Shed Roof Collar Ties Sizing

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.

Shed roof collar ties sizing.

The tie will go from one side of a roof rafter to an adjacent rafter but on the opposite side. 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. Framing any roof but particularly a gable roof low slope roof and cathedral ceilign roofs requires collar ties rafter ties and possibly a structural ridge beam to support the roof and to. The ceiling joists are in tension meaning that there are forces pulling on them from each end created by the roof loads.

This is on a conventional stick frame non truss structure as engineered roof trusses do not require collar ties from a framing material as they are tied together with metal. They do not have to be installed at each rafter pair and add visual interest when the roof structure is. Collar ties these create the same necessary structural triangle but do it a little higher up on the rafter. Collar ties as per current irc code are required to be at least 1x4 nominal material but are most commonly 2x4 s.

Step 3 install collar tie to roof rafters. The rafter ties are incorrectly labelled as collar ties. For example very long rafters in a relatively steeply pitched roof slopes above 6 12 for instance may benefit from a stabilizing effect if adequately connected collar ties are installed on every rafter pair. The 2015 international residential code does not require collar ties or collar beams.

Roof framing suggestions canadian guidelines. Collar ties may take up space in the attic of your home but they are there for a reason. Some of these can support the roof and prevent ridge sagging and wall spreading. Collar ties rafter ties tension beams structural ridge beams.

This means that if you secure one end of the collar tie to the left side of a roof rafter you will nail it to the right. Take the collar tie up to the attic and lift it into position to check for the fit. Collar ties prevent rafter separation and uplift. There are some exceptions however when collar ties might be useful even in a conventional attic roof.

This article excerpts from provides copies of roof framing suggestions from canadian building codes and the cmhc wood frame house construction guide.