Concrete QA/QC 2026: The “Wet Scan” & Pre-Pour Workflow

TL;DR: The “Zero Rework” Strategy

• The ROI: Correcting a high spot during the pour costs near-zero (tap it down). Grinding it down after cure costs $15/sq. ft..In vertical construction, the “Pour Cycle” is the heartbeat of the project. If the concrete stops, the job stops.
• The Problem: Traditional “10-foot straightedge” tests are inaccurate and only measure one line. They miss the “waves” that cause robot failure.
• The Risk: ACI 117 tolerances are strict. If a window wall doesn’t fit between slabs, the rework cost (grinding/filling) falls on you.
• The Solution: Pre-Pour Scanning to verify sleeves/embeds, and Wet Concrete Scanning to generate a Heat Map while the slab is still plastic.

The High Cost of “Pour and Pray”: Avoiding the $10,000 Grind

In vertical construction, the “Pour Cycle” is the heartbeat of the project. If the concrete stops, the job stops.

But speed often breeds error. A sleeve gets kicked by a boot. A post-tension cable shifts. The finishing crew leaves a “birdbath” in the middle of the slab.

By the time you find these errors with a tape measure 28 days later, it’s too late. The concrete is hard, the wall framers are waiting, and you are facing a $10,000 grinding bill.

At iScano, we believe concrete should be verified twice: once before it pours, and once while it’s wet. This is the 2026 Concrete QA/QC Workflow.

The Pre-Pour: Verifying the “Invisible”

The most expensive rework isn’t the concrete itself; it’s what is inside or under it.

1. Embed & Sleeve Verification

Before the trucks arrive, the deck is a chaotic web of rebar, MEP sleeves, and Nelson studs.

• The Old Way: A field engineer spot-checks 10% of the sleeves with a tape measure.
• The Scan Way: We scan the entire deck with a Terrestrial Laser Scanner. We overlay the BIM model to verify 100% of sleeves are within the specified tolerance.
• The ROI: Finding one missing conduit sleeve avoids the need to X-Ray and core-drill the slab later—a saving of roughly $2,000 per hole.

2. Post-Tension (PT) Cable Mapping

Drilling into a PT cable is catastrophic. It creates a “bomb” inside the slab that can compromise the building’s structural integrity.

• The Workflow: We scan the cables before the pour creates a permanent “X-Ray” record. If a tenant needs to drill a new drain line 5 years from now, you know exactly where the cables are, avoiding a $50,000+ structural repair.

The “Wet Scan”: Real-Time Flatness (FF/FL)

Standard Floor Flatness (FF) and Floor Levelness (FL) reports are typically done the next day. But why wait until the concrete is hard?

The “Heat Map” Advantage

Using active laser scanning during the finishing process (while the concrete is still plastic) allows for real-time correction.

• The Process: As the finishing crew works, we scan the surface.
• The Output: We deliver a color-coded Heat Map the foreman can review on a tablet.
  • Red: High spot (Needs a screed pass).
  • Blue: Low spot (Needs more mud).
• The Result: You achieve “Super Flat” specs (FF 50+) without the guesswork. Correcting a wave while the concrete is wet costs minimal labor time. Correcting it later requires expensive diamond grinding or self-leveling compound.

The ACI 117 Conflict: Windows vs. Slabs

A major source of litigation in 2026 is the interface between the concrete structure and the Curtain Wall (Glass Facade).

• The Concrete Rule (ACI 117): ACI 117 commonly allows a slab surface elevation tolerance on the order of ±3/4 inch in typical scenarios, unless the project specifies tighter requirements.
• The Glass Rule: Curtain wall anchors often have a vertical adjustment of only ±1/2 inch.

The Conflict: If your slab is legally “within tolerance” (low by 3/4 inch) but the glass anchor runs out of adjustment, the glazier cannot install the window. Who pays?

• Without a Scan: The arguments drag on for weeks.
• With a Scan: You have an As-Built Map showing the edge-of-slab elevation every 6 inches. You can identify the problem spots immediately and order custom shims before the glass trucks arrive, keeping the schedule moving.

The Financial Argument: Rework vs. ROI

Construction rework accounts for 4-9% of total project cost. On a $20M concrete package, that is nearly $1 Million in lost margin.

Cost Comparison:

Defect Type	Cost to Fix (Post-Cure)	Cost to Fix (With Scanning)
Missed Sleeve	$2,000 (X-Ray + Coring)	Minimal (Move it before pour)
High Spot (FF Failure)	$15/sq. ft. (Grinding)	Minimal (Re-screed while wet)
Edge of Slab Deviation	$50,000 (Delay + Rework)	$500 (Custom Shims)

FAQ: Concrete Scanning

Conclusion: Pour with Confidence

Concrete is unforgiving. Once it sets, your mistakes are cast in stone.

Don’t rely on a spot-check. Use 3D Laser Scanning to verify your deck before the pour and map your flatness while you can still fix it. In 2026, the most profitable concrete contractors don’t just pour; they prove.

Ready to eliminate back-charges? Contact us today to schedule your Pre-Pour Verification.

References

1. ACI Committee 117. (2010). Specification for Tolerances for Concrete Construction and Materials (ACI 117-10).
2. American Concrete Institute. (2022). The Floor Flatness Report (ACI Committee E702).
3. ASCC. (2018). Position Statement #24: Tolerances for Suspended Concrete Slabs.
4. Autodesk / FMI. (2022). Harnessing the Data Advantage in Construction (Rework Statistics).