Using 2x4s as sheathing for exterior walls is not a common practice and may not be the most suitable option for several reasons:
Structural integrity: Plywood or oriented strand board (OSB) sheathing provides structural stability to the building envelope. They are specifically designed to distribute loads and resist forces such as wind and seismic activity. 2x4s alone may not provide the same level of strength and stability as engineered sheathing materials.
Moisture and insulation: Plywood or OSB sheathing acts as a moisture barrier and helps to prevent water intrusion into the wall assembly. Additionally, sheathing can provide a layer of insulation, improving the energy efficiency of the home. 2x4s do not offer the same protective qualities against moisture and may not provide any significant insulation benefits.
Building code compliance: Building codes often specify the use of specific materials for sheathing to ensure structural integrity and compliance with safety regulations. Using unconventional materials like 2x4s may not meet these requirements and could potentially lead to issues during inspections or impact the overall durability and safety of the structure.
Cost-effectiveness: While using 2x4s as sheathing may appear cost-effective in terms of initial material costs, it's important to consider long-term maintenance and potential risks. Plywood or OSB sheathing is a tried and tested material with proven performance, which can save costs in the long run by avoiding potential issues or the need for repairs.
It's always recommended to consult with a professional architect, engineer, or contractor who can assess your specific project requirements and provide guidance on the appropriate materials and construction methods for your exterior walls. They will consider factors such as local building codes, climate conditions, and structural needs to ensure a safe and durable construction.