Lime plaster a mold killer?

Lime is a proven mold killer - and to a certain extent that applies to lime plaster as well. However, this also depends on the conditions in the building on the one hand, and on how much the lime plaster or the lime paint has been carbonated through on the other hand. There is also some effective advice for old lime and damp walls, where lime was the only clean and smooth paint available.


Air-lime plaster is something very simple - namely a mixture of white lime hydrate and fine, sharp-edged sand. You can usually easily make it yourself, the mixing ratio, usually around the 3: 1 (3 parts sand, 1 part lime) can be recognized without any problems in the consistency of the plaster, which thus arises. Basically, namely:

The fewer additives to the lime scale, the better the anti-mold effect.

Some finished products contain mortar additives, which in turn can be a good breeding ground for mold. The mildewing effect of lime is then no longer sufficient here. The more additives are dispensed with, the lower the risk of mold.

Structural conditions and other circumstances can cause mold formation despite limescale. The biggest overall risks for mold growth include:

  • high humidity
  • bad ventilation
  • poor structural seal and insulation
  • Temperature fluctuations around the dew point, which can lead to condensation of water vapor

Combined hygrometers, which can also display and record temperature and humidity fluctuations, are worthwhile here to find the cause. You get them relatively cheap in stores, even in some online stores. If risks are identified, lime alone is often not enough to prevent mold growth. The problem must first be tackled at the root.

Lime inhibits only the growth of mold, lime plaster can not always prevent the formation of mold by itself

The main effect of lime is on the one hand based on its breathability (the wall can breathe), on the other hand also in its chemical properties, which makes lime a very poor breeding ground for mold. In addition, the lime plaster itself can absorb a large amount of moisture from the air and thus - similar to clay - regulate the humidity a bit. The emphasis here is on "something". Wet rooms remain wet rooms, despite lime plaster.

Remove mold on lime plaster: this is how it works.

If mild mold has formed on the lime plaster, first fix the cause, then remove the mold with 70% alcohol and paint one or two layers of lime over the wall. This should then fix the problem. Adding one or two packs of quark per bucket to the marsh limestone can be even better as an old home recipe.

Video Board: Mold or mildew in your home