23/06/2025
Hand Rules” Every Civil Engineer Must Know On-Site 🏗️
Civil engineering is not just about design & drawings—it’s also about making quick, smart decisions on-site. That’s where these practical “hand rules” come in. These are field thumb rules that help engineers save time, ensure quality, and maintain safety.
📌 Here are the most useful thumb rules for civil engineers:
🔹 Concrete Work
✅ Mix Ratio (M20): 1:1.5:3 (Cement : Sand : Aggregates)
✅ Water-Cement Ratio: ~0.5 (for general work)
✅ 1 Bag of Cement = 35 litres or 0.035 m³
🔹 Brickwork
✅ 1 m³ Brickwork = ~500 bricks
✅ Mortar Quantity (1:6): ~0.3 m³ per 1 m³ brickwork
✅ Brick Wall Thickness:
– Half brick = 115 mm
– Full brick = 230 mm
🔹 Steel Reinforcement
✅ Steel in Slab: 80–100 kg/m³
✅ Steel in Beam: 100–120 kg/m³
✅ Steel in Column: 120–150 kg/m³
✅ Weight of Bar (kg/m): (D²)/162 (D = diameter in mm)
✅ Clear cover:
– Slab: 15–20 mm
– Beam: 25 mm
– Column: 40 mm
– Footing: 50 mm
🔹 Shuttering & Centering
✅ Shuttering oil coverage: 1 L ≈ 10–12 m²
✅ Stripping time:
– Slab: 7 days
– Beam: 14 days
– Column: 7 days
🔹 Plastering & Flooring
✅ 12 mm plaster covers: ~80–90 m² per m³
✅ Cement consumption for plaster (12 mm, 1:4): ~0.2–0.25 bags/m²
✅ Tile adhesive per m² (6–8 mm): ~4–5 kg/m²
🔹 Bar Bending & Stirrups
✅ Length of a stirrup: (2A + 2B + 24d)
✅ Stirrup spacing in beam:
– Near support: 100 mm
– Mid span: 150 mm
🔹 Load Bearing Estimates
✅ 1 m³ RCC weighs ~2500 kg
✅ 1 m³ brickwork weighs ~1800 kg
✅ Live Load (residential): 2 kN/m²
💡 NOTE: These thumb rules are only for quick checks. Final work should always follow detailed drawings and IS codes.
👷♂️ Whether you are a fresher, intern, or junior engineer — save this post, use these rules, and become smarter on site!
