What is the purpose of sheathing in wall construction?

Sheathing in wall construction serves multiple critical functions that contribute to the overall performance and durability of a building.

First, it plays a vital role in adding structural strength to the walls. Sheathing materials, such as plywood or oriented strand board (OSB), provide rigidity and help the walls resist lateral forces, such as wind and seismic activity. This structural support is essential for maintaining the integrity of the building over time.

Second, sheathing serves as a barrier to moisture. It helps to protect the interior of the wall assembly from water infiltration, which can lead to mold growth, wood rot, and other moisture-related issues. Properly installed sheathing contributes to the overall durability of the exterior wall system, safeguarding the building's interior components.

Lastly, while insulation is not the primary role of sheathing, it can contribute to the thermal envelope of the building. Some sheathing products are designed to include insulation properties, further enhancing energy efficiency.

Given these multifaceted roles, the purpose of sheathing is comprehensive, encompassing insulation, moisture protection, and structural strength, which is why the conclusion is that all of the mentioned functions are critical aspects of sheathing in wall construction.