Phase 1: Visual Inspection for Damage

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The first step is a forensic check of the building's health. Distress signals often indicate the building is already struggling under its current load.

• Structural Cracks: Inspection for diagonal cracks in beams or columns (indicating shear failure) and vertical cracks in walls (indicating settlement).
• Deflection: Checking if the existing floor slabs are sagging.
• Corrosion: Identifying signs of spalling concrete or rusted steel exposure in the ceiling or sunshades.

If the building shows significant distress, adding floors to an existing building is dangerous without immediate repair.

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Phase 2: Load Analysis (Column & Beam Size)

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If the building appears visually healthy, the next step involves calculation. The physical dimensions of existing structural members are measured to determine their capacity.

• Column Analysis: Mapping the grid to check column size. A 9"x9" column is often sufficient for a ground floor but may fail under the buckling load of a second story.
• Beam Depth: Verifying if the plinth beams and roof beams are deep enough to transfer the new load to the foundation.
• Load Calculation: The Total Expected Load (Dead Load of new concrete + Live Load of future occupants) is calculated and compared against the Safe Bearing Capacity of the existing columns.

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Phase 3: NDT Testing (Advanced Diagnostics)

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Note: This step is performed only if required.

If original structural drawings are missing, or if concrete quality is questionable during the visual check, Non-Destructive Testing (NDT) is used to assess the concrete without damaging it.

• Rebound Hammer Test: Estimates the compressive strength of the old concrete (e.g., determining if it is M20 grade or weaker).
• Ultrasonic Pulse Velocity (UPV): Detects internal honeycombs or hidden voids inside the beams.
• Rebar Scanning: Locates the position and diameter of the steel bars inside sealed columns.

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Phase 4: The Verdict – Go or Strengthen?

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Based on the Inspection and Analysis, the process leads to one of two conclusions:

Scenario A: Structure is Safe → Proceed

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The analysis confirms the columns, beams, and foundation have surplus capacity.

• Outcome: The building is deemed structurally stable for expansion.
• Next Step: The project can proceed safely with adding a floor.

Scenario B: Structure is Insufficient → Strengthen (Retrofit)

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The analysis shows the new load exceeds the safe limit of the current structure. This does not mean construction is impossible; it means the skeleton must be upgraded first.

• Foundation Strengthening: Widening the footing area to spread the load over more soil.
• Column & Beam Jacketing: Wrapping existing members in a high-strength concrete "jacket" with additional steel reinforcement. This increases their size (e.g., turning a 9x9 column into a 12x12 column) and load capacity.
• Result: Once strengthened, the building is certified as safe for the addition.