Plasterkipsis

Plasterkipsis is a term used in architecture and conservation to describe the progressive failure pattern of plaster coatings characterized by localized debonding and microcracking, often accompanied by flaking of the outer surface.

Origin and usage: The term combines plaster with the suffix -kipsis derived from Greek, used in technical vocabulary to denote a condition or process. It has appeared in conservation literature since the late 20th century as a descriptor for plaster-related deterioration phenomena.

Cause and mechanism: Moisture intrusion from rising damp or water ingress causes capillary rise within plaster layers. Water carries soluble salts that crystallize upon drying, generating crystallization pressure within pores, which leads to microcracks and detached patches; differential movement between plaster and substrate under thermal cycles and mechanical stress accelerates the process. The effect is more pronounced in lime-based plasters and renderings with poor pore structure or inadequate damp control.

Typical contexts: Historic buildings with lime plaster, plaster-on-brick or plaster-on-lath systems, basements, and façades exposed to moisture; more common where damp-proofing measures are absent or compromised.

Diagnosis and management: Diagnostics rely on visual inspection, moisture mapping, salt analysis, and non-destructive testing; treatment focuses on moisture control, breathable lime-based repair mortars, careful consolidation, and avoiding non-breathable coatings; sometimes mechanical removal of severely affected layers followed by reinstatement with compatible plaster.

Prognosis and research: In practice, plasterkipsis recognition informs conservation planning, as it signals ongoing moisture movement. Ongoing research in materials science and conservation ethics aims to improve diagnostic methods and develop compatible repair materials to minimize future recurrence.