Flagship 01 · Pre-pour structural
The last hour the steel is still visible
Pre-Pour Structural Verification. Formwork dimensions, slab thickness, bar size, spacing, cover, laps, chairs, embeds, anchor bolts and every sleeve — measured in blue laser from the drone and differenced against the structural drawings while a fix is still one ironworker and twenty minutes.
The system
Plans → scan → discrepancy engine → report
Plans / BIM
Structural drawings, the rebar schedule and the embed plan load as the reference model.
Scan
One multi-sensor flight walks the deck: LiDAR geometry plus high-res RGB down into every mat.
Computer vision
Bars detected and sized, spacing and cover measured, embeds and sleeves indexed.
Discrepancy engine
Every measured value differenced against spec; only exceptions reach a human.
Embeds · anchor bolts · sleeves
A bolt pattern is cheap to move and brutal to relocate
The drone indexes every embedded item on the deck against the embed plan: plate location and orientation, anchor bolt pattern and bolt-circle diameter, thread projection above the finished slab, and each sleeve or block-out by size and position. Anything present on the deck but absent from the drawings is flagged as hard as anything missing.
- PlatesLocation, rotation, elevation
- Anchor boltsPattern, spacing, projection
- SleevesDiameter and position
- Block-outsSize vs the opening schedule
- ExtrasUnplanned items flagged too
Cost of not catching it
A misplaced anchor bolt group found before the pour is a carpenter moving a template. The same group found after the steel arrives is core drilling, epoxy anchors, an engineer's repair detail and a crane sitting idle — and it lands squarely in the rework column that costs US construction roughly $65B a year.
Coverage
Every pre-pour check, and the sensor that makes it
| Inspection | What is verified | Sensor |
|---|---|---|
| Formwork dimensions | Slab and footing plan dimensions, edge lines, blockout sizes | LiDAR + photogrammetry |
| Formwork alignment | Forms square, plumb and on the gridline before pour | LiDAR tied to site control |
| Slab thickness | Formed depth from soffit to screed line, point by point | LiDAR depth map |
| Rebar size | Bar diameter classified off the deformation pattern | High-res RGB + computer vision |
| Rebar spacing | Centre-to-centre in both mat directions, top and bottom | RGB + measurement |
| Rebar cover | Clear distance from steel to the form face and top of pour | LiDAR + RGB |
| Lap splices | Splice length at every bar overlap | RGB + measurement |
| Chair / support height | Top mat held at the specified elevation | LiDAR profile |
| Embeds & plates | Location, orientation and elevation of embedded plates | LiDAR + RGB |
| Anchor bolts | Bolt pattern, projection, spacing and bolt-circle diameter | LiDAR + RGB |
| Sleeves & block-outs | Every penetration present, sized and positioned | LiDAR + BIM comparison |
| Post-tension layout | Tendon profile and support heights where used | RGB + profile scan |
| Vapor barrier | Coverage and lap continuity under the slab | High-resolution RGB |
| Pour volume | Formed volume less steel displacement, for the order | LiDAR volumetric |
Sample output
The exception list your super gets before the pump arrives
| Location | Checked item | Spec | Drone measured | Status |
|---|---|---|---|---|
| Deck 3 · Bay C4 | Top mat spacing | 12" O.C. each way | 15½" O.C. east-west | Fix now |
| Deck 3 · Edge E | Clear cover to form face | 1½" | ¾" over 9 ft | Fix now |
| Col. line B | Anchor bolt projection | 3½" above slab | 2⅜" | Fix now |
| Deck 3 · Bay A2 | Lap splice length | 40 dᵦ (25") | 19" | Fix now |
| Blockout 12 | Sleeve position | Grid B + 4'-0" | Grid B + 4'-1⅞" | Review |
| Deck 3 | Formed slab thickness | 8" | 8⅛" avg, 8½" at C6 | Review |
| Deck 3 · Bay D1 | Bar size, bottom mat | #5 | #5 confirmed | Pass |
Illustrative report format. Passing items are collapsed by default — the crew only sees what needs a hand on it.
Sonar · ultrasonic ranging
Laser and LiDAR are the primary measurement layer, but they lose confidence on dark, wet, dusty or mirror-like surfaces and at very short standoff. Sonar fills that gap: ultrasonic pulses resolve the small stuff — millimetre-scale gaps, offsets, thin clearances and shallow voids — in low light, through airborne dust and against surfaces a laser skips off. On this page it is what confirms cover to the form face, embed projection and the small clearances between congested bars before the pour buries them.
What you’ll receive
Pre-pour structural verification — marked-up DXF overlay on your plan + PDF exception report + supporting point cloud (LAS/E57) if a dispute ever needs the raw measurement.
Open formats only: GeoTIFF · LAS/LAZ · E57 · OBJ/FBX · DWG/DXF · LandXML · PDF · CSV. No proprietary viewer required.
What it costs when nobody's watching
Everything under the pour is priced at demolition rates.
~$65B / yr
U.S. construction rework cost — about 5% of $1.3T in total construction spend.
Source: Autodesk / FMI, Harnessing the Data Advantage in Construction (2020/2022)
5–9%
of total project cost lost to rework on a typical job; 20–30% on troubled projects.
Source: CII; Dodge Data & Analytics, SmartMarket Report on Project Rework (2018)
52%
of total cost overrun on a project traces back to rework.
Source: CII, analysis of 150+ industrial construction projects
up to 70%
of rework traces to engineering, design and coordination errors — short laps, wrong spacing, missed cover.
Source: General industry claim, repeated across rework literature — no single primary citation
~$31B / yr
rework tied to bad, missing or wrong project data reaching the field.
Source: PlanGrid / FMI, Construction Disconnected (2018)
$60.1M · 12.5 months
average U.S. construction dispute value and duration — a dated pre-pour record is the cheapest defense there is.
Source: Arcadis, 2025 Global Construction Disputes Report
Government-grade sources (BLS, OSHA, NIST/NIBS) are cited as published. Industry research (Arcadis, FMI/Autodesk, CII, NSC) is survey- and estimate-based. Vendor case studies and vendor pricing pages are labeled where used and should be read as documented examples, not industry averages.