Delamination

ASCC's glossary states it plainly: "Separation of a coating or topping from a substrate or the layers of a coating from each other due to poor adhesion."

The two halves put the break in different places. A coating separating from its substrate has lost its bond to the pavers or concrete underneath. Layers separating from each other puts the break between coats, which can only happen on a surface carrying more than one coat.

Delamination names that loss of grip, and Euclid Chemical's account of a concrete sealer shows it can be present before anything comes loose. The visible defect that can follow, with sheets or large flakes coming away, is a separate glossary entry: peeling.

Euclid Chemical, writing about concrete sealers, describes one way that loss of adhesion develops, without using the word delamination: moisture caught under heavy or built-up coats until the sealer lets go of the concrete, the sequence set out in full under why a paver sealer peels. Before anything peels, it can show as white: "the trapped moisture and air under the debonded sealer has a refractive index such that the sealer appears white to the human eye."

ASCC, writing about decorative concrete sealers, names separation between the layers of sealer as one cause of a sealer turning yellow, and says that separation "will act and appear almost identically to some of the adhesion issues." Its prevention points at moisture caught between coats: "be sure the surface is thoroughly clean and dry prior to resealing to ensure moisture is not trapped between layers, causing adhesion failures." Yellowing is covered at does paver sealer turn yellow.