Roofing Calculator
Calculate sloped roof area and the number of roofing sheets needed.
📐 Roof Area = Plan Area ÷ cos(Pitch) · Sheets = (Roof Area × (1 + Wastage%)) ÷ Sheet Coverage
The roofing calculator estimates materials and cost for roofing projects — flat RCC roofs (most common in India), sloped roofs (corrugated sheets, Mangalore tiles, polycarbonate), and roof waterproofing. It calculates concrete volume, reinforcement weight, shuttering area, and waterproofing material quantities to give a complete roofing project estimate.
📋 How to Use This Calculator
Select roof type (flat RCC slab, corrugated GI sheet, colour-coated metal sheet, clay/Mangalore tiles, or polycarbonate). For flat RCC: enter slab dimensions and thickness. For sloped: enter plan area and pitch. The calculator shows concrete volume and mix materials, reinforcement quantity, and waterproofing material requirements. Labour and total cost estimates are included.
💡 Key Facts & Information
Flat RCC roof: standard slab thickness 4–6 inches (100–150mm). M20 concrete is standard for roofs. Reinforcement: typically 8–10 kg per m² of roof area for residential construction. Roof waterproofing options: bituminous membrane (torch-applied or self-adhesive), crystalline waterproofing (Kryton, Sika, Dr.Fixit), or APP/SBS modified bitumen. Corrugated GI/colour-coated sheets: coverage 0.6–0.7 m² per metre (10–15% overlap). Mangalore tiles: 15–16 tiles per m². Flat RCC roofs in India need waterproofing treatment in addition to concrete (brick bat coba or membrane) as flat roofs without waterproofing leak within 2–5 years due to thermal cracking.