In this how it works article managing editor debra judge silber explains the role of collar and rafter ties in the framing of a roof.
Roof rafter collar ties.
By upper third here we mean one third of the length of the rafter from ridge to top plate.
The collar ties are used to strengthen the roof rafters to prevent them from buckling or sagging under the weight of the roof.
A tension tie in the upper third of opposing gable rafters that is intended to resist rafter separation from the ridge because of wind or unbalanced roof loads.
Collar ties attach between every other pair of opposing rafters at.
A collar tie is a horizontal roof rafter compression connector that is located in the uppermost third of the span of a pair of opposed sloped or gable roof rafters.
A collar tie is a tension tie in the upper third of opposing gable rafters that is intended to resist rafter separation from the ridge beam during periods of unbalanced loads such as that caused by wind uplift or unbalanced roof loads from snow.
Collar ties provide additional structural support for wood framed roofs that bear the weight of clay or concrete roofing tiles.
Collar tie is a colloquial term for collar beam.
Collar ties may take up space in the attic of your home but they are there for a reason.