What is the primary purpose of a collar tie in roof framing?

A collar tie is a horizontal member that connects two opposing rafters in a roof framing system and is typically installed near the ridge. Its primary purpose is to prevent the rafters from spreading apart due to the weight of the roof and any external forces, such as wind. By keeping the rafters in place, collar ties contribute to the overall structural integrity of the roof system, ensuring that it remains stable and can support loads appropriately.

While supporting the roof load is vital, that role falls mainly to the rafters and other structural components like beams, rather than the collar ties themselves. Enhancing insulation and improving aesthetic appearance are secondary functions that might be influenced by other elements of roof design and construction, but they are not the primary responsibilities of a collar tie. Its main focus centers on maintaining the alignment and structural stability of the rafters in a roof framing system.