Real scratch plaster offers various advantageous properties such as dispersion openness and a particularly good ability to store heat. Painting scratched plaster surfaces with commercially available wall paint is actually not common, as it affects the physical properties of the plaster surface. Therefore, you should weigh very carefully whether you really want to paint a scratch plaster.
Why is scratch plaster actually not painted??
The real scratch plaster is a means of wall design that actually does not cause any major renovation work for decades. Scratch plaster is traditionally used especially on the outer wall, for example to prevent the formation of fine cracks. After all, it is a sandy plaster that is not characterized by a smooth, but rather by a particularly irregular surface structure. The sandy surface of scratch plaster allows individual grains of sand to "trickle down" over the years. For this reason, a facade made of scratched plaster is usually also referred to as "self-cleaning". In addition, scratch plaster also offers the following properties:
- it is open to dispersion and compensates for fluctuations in humidity
- acts like a heat store
- can simply be "rubbed clean" in the affected area if it is dirty
If a surface made of scratch plaster is painted with commercially available wall paint, its surface is sealed and it loses these special properties.
What alternatives to painting are possible??
As a rule, scratch-plaster facades or interior walls should be painted if they look dirty or faded. In such a case, a scratch plaster that is initially applied thickly enough does not have to be painted, but simply rubbed off with a suitable tool such as a nail board. As a result of the circular rubbing, a thin layer of scratch plaster is rubbed off, so that, as a rule, an absolutely flawless and uniformly colored surface should appear again. If the scratch plaster was applied in the prescribed thickness during processing, this special renovation measure can sometimes be carried out several times (over the course of decades). In order to prevent soiling in the areas not reached by the rain, you can wash your external scratch plaster about every two years with the garden hose. In this way, some grains come off evenly along with the accumulated dirt.
If your wish to paint scratch plaster is related to the longing for a different wall color, a further layer of scratch plaster can theoretically be applied to the existing plaster.
How should you proceed when painting scratch plaster?
If a surface made of scratched plaster is actually to be painted, you must first remove loose dust from the wall with a water hose or a brush or broom. If the wall is completely dry again, an adhesive primer (€ 19.50 at Amazon *) must first be applied. So that the paint can then really get into every small depression on the wall surface, a paint should be used that can be diluted with water, for example.