Apply in cold and wet weather

Apply in cold and wet weather

Weather conditions can decisively affect mortar-setting and, therefore, the final characteristics of the coating.

Therefore, the presence of very cold temperatures or high degree of humidity can give rise to:

  • A decrease in the final resistance of the mortars.
  • The appearance of carbonations (white stains) or salts on the coating surface.

Preliminary analysis

It is of vital importance to supervise certain aspects, prior to the application of a coating mortar, as it may be affected by the current weather conditions.


  • Substrate temperature:

In the event of very low temperatures, the adherence of the fresh mortar may be compromised, due to the possible freezing of the paste when it comes into contact with the substrate and, consequently, a lack of adherence thereto.


  • Ambient temperature:

Likewise, low ambient temperatures affect the mortar setting process and can cause the appearance of carbonations.

If the temperatures fall to below freezing point, the mortar hydration process would be interrupted, considerably decreasing the final resistance of the coating.

For this reason, it is obligatory to avoid applying a coating if frost or low temperatures in the hours following its application is obligatory.


  • Humidity:

The possible presence of rain or humidity, both during setting and in the hours following application of the mortar can also give rise to the appearance of carbonations.

Therefore, it is important to protect the façade from direct exposure to water by installing a gutter and, if necessary, protect it from rainwater when the coating mortar is hardening.

Technical considerations

  • The use of a setting accelerator (GECOL Acelerante) is essential, since in cold environments it reduces the setting and solidification wait times of mineral cladding or one-coat mortars, thereby reducing the problems that arise during setting of these products.

Likewise, productivity is significantly increased, as the desired finishes or textures can be executed in the same day: scraping, floating, smooth, stippling, etc.

It must be considered that GECOL Acelerante is not an antifreeze additive and therefore the application temperatures, comprised between +5ºC and +35ºC (measured on the substrate), must be observed and the coating must not be applied to a frozen or semi-frozen substrate or with risk of frost in 24 hours.

The application limits of the mixture with GECOL Acelerantw are the same as those of any coating mortar.

  • For the removal of white stains or salts, as a result of the carbonation of the product, we must proceed as follows:
      • Prepare a diluted solution with water in the ratio 1:6 of GECOL Desincrustante.
      • Wash the substrate with said acidulated solution.
      • Rinse with clean water.
      • Wash the substrate again with said solution.
      • Rinse again with clean water.

Finally, the other option to solve the aesthetic aspect of the stains, would be to apply later to acid cleaning, the special paint for external coatings GECOL Cril (diluting it in water up to a maximum of 30% and trying in the application not to influence in the texture of the support)

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Warnings: The data provided by this Constructive Solution were prepared based on standard onsite installation processes. However, we recommend that you consult our Technical Department in the event of any specific circumstance