PROBLEM

The degradation mechanism due to salt efflorescence is a consequence of the crystallization pressure of some salts, which have the characteristic of considerably increasing their volume during the passage to the solid phase, following the evaporation of water; the pressures caused inside the pores are such as to overcome the resistance capacity of the material and the result is the continuous erosion and disintegration of the surface layers of the materials. Several saline compounds can be found, in the form of aqueous solution, inside the walls. Their deposition on the surfaces depends both on the degree of solubility of each compound, and on the greater or smaller quantity of water necessary to solubilize them.

The salts can come from: the ground (especially the Nitrates and the Chlorides); from the deposition of aerosols present in the atmosphere (Chlorides and Sulfates); from the same material used for construction (alkali metal sulfates may be present in bricks, calcium and magnesium sulphates may be present in limestone, etc.); from localized infiltrations.

The growth of crystals of inorganic salts (nitrates, sulphates, sodium chloride, etc.) within the pores of a stone causes fragmentation and in extreme cases, pulverization.

The resistance of porous materials, to the damage caused by salts, depends on the distribution of the size of the pores inside them; it, all other conditions being equal, decreases as the concentration of pores with small dimensions increases.

SOLUTION
The resolutive and conservative intervention of the problem involves the complete removal of the efflorescences present on the surface and, if possible, the extraction of the salts inside the same materials. Furthermore, it is essential to solve the causes that produce the crystallization of salts with targeted and definitive interventions.

In case the problem of salts is mainly caused by the interaction between material and outdoor environment, after the cleaning operations it is necessary to hydrophobize the surfaces concerned in order to keep the salts in solution inside the materials, thus avoiding their crystallization outdoors, so if you are in a situation of thermodynamic stability the damage found will be insignificant.

The products used for the treatment against superficial salt efflorescence must be able to:

  • Act on a broad spectrum to eliminate the various types of salt crystals that can be found on materials
  • Do not alter the porosity of the supports
  • Do not deposit harmful reaction products on materials

Application

ANTISALI A

brush spray roller

PULI AC

brush spray roller

INTERVENTION CYCLE

  • Dry-brushing of surfaces affected by efflorescence
  • If it is considered necessary the extraction of the salts with TAMPONE ANTISALE
  • Complete the salts removal with the specific cleaner PULI AC
  • Apply the specific protective ANTISALI A on a clean and dry surface
ADVANTAGES OF CIR SOLUTION
The solution proposed by CIR allows to act on all types of salts that can be found on building materials, in a selective way, without causing damage or abrasion on materials.

It also allows to intervene on several levels of deterioration and on various types of material or facade.

The SOLUTION proposed by CIR have the following advantages:

  • IT IS NOT SUBJECT TO QUICK AGING
  • IT HAS A GOOD RESISTANCE TO CLIMATE CONDITIONS
  • IT DOES NOT INTERFERE ON THE THERMODYNAMIC PROPERTIES OF THE MATERIALS
  • IT IS RESPECTFUL OF THE MATERIALS
  • IT ACTS ON A WIDE SPECTRUM IN MULTIPLE CASES
THE TECHNICIAN RECOMMENDS
In order to carry out a resolutive intervention of the problem it is necessary to analyze and solve at the base the causes that lead the salts to come out.

Contact us for advice or free inspection: ufficiotecnico@circhimica.it