Remove efflorescence - you must pay attention

Efflorescence on a wall is very annoying and visually very ugly. How to remove them (permanently) and what you should always consider when removing, read in this post.

Recognize causes

The principal cause of efflorescence is always moisture. Moist cellar walls show visible deposits when moisture evaporates. Then efflorescence occurs on the plaster or wall surface.

Another possibility is the presence of ammonia (for example due to former faecal contamination of the wall or from the room air). In this case, nitrates crystallize out and form the typical efflorescence, which is then called "wall saltpeter". Wall saltpetre is more dangerous, since crystallization of calcium nitrate from the wall may under certain circumstances seriously impair wall stability.

elimination methods


A permanent elimination of the efflorescence succeeds only if the wall is actually completely dried out and effectively and permanently protected against penetrating moisture.

As soon as moisture reaches the wall, efflorescence will be possible again and again because the diffusing water will carry the salts it contains.


If permanent drying can not be guaranteed, only "desalting" the wall will help. This can be done by different methods:

  • Technical washing out of the salts from the walls
  • Compression technology (special compresses from bentonite and sand, above air lime mortar
  • victims plasters

The existing plaster, which usually also represents a salt storage, must also be knocked off for this. For the new plaster then building materials must be used without harmful salts.

Mechanical removal

Already existing efflorescence are only salt residues. They can be easily removed with a spatula or a brush from the wall.

Tips & Tricks

Never take damp basement walls lightly, or damp on other walls where you will notice efflorescence. Incoming water can severely damage the building fabric in the long term.

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