curing is Mandatory

The strength of your roof depends entirely on how well it is cured. Once the concrete sets, build small mortar ponds on the roof and keep it flooded with water for a minimum of 14 to 21 days.

Waterproofing

Add liquid waterproofing compounds directly into the concrete mix during casting to ensure a dense, leak-proof slab.

👉 Calculate the exact bags of cement, tons of steel, and cubic feet of sand required for your Roof Casting here.