Exterior plaster can withstand frost when applied properly

Of course, an external plaster is protected according to its task against frost and resistant. Prerequisite for this property is a perfect processing and proper bonding. If the outside and component temperatures are too low, plastering should be postponed. The same applies to other extreme weather conditions.

Functions of exterior plaster

Although the external plaster on the house is often one of the last completion features of the house, in winter is advised against the execution. Every plaster has several tasks:

  • He visually disguises the building
  • It protects the masonry from precipitation
  • He lets the masonry in most cases "breathe"
  • It can fulfill insulation function as in thermal protection
  • It can be the basic component and carrier of a thermal insulation composite system
  • It ensures regulated surface wetness and prevents "blasting" due to ice formation

Too early frost destroys frost resistance

The exterior render can only fulfill all functions permanently and reliably if it is properly treated in its "child-time". Application of external plaster should never be performed below five degrees Celsius component and air temperature. If the exterior finish freezes before it sets, it loses its frost resistance for the future as well. This happens even if there are no immediate damages such as cracks.

Some craftsmen and manufacturers assert that their products and processing are also possible in borderline areas up to zero degrees Celsius. Occasionally, antifreeze surcharges are offered as a solution. However, this is more like masking symptoms and is less about avoiding causes.

How much degree of external plaster is applied, processed and dried is the decisive factor for the physical reliability of the building skin. This applies to too low and too high temperatures. When setting process, the plaster "sets" by water loss. The evaporation must not be slowed or accelerated. Only with "healthy" setting periods of about one day per millimeter layer thickness does the outdoor plaster develop weather resistance against frost and precipitation.

Tips & Tricks

Even if it can be a tough decision and has a strong influence on a home's construction and reference plan, you should only apply your outdoor plaster, which is to last for decades, in times that are certainly frost-free.

Product Image: Metehan Girisgen / Shutterstock

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