Cement plaster coats shall be protected from freezing for a period of not less than how long after set has occurred?

Cement plaster requires proper curing conditions to ensure that it achieves the desired strength and durability. Protecting it from freezing is critical because if the temperature drops too low shortly after the plaster has set, it can lead to inadequate hydration processes, which may compromise the integrity of the plaster.

The established guideline of maintaining protection for a minimum of 24 hours after setting is based on the time it typically takes for the plaster to gain an initial strength sufficient to withstand minor thermal stresses. This timeframe allows the chemical reactions within the cement to progress to a level where the material can tolerate cooler temperatures without experiencing damage.

Moreover, during this initial curing period, moisture is vital for proper curing. If freezing conditions occur during this time, the expansion of freezing water within the plaster can cause cracking and loss of adhesion, leading to long-term structural issues. Thus, ensuring a full day of protection from freezing significantly helps in maintaining the quality and longevity of the plaster application. Proper awareness of these curing and protection timelines is essential for contractors when working with cement-based materials.