Re-plaster a wall

The plastering is more and more often done by home improvement. Below is an overview and instructions on how to plaster an interior wall again.

The different plaster types also for the inner wall

Before you start plastering, the different types of plaster should be known inside and out. Since you want to plaster a wall indoors, in particular basic knowledge of the types of interior wall plaster are important. In principle, the following plasters are distinguished:

  • Lime plasters (outside and inside)
  • Gypsum plaster (inside)
  • Cement plasters (mainly outside)
  • mineral plasters such as clay plaster (inside)
  • organic plasters such as synthetic resin plaster (inside and outside)

The different binders can also be combined with each other.

Preparing the wall for plastering

Old plaster must be completely removed under certain conditions. For example, when it sandes or dissolves in large areas. If the old plaster is load-bearing, unevenness must first be compensated, as in the case of a rough wall. Most plasters can not be used to fill niches and spaces, as they would simply fall out. They do not have the required properties.

Instead, renovation mortar or leveling compounds are used here. Instructions for filling walls can be found here. Even large bumps are corrected to some extent before plastering.

In mixed masonry as well as in old plaster and in general, a uniform adhesion of the plaster must be guaranteed. If a wall is highly absorbent, it removes too much water from the plaster. On the other hand, a barely or non-absorbent wall does not provide sufficient adhesion for the new plaster. Therefore, the wall must be prepared with a primer. Adhesive primer for walls with little or no absorption, deep foundation for strongly absorbent masonry.

Repopulate crooked walls

Superficially, plastering is about making a smooth and even wall. Therefore, the new plastering, especially in old buildings, the opportunities to straighten oblique walls. This requires "lessons". These are usually metal profiles that are assembled at regular intervals. In between is filled with plaster and removed with a Abziehlatte using the profile gauges.

Additionally required: edge protection, reinforcements

On corners, an edge protection must be applied when plastering. These profiles can be purchased in the building materials trade. Depending on the strength and consistency of a plaster also a reinforcement must be inserted. Differences are made between the reinforcement and reinforcement. Reinforcements in the upper third of the plaster should evenly distribute applied mechanical stresses (for example due to stresses).

Reinforcements, on the other hand, are incorporated in the lower third of the plaster and are mainly used in priming as a reliable plaster base. Reinforcements today mainly glass fiber mats are used. Many of these mats are not alkali resistant, but this is important because, for example, lime plasters are highly alkaline. Here you can read about how to apply reinforcing mesh on interior plaster.

Depending on the plaster, it is applied in one or more layers. For this, it is essential to observe the manufacturer's instructions. This also applies to the drying times between two work steps. Conventionally, there is a plastered wall, including a newly plastered wall, a primer (plaster base) and a surface and / or decorative plaster. Decorative plasters are applied only very thinly.

Note further requirements when repainting the wall

Especially in old buildings can be added to other requirements. So wet or damp walls are a big issue in existing buildings. If you use a highly vapor-permeable plaster, it may be possible to evaporate too much water in a previously damp wall so quickly that the capillary effect, which pulls the water upwards into the wall, is broken.

Tips & Tricks

You can also mix plasters with color pigments if you want a colored plaster on your wall. If you are already planning further coatings on the newly plastered wall, you should consider this already during the plastering choice. Thus, the glazing of walls should be done primarily on lime plaster and not gypsum plaster.

Artikelbild: SimoneN / Shutterstock

Video Board: How to plaster a wall, a beginners guide. Plastering made easy for the DIY enthusiast.