Roof rafters are inclined structural members that extend from the roof ridge down to the exterior walls of a building. They form the primary skeletal framework of sloped roofing systems and are typically made from dimensional lumber or engineered wood products. The main function of rafters is to support the roof load, including decking, insulation, roofing materials, and environmental loads such as snow and wind. Rafters transfer these loads down to the walls and ultimately to the foundation of the structure. In traditional stick-framed roofs, rafters are cut and installed individually on-site, while modern construction often uses prefabricated trusses that serve a similar structural purpose. Rafters must be precisely spaced and aligned to ensure even load distribution and prevent structural weaknesses. They also play a role in determining roof pitch and attic space configuration. Proper bracing and connection at the ridge and wall plates are essential for stability. Any failure in rafter integrity, such as rot, cracking, or insect damage, can compromise the entire roofing system and requires immediate structural repair.
