Overview
A structural audit goes significantly beyond a visual inspection. It combines non-destructive testing (NDT) techniques — rebound hammer, ultrasonic pulse velocity, cover meter survey, half-cell potential mapping, and carbonation depth measurement — with a systematic visual survey to produce a quantified, evidence-based condition rating for every structural element in the building.
In Hyderabad's construction context, where many buildings from the 1970s–2000s were built with inadequate concrete cover (often 10–15mm vs. the IS 456:2000 minimum of 25–40mm) and higher water-cement ratios, carbonation front reaches reinforcement within 15–20 years — triggering corrosion that causes spalling, section loss, and eventually structural inadequacy. A structured audit identifies which elements have reached this threshold and which are still in the safe zone, allowing prioritised repair investment.
Prisci Constructions produces audit reports to IS 13311 and BIS standards, with each NDT technique documented per element. Reports include a traffic-light condition rating (Good / Fair / Poor / Critical) for every column, beam, slab, and wall surveyed, plus a prioritised repair cost estimate.
- IS 13311 Compliant NDTRebound hammer, UPV, and half-cell tests conducted per IS 13311 Part 1 & 2 standards.
- Element-by-Element RatingEvery column, beam, and slab individually assessed and assigned a condition rating — not a building-wide average.
- Prioritised Repair Cost EstimateAudit report includes a phased repair cost estimate so the client can budget and prioritise without commissioning a separate quantity survey.
- Accepted by InstitutionsAudit reports accepted by MES, HPCL, SAAP, municipal bodies, and banks for rehabilitation loan applications.
Common Problems We Solve
- Building owner unsure whether spalling and cracking visible in a 25+ year old structure requires urgent repair or routine maintenance
- Institutional client (defence, government) requiring a formal condition report before approving a rehabilitation budget
- Property buyer wanting an independent structural assessment before purchasing an older commercial or residential building
- Dispute between a building owner and a contractor about whether previous repair work was adequate
- Insurance claim requiring a third-party structural condition assessment to justify repair cost quantum
- Post-earthquake or post-fire assessment to determine which elements remain safe for continued occupation
Root Causes
- Concrete carbonation advancing through insufficient cover to reinforcement level — the commonest cause of structural deterioration in Hyderabad's building stock
- Chloride contamination in coastal or industrial environments driving accelerated corrosion at rebar level
- Original design or construction deficiency — understrength concrete, insufficient reinforcement, missing stirrups
- Cumulative deferred maintenance — minor repairs not attended to for 10+ years, allowing deterioration to compound
- Structural modification without engineering approval — removal of walls, addition of floors, change of use increasing loads
- Earthquake or differential settlement loading creating residual stress states beyond the original design assumptions
Our Approach
A systematic element-by-element survey is conducted using a combination of NDT instruments. Test results are recorded on element location drawings. Each structural element is assigned a preliminary condition rating based on NDT data. Areas requiring more detailed investigation (core drilling, half-cell mapping) are identified during this phase.
The audit report is structured to serve the client's purpose — institutional reports follow the brief from MES or SAAP; pre-purchase due-diligence reports focus on risk and cost; rehabilitation planning reports include phased repair programmes. The report format is agreed with the client before fieldwork commences.
Fieldwork is conducted over 1–3 days depending on building size. NDT equipment is calibrated before use. Test results are recorded digitally on location plans. The written report is issued within 7–10 working days of fieldwork completion, including all test result data tables, annotated photographs, and recommendations.
Materials Used
A structural audit is conducted with calibrated NDT instruments — listed below are the instruments deployed and the core sampling consumables required for laboratory-verified testing where NDT findings require confirmation.
Our Process
Pre-Audit Document Review
Original building drawings (architectural and structural), completion certificates, soil investigation reports, and any previous inspection or repair records are reviewed before the site visit. Where drawings are unavailable, an as-built sketch is prepared during the site survey. Understanding the original design intent is essential for interpreting NDT readings correctly.
Visual Survey & Defect Mapping
A comprehensive visual survey of all accessible structural elements is conducted. Spalling, cracking, corrosion staining, deflection, and misalignment are noted on elevation drawings. Defect severity is classified (minor, moderate, severe, critical) based on BIS guidelines. This forms the basis for prioritising NDT test locations.
Non-Destructive Testing (NDT)
Rebound hammer tests at a 200mm grid on all columns, beams, and slab soffits (minimum 9 readings per element, converted to estimated compressive strength per IS 13311 Part 2). UPV testing to assess concrete quality and detect internal voids or delaminations. Covermeter survey to map concrete cover to reinforcement on 10% of elements per floor. Half-cell potential mapping on elements showing corrosion staining.
Carbonation & Chloride Testing
Core samples (50mm diameter) are extracted at locations identified by NDT as potentially carbonated. Freshly broken cores are sprayed with phenolphthalein indicator solution — colourless zones (pH below 9) indicate carbonated concrete. Carbonation depth is measured and compared to rebar cover to determine whether the reinforcement is at risk. Chloride extraction testing is conducted on cores in coastal or industrial locations.
Condition Rating & Report Preparation
All data — visual survey, NDT readings, carbonation depths — is compiled and each structural element is assigned a condition rating (Good: no significant defects; Fair: minor defects, monitor; Poor: repair recommended; Critical: urgent repair or load restriction required). The full audit report includes data tables, annotated photographs, condition rating drawings, and a prioritised repair cost estimate.
Report Presentation & Follow-Up
The audit report is presented to the client's engineering or management team — not simply emailed — to explain findings and answer questions. For institutional clients (MES, HPCL, SAAP), the report is formatted to the client's specified standard. A 12-month follow-up monitoring visit is available to confirm that deterioration has not progressed in elements rated Fair.
Frequently Asked Questions
Related Projects
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