Exterior plaster must have a higher thickness in the ETICS

In a thermal insulation composite system (ETICS), the plaster layers are combined with an insulating material. The basic layer, which is otherwise referred to as a concealed surface, becomes the reinforcing layer in technical usage. To achieve the desired insulation effect, a thickness of the external plaster is required, which differs from other plasters.

Three layers form the outer plaster

The combination of an insulating layer and an external plaster is called ETICS. Unlike the simple application of external plaster on polystyrene or applied without insulation layer thermal protection, the thickness must be matched to the total insulating effect. This does not necessarily lead to higher structural strengths.

The structure principle of a ETICS consists of three layers:

1. Insulating material such as Styrofoam, Styrodur, mineral wool, fiberboard
2nd Armierungsschicht, otherwise referred to as flush with Gewebespachtelung
3rd surface plaster

The reinforcing layer assumes the indispensable function of decoupling the different material properties of insulating material and plaster.

The central reinforcing layer

By choosing the right thickness of the reinforcing layer, the durability of the plaster and the insulating effect stand and fall. While the laying of concealed plaster can also be partially reinforced in a conventional manner, complete reinforcement is required for ETICS.

Depending on the ETICS, the thickness of this layer varies between 1.5 and 15 millimeters. The layer, which is also referred to as concealed, must absorb the reinforcement fabric, usually made of fiberglass, "full". As plaster types, mineral plasters and plaster provided with synthetic resin come into question. They have to fit the later finishing coat.

The plaster in the ETICS has a total thickness between 9.5 and 35 millimeters

In order to influence the overall thickness and thickness of the exterior plaster, different top plasters are available. The thickest fall
mineral plasters such as lime cement plaster. The so-called thick-layer plasters produce eight to twenty millimeter thick layers depending on the grain thickness.

The following plasters can be used for thinner surface finishes in ETICS:

  • Synthetic resin plaster
  • silicate plaster

The decision as to whether a silicate render or a silicate resin render is used depends on the reinforcing layer. Basically, "Gleich und Gleich likes to join." The top coat must be softer than the flush:

  • Upper plasters with resin content only on resin-containing sub-plasters or reinforcing layers
  • Mineral topcoats only on mineral sub-plasters or reinforcing layers

Tips & Tricks

Applying only thermal insulation with no additional insulation layer can achieve up to thirty percent of the insulation efficiency with about half the total thickness.

Artikelbild: Bilanol / Shutterstock

Video Board: Application and installation of an external wall insulation system