What key factor is considered in plain masonry?

In the context of plain masonry, tensile resistance is a critical factor because masonry inherently has a lower tensile strength compared to its compressive strength. Understanding this property is essential when designing masonry structures, as it can influence how load forces are distributed and how the materials will perform under stress. Plain masonry may not be reinforced, which makes it particularly important to account for how tensile forces are handled to prevent cracking or failure.

The other factors, while still important in a broader sense, do not directly pertain to the core attributes of plain masonry itself. For instance, thermal expansion is relevant to materials that may experience significant temperature fluctuations, but in the scope of plain masonry, it's the ability to withstand pulling forces without reinforcement that takes precedence. Aesthetic appeal, while important in design decisions, does not affect the structural integrity of the masonry. Similarly, moisture control is essential for the long-term durability of masonry structures but does not specifically relate to the mechanical properties that tensile resistance addresses.