Effect of Atmospheric Conditions on Plaster
The prevailing weather at the time of plastering or during the setting, drying and hardening period may affect the finished work as follows:
1. Frost
The destructive effect of frost on plaster work is significant. Unless special precautions are adopted, plastering work shall be suspended entirely during frosty weather.
2. Cold
The setting and hardening times of all plasters are appreciably lengthened by a reduction in the atmospheric temperature. Where plastering has got to be carried out in cold weather, the time intervals should be lengthened to allow for this, and the work programmed or re-programmed accordingly.
3. Condensation
In certain localities condensation resulting from cold wintry conditions may be so excessive as to impair the finished plaster work. It may also retard or prevent the drying out of wet building operations for periods of week, or even months, thus presenting conditions unsuitable for plastering.
4. Extreme dry conditions
Under hot dry conditions the applied plaster may become dry before the setting process is sufficiently advanced. The partially set weak material often has a powdery surface which will not provide a satisfactory base for the subsequent coat or for decoration. Plasters containing cement are particularly sensitive in this respect. In such contingencies the surface should be continually kept wet during the curing period.