Field & trade terms
Delamination
Also called: delaminating, debonding
Delamination is the loss of bond between layers that were meant to act as one — a coating lifting off its substrate, a floor topping separating from the slab, the plies of a roofing or waterproofing membrane pulling apart, or a finish releasing from what it was applied to. The separated layer often still looks intact from the surface, but it sounds hollow when tapped and has lost the adhesion the assembly depends on. The usual causes are surface prep that was skipped, contamination or moisture at the bond line, or a product applied outside its conditions.
Why it matters
A delaminated layer is a failure waiting to progress. A coating that has let go will keep peeling, a topping that has debonded will crack and lift under traffic, and a membrane whose plies have separated has lost the continuity that made it waterproof. The layer that looks fine is exactly the trap — the failure is at the plane you cannot see.
Almost all of it traces back to the bond line: dirty, damp or unprofiled substrate, or a product forced on in the wrong conditions. That makes surface prep and conditions the thing to verify before the layer goes down, not after it fails.
How it shows up on site
Hollow-sounding areas found by sounding a coating, topping or membrane, mapped and photographed, and the debonded material removed and reworked — with the substrate prep and conditions checked so the replacement actually bonds.
Standards it's verified against
Checklists that put delamination to work
Free, field-ready checklists, each with the photo every item needs before it can be submitted.
Related terms
- SpallingConcrete or masonry breaking, flaking or chipping off the surface — often driven by corroding reinforcement, freeze-thaw or poor placement.
- EfflorescenceThe white, powdery salt deposit that appears on masonry or concrete when water moving through the material carries dissolved salts to the surface.
- Holiday testAn electrical test that finds pinholes, thin spots and gaps — holidays — in a protective coating or membrane that the eye would miss.
- 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.