Putzaufbau

Putzaufbau is the layered plaster system applied to the surface of walls to protect, finish, and regulate the indoor climate of a building. It is common in European construction for both interior and exterior walls, providing durability, moisture management, and a range of aesthetic finishes.

A typical Putzaufbau comprises several layers. The substrate can be masonry, concrete, or plasterboard. The base coat, or Unterputz, establishes adhesion and roughness for subsequent layers. A reinforcement layer or mesh is often embedded to control cracking and improve durability. The final coat, or Oberputz, determines texture and color and may be applied in multiple passes. Materials used include cementitious plasters (cement-based or lime-cement blends), lime-based plasters, gypsum-based plasters, or modern polymer-modified mixes. In exterior systems, the plaster may be combined with insulation boards in external thermal insulation composite systems (ETICS). Some schemes use additional scratch or smoothing coats and decorative finishes such as mineral pigments.

Application begins with substrate preparation and dampening, followed by the application of Unterputz in one or more passes. If used, the reinforcing mesh is embedded, then the Oberputz is applied in one or more layers to achieve the desired texture. Proper curing, weather protection, and joint control are important to prevent cracking and delamination.

Maintenance involves cleaning, inspecting for cracks, and patching with compatible plaster, with repainting or refinishing as needed. Putzaufbau should comply with local building codes and standards, with attention to substrate compatibility, vapor permeability, and thermal performance.