Raft Rebar Horizontal Inspection Checklist

Definition: Inspect raft rebar (horizontal) checklist for site engineers ensures correct cover, bar sizes, laps, spacing, openings, and embeds before concrete, preventing defects and costly rework.

Verify cover, sizes, laps, spacing, openings, and embeds.
Prevent corrosion, clashes, delays, costly rework, and nonconformances.
Measure, tag, photograph, and record evidence against approved drawings.
Interactive, commentable checklist with export and QR code traceability.

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Checklist

Inspect raft rebar (horizontal) sets a precise, pre-concrete scope for site engineers and inspectors to validate raft slab reinforcement before any pour. This focused foundation mat rebar QA process checks cover, bar sizes, lap splices, spacing, openings, and embedded items. By keeping the scope horizontal only (excluding vertical elements and any pouring activities), you reduce corrosion risk, honeycombing, congestion, and MEP clashes that drive rework and schedule slippage. The checklist emphasizes measurable methods—tape, caliper, cover meter, and total station—plus photographic evidence and approval references per approved project specifications and authority requirements. You’ll confirm stability under foot traffic, tidy laps and couplers, correct reinforcement around blockouts, and proper positioning of sleeves, plates, and starter bars at construction joints. The result is a documented, buildable raft rebar layout with traceable sign-offs. Use the interactive features to tick items, add comments with photos, and export your report as PDF or Excel complete with a secure QR code.

Confirm rebar size, grade, and spacing against approved shop drawings and bar bending schedules using calipers and tape measurements. Validate cover with cover meters and spacer heights, and record all readings with time-stamped photos and drawing references for traceable compliance.
Control lap splices, anchorage, and couplers with measurable checks: tape lap lengths, verify tie patterns, and record coupler model, lot, and torque. Ensure laps are staggered and free from clustering to avoid congestion and maintain structural continuity around edges and corners.
Coordinate openings, blockouts, and MEP conduits early. Verify locations by total station, maintain required cover on all sides, and install additional trimmer and U-bars as detailed. Prevent unauthorized bar cutting by logging approvals and photographing every trimmed or re-anchored bar.
Interactive online checklist with tick, comment, and export features secured by QR code.

Pre-Inspection & Documentation

1. Verify latest approved IFC drawings and bar bending schedules are on hand; cross-check revision numbers and dates against document control. Acceptance: current revisions only. Evidence: photos of title blocks and inspector initials.
2. Confirm specified concrete cover for bottom, top, and edges per approved project specifications and authority requirements. Record target values for each zone. Evidence: note values on drawing snapshot and sign.
3. Check blinding level and grid setout at raft area using auto level and tape. Acceptance: level within ±5 mm, grid line offset within ±10 mm. Evidence: instrument readings and marked grid photos.

Rebar Identification & Sizes

4. Confirm bar grade and diameter for each mark using caliper/micrometer and mill tags. Acceptance: diameter within manufacturer tolerance; grade matches schedule. Evidence: close-up photos of tags and readings.
5. Randomly sample 10% of cut/bent bars for length and shape versus bending schedule using tape and template. Acceptance: dimensions match schedule. Evidence: measured photos with tape visible.
6. Verify top and bottom mat bar marks are correctly placed by grid/bay as per drawings. Method: count and compare sequence to layout. Acceptance: no mark substitutions. Evidence: annotated plan and photos.
7. Check epoxy-coated or stainless bars (if specified) at aggressive exposure zones/penetrations. Acceptance: coating intact, no damage or bare steel; repair per manufacturer if needed. Evidence: macro photos of coatings.

Cover, Supports & Stability

8. Confirm approved spacer/chair type, size, and material match submittal. Acceptance: spacer dimension provides required cover; materials compatible with concrete. Evidence: product labels and submittal reference.
9. Measure bottom cover at representative grid intersections using cover meter or feeler blocks. Acceptance: within specified cover ±5 mm. Evidence: logged readings and photo at each test point.
10. Check chair heights and support rails for top mat. Acceptance: resultant top cover within ±5 mm of specified. Evidence: tape readings from top bar to formwork reference.
11. Verify chair spacing and distribution (lines and at crossings) to prevent sagging. Acceptance: spacing per submittal; bars remain level. Evidence: photos with measured spacings.
12. Assess mat stability under foot traffic by gentle load test. Acceptance: no bar displacement >5 mm; supports remain seated. Evidence: inspector note and photos before/after.

Laps, Anchorage & Couplers

13. Measure lap splice lengths for bottom mat primary bars with tape. Acceptance: not less than scheduled lap; negative tolerance not permitted. Evidence: photos showing tape and bar IDs.
14. Confirm lap locations are staggered and not clustered in one section. Acceptance: staggering per drawings; avoid adjacent laps aligning. Evidence: annotated plan and overview photos.
15. Verify lap tying: double wire at ends and at mid-length. Acceptance: minimum three secure ties per lap. Evidence: close-up photos of ties.
16. Check hooks/anchorage at slab edges, corners, pits, and terminations. Acceptance: bend shape and extensions per details. Evidence: photos with ruler at bends.
17. Inspect mechanical couplers (if used): model, position, and tightening per manufacturer. Acceptance: correct type; torque recorded; lot numbers captured. Evidence: torque sheet and coupler tag photos.

Spacing, Openings & Blockouts

18. Measure bar spacing for top and bottom mats using tape across multiple bays. Acceptance: within ±10 mm of specified spacing. Evidence: photos with tape and grid references.
19. Confirm additional reinforcement around columns/walls (bands/strips) per details. Acceptance: sizes, quantities, and extents match drawings. Evidence: marked-up plan and photos.
20. Verify continuity bars across planned construction joints in raft. Acceptance: projection length and cover per detail; caps if exposed. Evidence: measurement photos and detail reference.
21. Set out openings and blockouts by total station or tape from grid. Acceptance: location within ±10 mm; size within ±5 mm. Evidence: survey screenshots and tagged photos.
22. Inspect any bar trimming at openings. Acceptance: trimming only where permitted; re-anchorage provided per detail; approval recorded. Evidence: approval reference and close-ups.
23. Check trimmer, U-bars, and diagonal bars around openings. Acceptance: installed as detailed; correct lap/anchorage. Evidence: count sheet and photos with rulers.

Embeds, Cleanliness & Handover

24. Position embed plates, anchor bolts, and shear keys using total station. Acceptance: plan ±10 mm; level ±5 mm; orientation per drawing. Evidence: survey report and photos.
25. Secure MEP conduits and sleeves to reinforcement without reducing required cover. Acceptance: ties installed; clear cover maintained all sides. Evidence: measured photos and tie points.
26. Prohibit unapproved welding to rebar. If specified, verify WPS, welder approvals, and locations. Acceptance: approvals attached; welds only where detailed. Evidence: approval copies and weld photos.
27. Clean reinforcement and blinding: remove mud, oil, loose scale, tie wire cuttings. Acceptance: surfaces clean and dry. Evidence: area-wide photos before sign-off.
28. Protect reinforcement from precipitation and contaminants with covers or tarps as needed. Acceptance: no standing water or debris accumulation. Evidence: protection photos and weather note.
29. Complete final walkdown with foreman and engineer; close all observations/NCRs. Acceptance: all checklist items ticked; sign-offs captured. Evidence: digital signatures and QR-tagged report export.

What a horizontal raft rebar inspection covers and why it matters

A horizontal raft rebar inspection focuses strictly on the raft slab reinforcement before any concrete placement. Inspectors validate bar grades, diameters, and placement across top and bottom mats, then confirm concrete cover using spacers, chairs, and cover meters. Lap splices, hooks, and couplers are verified for length, positioning, and fixation, while bar spacing is measured across multiple bays for consistency. Openings and blockouts receive particular attention: authorized trimming, trimmer/U-bars, and re-anchorage are compared to details to maintain load paths. Embedded items, sleeves, and conduits are set out and tied so they do not compromise cover or cause clashes. Cleanliness and mat stability checks help prevent voids, segregation, and corrosion initiators. By capturing photos, measurements, and approval references per approved project specifications and authority requirements, teams create a defensible, repeatable quality record that reduces rework and schedule risk on deep foundations.

Confirms cover, spacing, laps, and bar sizes pre-concrete.
Prevents clashes and preserves required concrete cover.
Documents evidence with measurements and photos.
Keeps scope horizontal only; excludes pouring operations.
Improves buildability and reduces rework risk.

Methods, tolerances, and practical cues you can rely on

Use a caliper to verify diameters on representative samples and photograph mill tags for traceability. Tape measures confirm spacing, lap splice lengths, and bar projections at construction joints; aim for consistent readings within the stated tolerances and project details. A cover meter or feeler blocks validate bottom cover at grid intersections and along edges, while chair height checks indicate top cover control. Where mechanical couplers are specified, record model, lot numbers, and torque values per manufacturer literature. For openings and penetrations, set out with a total station and log as-built coordinates to control location and size tolerances. Stability is equally important: distribute chairs and ties so mats don’t shift under foot traffic. Finally, ensure cleanliness—no mud, oils, or loose scale—so the bond interface remains reliable. These techniques create clear acceptance cues visible to the crew and verifiable during sign-off.

Measure, photograph, and annotate against drawings.
Use cover meters and chair height checks.
Record torque and lot numbers for couplers.
Survey openings for location and size control.
Verify stability under typical foot traffic.

Coordinating openings, embeds, and MEP without losing cover

Openings and embedded items can quickly erode required cover or disrupt reinforcement continuity if left to late-stage coordination. Begin by extracting an opening and embed register from the latest drawings, then walk the mat to verify each location with a total station or grid-based offsets. Check that sleeves, conduits, plates, and anchor bolts are tied in place without displacing bars and that required cover is still achieved on all sides. If trimming is authorized, confirm re-anchorage or added trimmer/U-bars exactly as detailed, and capture the approval reference in your report. Keep couplers, laps, and hooks away from congested zones around penetrations to preserve bar spacing and allow concrete flow. A photo-rich, measurement-backed record limits disputes and prevents late clashes with MEP, while ensuring the raft remains buildable and structurally sound.

Start from an updated opening and embed register.
Survey and tag each penetration location.
Maintain required cover on all sides of embeds.
Log approvals for any bar trimming.
Avoid lap clustering near congested penetrations.

How to Use This Interactive Raft Rebar Inspection Checklist

Preparation: Bring approved drawings/BBS, cover meter or feeler gauges, caliper, tape measure, auto level/total station, marking pens, camera-enabled device, and PPE (helmet, gloves, eye protection, boots, high-vis). Confirm safe access and adequate lighting.
Open the checklist app, select your project and raft area, and load current drawing revisions. Enter grid ranges, pour segment ID (if applicable), and target cover values from specifications.
Start interactive mode on mobile or tablet. Tick each item as you inspect, capturing photos and measurement readings directly into the corresponding checklist line.
Use comments to note variances, approvals, or corrective actions. Link document numbers (shop drawings, RFIs, WPS, manufacturer datasheets) to specific items for traceability.
Add geotags and grid references for openings and embeds. For couplers, enter model, lot numbers, and torque values, and attach torque sheets or calibration certificates.
When complete, generate an export as PDF/Excel with embedded photos, timestamps, and coordinates. The system will add a unique QR code for authentication.
Sign-Off: Capture digital signatures from contractor and consultant. Distribute the export to stakeholders and archive the QR-authenticated record for future audits.

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Javier Rama SeismoJavi

Feb 12, 2026

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FAQ

Question: What cover tolerances should I apply for a raft slab rebar inspection?

Follow the approved project specifications and authority requirements for target cover values. Practically, verify cover at representative grid points using a cover meter or feeler blocks, and control top cover by chair height. Record all readings with photos and grid references, and escalate any persistent shortfalls before concrete placement.

Question: How do I measure lap splices accurately on congested raft reinforcement?

Use a steel tape along the bar axis and measure from the end of one bar to the overlapping end of the adjacent bar, following the bar curvature if hooked. Mark measurement points with a marker for clarity. Compare with scheduled lap lengths, photograph the tape in place, and log the bar marks and grid location.

Question: What should I do if delivered bar sizes or grades don’t match the schedule?

Stop installation in the affected area and quarantine the mismatched bars. Document evidence with photos, tags, and measurements. Notify site management and raise an RFI or NCR as required. Replacement or a design-concession decision should reference the approved project specifications and authority requirements before work resumes.

Question: When are mechanical couplers preferable to lap splices in rafts?

Couplers are often used where laps would cause congestion, near penetrations, or where bars are short due to logistics. If couplers are specified, verify the correct model, lot numbers, and applied torque per manufacturer guidance, and photograph each installation. Keep couplers clear of highly congested zones to maintain spacing and cover.