How can I remove blooming from bricks

Efflorescence on clinker - what to do?

Determine the cause

Basically, you should always look for the cause of the efflorescence first. In the case of clinker facades, this is usually too much moisture penetration into the masonry during the construction phase.

The salts that are visible as efflorescence rarely come from the brick itself, but mostly from the mortar (7.79 € on Amazon *).

In the case of stones in contact with the earth (or stones that have been stored unprotected on the ground), the salts can also come from the stone. Even if the facade was cleaned with a lot of hydrochloric acid after completion (6.95 € on Amazon *), efflorescence can occur later.


So-called leaching, white tracks from the brickwork, usually arise when the mortar used was faulty or not processed properly. Leaching is mostly about easily soluble components of the mortar, usually CaOH2 (calcium hydroxide).

Pavement and stones in contact with the earth

With all clinker bricks that come into contact with the ground, efflorescence can usually not be avoided. The cause here is either salty water from the ground or (very often and with massive effects) road salt.

Eliminate efflorescence

Basically, efflorescence on the clinker facade is washed off by the weather and disappears completely within 1 - 2 years. The reason for this is that after this time a so-called "equilibrium moisture content" has set in on the building, which prevents further efflorescence.

If this is not the case, or if the weather does not remove the traces, you can simply remove any efflorescence using a dry brush (brush, scrubber). In severe cases you can also use (little!) Water or warm water in the case of poorly soluble salts.

From a structural point of view, efflorescence is in any case a defect for which improvement can be requested from the company carrying out the work. However, the Federal Ministry for Spatial Planning regards efflorescence as a “deficiency that can be tolerated to a certain extent”, especially in clinker facades. That must then be assessed on a case-by-case basis.

Author: Johanna Bauer

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