6. Concrete cleaning

A number of precautions must be taken before defining the cleaning technique. A thorough examination of the substrate is required, along with information on :

• the nature of the concrete to be treated: nature of the binder and aggregates ;

• surface and protective treatment (type of paint) and, if necessary, application of a water repellent;

• the nature of the joints.

Examination of the facing should detect any signs of oxidation of the reinforcement (rust stains, adhesion of the concrete covering).

Critical points are always fascias, balconies, lintels, acroteria, shutter seals, railings, etc.).

In most cases, conventional cleaning methods are used to remove dirt from concrete facings. But if,...