How My Roof Need Collar Ties

Collar tie is a colloquial term for collar beam.

How my roof need collar ties.

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. My engineer spec d a 2x12 top plate yes on the flat on the perimeter walls steel strapped at the corners. There are some exceptions however when collar ties might be useful even in a conventional attic roof. Other facts about collar ties.

Check the attic so that you can get a better look at where the roof rafter collar ties will be installed. 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. The only time collar ties do any good is when they are specifically designed to be functional by an engineer or architect and are installed with meticulous care by the framer according to detailed drawings. They may or may not be required depending on jurisdiction.

Measure the distance between adjacent roof rafters so that you will know the amount of lumber to purchase. By upper third here we mean one third of the length of the rafter from ridge to top plate. In high wind areas uplift can tear a roof off of a house if it s not properly attached. Collar ties are necessary to prevent separation of the roof at the ridge due to wind uplift.

Collar ties must be at least 1 x 4 inches nominal spaced not more than 4 feet on center. Definition of collar tie in roof framing definition. I haven t done a calculation for roof rafters collar ties in a while and i m a little rusty. 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.

Measure the vertical distance from the top of a ceiling joist to the ridge of the roof and divide the result by 3 to determine the height of the collar ties. Collar ties are usually placed in the attic area of homes. I m trying to run some calcs on an existing roof that has 2x6 rafters 16. Rafter ties resist the forces caused by gravity loads that would otherwise cause the roof to pancake and push out the sidewalls.

2x6 collar tie is located about 30 below the bottom of the ridge board. No collar ties and the ridge was semi bearing as it was fixed at house wall i used it to frame a little tray soffit and they dropped some uplights in it. They are secured about three quarters of the way up the roof rafters.