Exterior plaster frozen too early

Properly processed and applied exterior plaster will be frost resistant. However, if the plaster is frozen too early, its setting will be disturbed and damage will occur. In addition to the air temperature, the substrate or masonry must not be too cold. Another risk of damage is excessive water absorption of the plaster.

Putzarten are sensitive differently

In particular, mineral plasters are popular because of their sufficiency and long life. They can be processed within limits even in cold temperatures. Resin plasters and silicate plasters are much more sensitive to temperatures that are too low.

For all plasters, frost should be avoided during the setting phase. The lowest possible processing temperature of five degrees Celsius should not be undercut. Special anti-freeze additives can make the exterior plaster on the house less sensitive. But they are designed for the correctly set plaster.

Assessment and processing criteria

In winter periods, which border on the minimum temperatures at which the external plaster can be processed, several factors must be considered:

  • The masonry temperature should not fall below four degrees Celsius at night
  • The air temperature should not fall below zero even at night
  • The setting time for concealed installation is one day per millimeter of material thickness
  • The top coat needs depending on the composition between four to ten days
  • The exterior plaster is very sensitive to complete setting and drying out
  • Within the setting phase, the fresh plaster should be protected from rain
  • Reinforcement and fabric applied in the plaster extend the setting phase by at least one week
  • The most time specified by the manufacturer corresponds approximately to the setting time

Physical aspects

When doing your own plastering outside, the physical aspects should be considered:

  • The exterior plaster covers a facade or wall like a skin and "clings" to the ground
  • If the connection to the ground has defects, the plaster does not hold. In frost he is on his own.
  • When the exterior plaster draws moisture, frozen water entrapments create small "detonators" of ice
  • The outer plaster behaves differently when expanding and contracting due to temperature fluctuations than its support materials

Tips & Tricks

If you add anti-freeze when making your own external plaster, you risk subsequent efflorescence for possible processing in winter temperatures.

Artikelbild: Radovan1 / Shutterstock

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