Collar ties rafter ties tension beams structural ridge beams.
Attic trusses and rafter ties.
Firstly the tributory width d should be 3d as only every third rafter is tied.
Toenailing is one of the more straightforward methods of attaching rafters or trusses to the top plate while hurricane ties offer superior strength to ensure your roof stays where it belongs.
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 collar ties are necessary to prevent separation of the roof at the ridge due to wind uplift.
In many situations you ll find that ceiling joists installed parallel to the rafters are intended to function as rafter ties.
The roof framing mock up below shows a standard rafter tie.
Since l is the half width of the roof the load should be w not w 2 and there are other serious things wrong with this.
Also the un tied rafters push on the wall plates which span between the tied rafter ends bringing in 2 3 of the load on the tie and adding to the bending in the tied rafters.
A rafter tie is a tension tie in the lower third of opposing gable rafters that is intended to resist the outward thrust of the rafter under a load.
Collar ties may take up space in the attic of your home but they are there for a reason.
This article describes and illustrates the different types of support that prevents roof sagging and wall bulging at buildings including definitions of collar ties rafter ties and structural ridge beams.