In a roof structure, where should collar ties or ridge straps be installed?

The installation of collar ties or ridge straps is critical for maintaining the structural integrity of a roof system. These components are designed to provide horizontal support and prevent the roof from sagging or experiencing structural failure under load.

When rafters are spaced on 24-inch centers, the recommendation to install collar ties on every other rafter ensures that there is sufficient support distributed throughout the roof structure. This arrangement allows for an effective transfer of loads and helps to stabilize the roof in high wind conditions or when heavy snow accumulates. By placing collar ties on every other rafter, it strikes a balance between adequate support and practical construction methods.

This strategy prevents excessive weight on any single rafter while maintaining the overall strength and rigidity of the roof. Additionally, using collar ties in this manner helps mitigate diagonal tension loads that could lead to roof buckling or failure. As a result, this approach aligns with structural engineering best practices for roof designs, making it the most suitable choice.