Inspection process
Dimensional inspection
Also called: dimensional check, layout inspection, as-built measurement
Dimensional inspection is the tape-measure and instrument check: confirming that what was built sits where the drawings put it, at the right size, elevation and clearance, within the stated tolerance. It covers layout before work starts and the finished condition after — embed and anchor-bolt locations, slab elevations, opening sizes, the clearances a following trade needs. Where a visual inspection judges appearance and completeness, a dimensional inspection produces numbers that pass or fail against a tolerance.
Why it matters
A dimension caught wrong before it is built on is a quick reset; the same error found after the next trade stacks on it is a cascade. Anchor bolts set out of position, a slab poured a fraction low, an opening framed undersize — each throws off everything that follows, so the measurement is worth taking before the condition is locked in.
The numbers also settle disputes cleanly. When the acceptance criterion is a stated tolerance, a recorded measurement and a photo decide the question — the work is inside the band or it is not, without an argument about whether it looks close enough.
How it shows up on site
Layout verified against the control lines before a pour, anchor-bolt templates checked to the drawing, slab elevations shot with a level, and finished openings measured against the schedule — with the readings recorded, not just eyeballed.
Standards it's verified against
Checklists that put dimensional inspection to work
Free, field-ready checklists, each with the photo every item needs before it can be submitted.
Related terms
- ToleranceThe allowable amount a dimension or condition can vary from the target and still be acceptable — the plus-or-minus on a spec.
- Visual inspectionJudging work by direct observation against the drawings and standard — the first and most common check on any job.
- Acceptance criteriaThe stated, measurable conditions installed work has to meet before it can pass — the yardstick an inspection judges against.
- Record drawingsThe final drawing set updated to show what was actually built, including field changes, prepared for the owner at closeout.
- Hold pointA stop in the inspection and test plan where work cannot continue until a required party inspects and signs off the release.
- Witness pointA step where a party is invited to observe the work, but the crew may proceed if that party doesn't attend within the agreed notice.
Knowing the term is step one. Proving it is the job.
RTI holds the submit button until every mandatory item is answered and the photos are attached, then chains the record so it can be proven untouched later.