ETICS Reinforcement - Instructions

A thermal insulation composite system is now installed in many new buildings and existing buildings. Decisive on the insulation is the reinforcement, which also forms the plaster base. Below you will find instructions on how to apply the ETICS armor.

Construction of a thermal insulation composite system

Many buildings are nowadays packaged for thermal insulation, so to speak, with thermal insulation panels. The structure is always very similar:

  • Girder (existing facade)
  • Thermal insulation panels (for example made of rockwool or EPS)
  • Fixing the insulation boards by gluing and / or dowelling
  • Reinforcing layer and plaster base
  • Monomass

First of all, it is very important that you coordinate the products you use exactly. Even the method of attachment (dowels, gluing or both methods in combination) depends on the chosen system.

Tasks of the ETICS reinforcement

The ETICS reinforcement has several tasks. Plaster layers and insulation boards absorb heat equally, but cool down significantly differently. This results in completely different thermal movements within the same time window. The reinforcement neutralises these stresses by the reinforcing layer absorbs these and distributed over a large area.

The reinforcement consists of a special reinforcing mortar and a reinforcing mesh. Most EPS insulation boards are used. For this very special reinforcing mortars are used again. These are chemically treated in such a way that they easily dissolve the surface of the EPS sheets and virtually connect with them - similar to water glass. This ensures a secure connection.

The reinforcement as a plaster base

At the same time, the reinforcing mortar also serves as a primer. The substrate for the actual top coat is thus equalized on the one hand, so adapted to the necessary properties for the subsequent plaster and serves on the other hand at the same time as a primer and primer. These ETICS reinforcements including the used topcoats are optimally coordinated systems. These must therefore also have a demanding authorization within the EU.

Concrete construction of reinforcing mortar and reinforcing mesh

Thus, a reinforcement fabric is usually inserted in the upper third of the layer thickness of the reinforcement. This is made of fiberglass and must be alkali resistant. After all, top plasters are structured to prevent long-term algae, moss or lichen growth. Also, the layer thickness of the reinforcement itself varies usually between 1.5 and 5.0 mm.

The filling of the reinforcement fabric

Another special feature is the required properties of the reinforcement, which lead to a corresponding processing. Reinforcing mortars require a high tensile strength, but only a low compressive strength. When it comes to cleaning, it's the other way around. Therefore, reinforcement mortars should also not be used as top coat, they are mechanically simply too soft among other unsuitable properties.

The reinforcement fabric must be incorporated in a high density mortar. Therefore, relatively light plasters such as light plasters are also not suitable, since the subsequent plaster density is too loose. In addition, one speaks for this reason not from conventional plastering, but by filling, as this also implies the higher mortar density to be achieved.

Instructions for ETICS armouring

If a mortar thickness of 5 mm is required (the thickness is specified by the manufacturer!), Apply about 3.5 mm of reinforcement, then the reinforcement fabric is inserted. At the edges, the reinforcement fabric should overlap by 10 cm. Also note the special features on corners and edges with appropriate reinforcing corners.

Then a layer in about one third of the thickness of the lower layer, ie again about 1.5 mm in this case, is troweled. This step is done wet in wet. The procedure varies from one fitter to another - some prefer a dental arch, others a smooth trowel. Then the drying times for the reinforcing mortar must be taken into account before you apply the appropriate finishing coat.

Tips & Tricks

You can read all about the strength of the reinforcement when using different reinforcement mortars and plaster systems here.

Video Board: How to apply the base coat and reinforcing mesh - Installation of thermal insulation / EIFS