10/11/2025
🌟 Why Lapping?
When a single bar is not long enough → we overlap 2 bars
To make them behave like one continuous bar
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📍 Where to lap in a column?
Bottom 1/4rd zone ❌ (Tension zone)
OR Top 1/4rd zone ❌ (Tension zone)
Lap in middle 1/2rd zone✅ (Lapping zone)
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📏 Lap Length ( mentioned in detailing of r/f )
≈ 50 × bar diameter (in tension)
Examples:
12mm → 600mm
16mm → 800mm
20mm → 1000mm
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🧲 How many bars can be lapped at one level?
Maximum 50% bars at the same level
Remaining bars should be lapped at a different level → this is called staggered lapping
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🌀 detailing in lap zone
Stirrups spacing should be closer / tighter (approx 100 mm)
Bars must be properly tied with binding wire
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❌ Avoid these mistakes
Never lap at top and bottom 1/4 of floor height
Never lap all bars at same level
Do not lap near beam–column joint region
Thankyou ❤️
