What is a significant disadvantage of synthetic grout?

The significant disadvantage of synthetic grout is its usable time, typically ranging from 30 minutes to 1 hour after mixing. This limited working time can pose challenges in various applications, particularly when larger areas or more complex installations are involved. It requires careful planning and swift execution to ensure that the grout is applied effectively before it begins to set.

The other aspects listed do not indicate a significant disadvantage. Synthetic grouts may have varying shelf lives, but a typical lifespan of 3 years is reasonable for many construction materials. They can also be applied in lower temperatures, making them versatile in colder climates. While issues such as moisture, chemicals, corrosion, and vibrations can affect many materials, properly formulated synthetic grouts are designed to withstand these factors to some extent, depending on their specific formulation and intended application. Hence, the limited usable time is the most critical drawback for practical use.