Building Visual Inspection (Structural Survey)
A practical, site-ready guide to inspect beams, columns, slabs, walls, and foundations for cracks, spalling, honeycombing, deformation, leakage, corrosion, and other distress signs.
1) What is a Structural Visual Inspection?
A structural visual inspection is a systematic survey of all structural elements to find visible defects and evaluate risk. It does not replace structural analysis, but it is the fastest way to identify locations that need urgent repair or further testing.
2) Preparation Before Site Visit Tools + documents
- Structural drawings
- Architectural drawings
- Previous inspection reports
- Repair/maintenance history
- Material tests (concrete/steel) if any
- Camera/phone (clear photos)
- Measuring tape / laser
- Crack gauge or ruler (mm)
- Flashlight
- Small hammer (sound test for delamination)
- Marker/chalk (mark crack location)
- Level/plumb (deformation)
3) Walk-Through Survey (General Condition) Outside → inside
- Start outside: check overall building alignment and drainage.
- Move inside floor by floor: identify major distress zones first.
- Mark defect locations on a simple floor sketch (grid / room name).
- Take photos: one wide shot + one close-up with scale.
4) Element-by-Element Inspection Columns, beams, slabs, walls, footings
A) Columns
- Cracks: vertical / diagonal / horizontal
- Spalling: cover concrete broken, rebar visible
- Honeycombing: voids from poor vibration
- Corrosion: rust stains, exposed bars
- Deformation: out-of-plumb / bulging
B) Beams
- Flexural cracks: mostly vertical at midspan (bottom zone)
- Shear cracks: diagonal near supports
- Deflection: visible sagging
- Spalling: soffit cover falling
- Leakage: stains along beam line
C) Slabs
- Map cracks (shrinkage), long cracks (bending)
- Punching zone around columns
- Deflection: ponding water / sag
- Leakage: ceiling stains, mold
- Spalling at slab soffit
D) Walls & Shear Walls
- Vertical cracks: settlement or shrinkage
- Diagonal cracks: shear / movement
- Step cracks (masonry)
- Bulging: wall bowing
- Leakage: dampness, paint peeling
E) Footings / Foundations
- Settlement signs: door/window misalignment, floor uneven
- Soil erosion: washout near foundation
- Water ponding: drainage problems
F) Stairs
- Cracks at landing
- Separation between stair and slab
- Edge spalling
- Corrosion stains at soffit
5) Defect Identification Guide
Cracks: record direction + width + length + pattern.
Spalling: cover concrete loss; urgent if rebar is exposed.
Honeycombing: voids/cavities from poor compaction.
Deformation: sagging, tilt, out-of-plumb, uneven floor.
Water leakage: stains, mold, peeling paint; accelerates corrosion.
Corrosion: rust stains, rebar exposure, cracking along rebar lines.
6) Crack Width & Severity Classification Simple field guideline
| Crack Width | Classification | Meaning | Action |
|---|---|---|---|
| < 0.2 mm | Minor | Usually shrinkage / temperature | Monitor / seal if needed |
| 0.2 – 0.5 mm | Moderate | Possible movement or service stress | Repair plan + monitoring |
| > 0.5 mm | Severe | Structural concern | Engineer review + urgent repair |
| > 1.0 mm | Critical | High risk / instability possible | Stop work + safety action |
7) Ready-to-Use Inspection Checklist Table (For Your Report) Copy into your log or Excel
| No | Element Type | Element ID / Grid | Floor | Location | Defect Type | Crack Dir. | Width (mm) | Length (m) | Spalling | Honeycomb | Corrosion | Leakage | Deform. | Severity | Photo | Possible Cause | Recommended Action | Status |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | Column | C1 (Grid A-1) | Ground | Front | Crack | Vertical | 0.3 | 1.2 | N | N | N | N | N | Moderate | P01 | Shrinkage / load | Monitor + epoxy injection | Open |
| 2 | Beam | B3 (Grid A-2) | 1st | Living room | Crack | Diagonal | 0.6 | 1.5 | N | N | N | N | Y | Severe | P02 | Shear stress | Structural review + jacketing | Open |
| 3 | Slab | S2 | Roof | Toilet | Water leakage | — | — | — | N | N | N | Y | N | Moderate | P03 | Waterproof failure | Waterproof repair | Open |
8) Repair Recommendation Library (Quick Reference) Common defects → fixes
| Defect | Common Cause | Recommended Repair |
|---|---|---|
| Hairline crack | Shrinkage / temperature | Sealant / monitor |
| Crack 0.3–0.8 mm | Movement / load | Epoxy injection |
| Spalling | Corrosion / low cover / impact | Remove loose concrete + clean rebar + anti-rust + patch mortar |
| Honeycombing | Poor vibration / congested rebar | Chip + grout injection + repair mortar |
| Corrosion | Water ingress + carbonation | Remove cover + clean rebar + anti-corrosion coating + patch |
| Water leakage | Waterproof failure / drainage | Waterproof membrane + seal joints + improve drainage |
| Beam deflection | Overload / weak reinforcement | Strengthening (steel plate / FRP / jacketing) |
| Column distress | Overload / poor detailing | RC jacketing / steel jacketing |
| Settlement | Weak soil / erosion | Soil investigation + underpinning + drainage improvement |
9) Photo Log Template Track your evidence
| Photo No. | Date | Element | Floor | Description | Taken by |
|---|---|---|---|---|---|
| P01 | — | Column C1 | Ground | Vertical crack 0.3mm, length 1.2m | — |
| P02 | — | Beam B3 | 1st | Diagonal crack near support, width 0.6mm | — |
| P03 | — | Roof Slab | Roof | Leakage stains at toilet ceiling | — |
10) Conclusion & Recommendation (Report Template)
Conclusion: The building was visually inspected for structural defects (cracking, spalling, honeycombing, corrosion, deformation, and leakage). All observed defects were recorded with location, measurements, severity classification, and photo evidence.
Recommendations:
- Repair cracks > 0.3 mm using appropriate method (often epoxy injection).
- Repair spalling immediately to prevent reinforcement corrosion.
- Fix waterproofing/drainage to stop recurring leakage and corrosion.
- For severe/critical defects, perform further testing (rebar scan, rebound hammer, core test) and structural evaluation.
Quick Site Checklist (Print Friendly)
Columns: ☐ cracks ☐ spalling ☐ honeycomb ☐ corrosion ☐ deformation
Beams: ☐ midspan crack ☐ diagonal crack ☐ sagging ☐ spalling ☐ leakage
Slabs: ☐ map cracks ☐ punching crack ☐ deflection ☐ leakage ☐ stains
Walls: ☐ diagonal crack ☐ step crack ☐ bulging ☐ dampness
Foundation: ☐ settlement ☐ uneven floor ☐ erosion ☐ ponding water
Stairs: ☐ landing crack ☐ separation ☐ edge spalling ☐ corrosion