Concrete GPR Scanning & Core Drilling Subsurface SLA

Contractor deploys calibrated high-frequency Ground Penetrating Radar (1.6 GHz–2.7 GHz) for structural mapping alongside electromagnetic passive/active line locators (50/60 Hz and 8 kHz/33 kHz induction) to detect both metallic rebar/tendons and non-metallic PVC conduits with live electrical current.

All identified post-tension cables and structural steel tendons are marked directly on the concrete slab surface in semi-permanent paint/crayon. Contractor establishes a mandatory minimum two-inch (2") radial clear boundary around all PT tendons. Drilling through marked exclusion zones is strictly prohibited without written Structural Engineer of Record (SEOR) approval.

Client acknowledges that radar signals cannot penetrate through continuous bottom steel pan decking (stay-in-place metal form decks). Embedments located tightly inside pan flutes or directly beneath dense top-mat rebar shadows may exhibit reduced reflection amplitude.

When performing diamond core drilling, Contractor utilizes auto-clamping wet vacuum rings and HEPA industrial slurry extractors to capture cooling water and concrete fines, preventing water damage to lower tenant spaces and finished flooring.

Contractor maintains $2,000,000 Professional Errors & Omissions (E&O) and $5,000,000 Commercial General Liability insurance. Client indemnifies Contractor for unlocated utilities resulting from unannounced layout revisions executed outside Contractor’s scanned grid boundaries.