What is the primary cause for a masonry wall to collapse while under construction?

A masonry wall's primary cause of collapse during construction is often due to a lack of proper bracing combined with adverse changes in wind conditions. When walls are being built, they are typically not self-supporting until fully constructed and cured. Wind can exert significant lateral forces on unfinished walls, especially if they are tall or if the wind speed increases suddenly. Without adequate bracing to stabilize the wall during this crucial phase, the forces can lead to tipping or structural failure.

Bracing techniques are essential to ensure stability, especially in adverse weather conditions. This combination of factors makes it a critical aspect for contractors to manage during construction. While improper mortar mixing, excessive weight, and inadequate foundation support can also contribute to structural issues, they are typically more relevant in the context of completed structures or later phases of construction rather than during the construction phase itself.