Delamination of building materials is the unintended separation of material layers or plies of materials. In many cases, building materials are applied or installed on top of one another in a manner intended to be a permanent installation.
The photos below show examples of roof ply materials that have separated from one another due to exposure to the elements, improper installation, or deterioration related to exposure to ultraviolet rays.
The two particular examples below happened to be cases of fish mounting in modified bitumen roofing systems.
The picture below shows a different different type of dilemmation. In this case improper mortar was applied on top of a historic lime mortar joints. The improperly installed mortar has flaked off from the substrate material, this is a case of delamination. The newer improperly installed material has delaminated from the substrate.