What is the difference between GPR and X-Ray?

GPR (Ground Penetrating Radar) uses electromagnetic pulses to scan concrete from one side — it is fast, portable, and requires no restricted area. X-Ray uses radiation to create a detailed image through the slab and requires access to both sides of the element plus a safety exclusion zone. GPR is the go-to for most field conditions; X-Ray provides higher resolution when both-side access is available.

How deep can GPR scan into concrete?

Standard GPR equipment can effectively scan concrete to depths of 16-18 inches, which covers the vast majority of structural slabs, walls, and elevated decks. Scan quality depends on concrete composition, moisture content, and reinforcement density. For thicker elements, X-Ray may be recommended.

Do I need to scan before every cut?

Scanning is strongly recommended before any cutting or coring operation, and it is required for post-tensioned structures. Even in conventionally reinforced concrete, scanning prevents accidental hits to electrical conduit, plumbing lines, and structural reinforcement that could cause safety hazards, costly repairs, or structural compromise.

Who performs the scanning?

Scanning is performed by our sister company, Concrete Imaging. Their technicians are trained and certified in both GPR and X-Ray technology. As a CTS affiliate, they integrate seamlessly into our project workflow — scan results are shared directly with our cutting and coring crews before work begins.

GPR & X-Ray Scanning

See inside concrete before you cut. Powered by our sister company, Concrete Imaging.

Know What's Inside Before You Cut

Cutting into concrete without knowing what is embedded inside is a risk no one should take. Post-tension cables under 30,000+ pounds of force. Live electrical conduit. Structural rebar. A single accidental hit can mean catastrophic failure, injury, or tens of thousands of dollars in unplanned repairs.

CTS partners with our sister company, Concrete Imaging, to provide GPR and X-Ray scanning services that give our crews — and yours — a clear picture of what is inside the slab before a single blade touches concrete.

GPR

Fast, portable, one-side access

X-Ray

High-resolution, detailed imaging

Concrete Scanning

GPR vs. X-Ray

Both technologies serve the same goal — seeing inside concrete — but each has distinct advantages depending on site conditions.

Factor	GPR	X-Ray
Technology	Electromagnetic radar pulses	Radiographic imaging (radiation source)
Access Required	One side only	Both sides of the element
Setup Time	Minutes — highly portable	Longer — safety zone and film placement
Scan Depth	Up to 16-18 inches	Through full element thickness
Resolution	Good — identifies objects and approximate depth	Excellent — detailed image of all embedments
Safety Zone	None required	Exclusion zone required (radiation)
Best For	Field scanning, large areas, single-side access	High-resolution imaging, post-tension details
Speed	Fast — scan large areas quickly	Moderate — individual exposures per location

Applications

Concrete scanning supports safety and planning across a wide range of project types.

Pre-Cut Scanning

Map rebar, conduit, and post-tension cables before any cutting or coring operation to prevent accidental strikes.

Post-Tension Detection

Identify and map post-tension cables in PT slabs — cutting a cable can cause catastrophic structural failure.

Utility Location

Locate embedded electrical conduit, plumbing lines, and communication ducts within concrete elements.

Structural Assessment

Evaluate rebar spacing, cover depth, and reinforcement condition for renovation and structural analysis projects.

Slab Thickness Verification

Confirm actual slab thickness versus design documents — critical for load analysis and modification planning.

Void Detection

Identify voids, delaminations, and honeycombing within concrete structures that may indicate quality issues.

When to Use Each Method

GPR

Choose GPR When...

You only have access to one side of the element
Large areas need to be scanned quickly
The building is occupied and cannot be cleared
Slab-on-grade with no access below

X-Ray

Choose X-Ray When...

You need the highest resolution imaging available
Post-tension cable paths need precise mapping
Both sides of the element are accessible
Elevated slabs or walls with access from both sides

Frequently Asked Questions

Common questions about concrete scanning services.

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