What are rafters traditionally used for in roof structures?

Rafters play a crucial role in the construction of roof structures by serving as inclined structural members that support the sheathing. They are typically arranged in pairs to form the framework of a roof, extending from the ridge or peak down to the eaves or the walls below. This alignment allows rafters to handle the load from the roof covering and any additional weight such as snow or wind pressure effectively.

By providing a framework that supports the sheathing, rafters contribute to the overall integrity and stability of the roof. The sheathing, which is often made of plywood or oriented strand board, is then fastened to the rafters, creating a solid base for the final roofing material (such as shingles). This relationship is essential for preventing roof sagging and ensuring that the roof can withstand various environmental factors.

While rafters do contribute to the roof structure, they do not serve as connecting members in the way that some other parts of the roof system might. They also do not directly support insulation and ceiling materials or provide a foundation for trusses, which serve a different structural purpose altogether. Understanding the specific function of rafters within the roof system is key to appreciating their importance in building design and construction.