How it Works: Collar and Rafter Ties
Collar ties may take up space in the attic of your home, but they are there for a reason. In this “How It Works” article, managing editor Debra Judge Silber explains the role of collar and rafter ties. Collar ties are necessary to prevent separation of the roof at the ridge due to wind uplift. Rafter ties resist the forces caused by gravity loads that would otherwise cause the roof to pancake and push out the sidewalls. Rafter ties are required by code, unless the house is designed so that the walls or a structural ridge beam carries the full load of the roof. This article includes a technical illustration about collar and rafter ties.