Field & trade terms
Honeycomb
Also called: honeycombing, rock pockets
Honeycomb is the coarse, voided texture that appears in hardened concrete when the mortar paste failed to fill in around the stone — leaving a rough, pitted surface that looks like the cells of a honeycomb, with aggregate exposed and gaps between the pieces. It is a placement and consolidation defect: the concrete was not vibrated enough, the mix was too stiff, the reinforcement was too congested for the concrete to flow through, or it dropped too far and segregated on the way down.
Why it matters
Honeycomb is not just ugly concrete — those voids mean reduced section, a path for water to reach the reinforcement, and lower strength right where the concrete looks the worst. When it exposes rebar, it removes the cover the steel needs and sets up the same corrosion-and-spalling cycle that thin cover causes.
It is also a read on how the pour went. Honeycomb concentrated at congested reinforcement or at the base of a wall tells you the mix, the drop or the vibration was wrong, which is worth fixing before the next placement repeats it.
How it shows up on site
Voided, aggregate-exposed areas found at form strip, photographed and assessed for depth and whether reinforcement is exposed, then written up for repair — and the placement practice that caused it corrected before the next pour.
Standards it's verified against
Checklists that put honeycomb to work
Free, field-ready checklists, each with the photo every item needs before it can be submitted.
Related terms
- SlumpA measure of fresh concrete's consistency — how far a molded cone of concrete sags when the cone is lifted — used to check the mix at delivery.
- Concrete coverThe thickness of concrete between the reinforcing steel and the surface — the protective layer that keeps rebar from corroding and fire from reaching it.
- SpallingConcrete or masonry breaking, flaking or chipping off the surface — often driven by corroding reinforcement, freeze-thaw or poor placement.
- DefectA flaw in materials or workmanship that makes the work fall short of what was specified or of accepted trade practice.
- MEP (mechanical, electrical, plumbing)The mechanical, electrical and plumbing trades — the systems run through a building's structure that get inspected at rough-in and again at final.
- FirestoppingSealing openings where pipe, conduit or cable pass through a fire-rated wall or floor so the assembly's rating is restored.
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.