Collar ties, contrary to popular belief, do not prevent walls from spreading.Where they are required, they should be installed on every other rafter where rafters are on 24-inch centers.Collar ties are probably not needed if approved metal connectors were used to fasten the rafters to the ridge.InterNACHI inspectors should not call out a lack of collar ties as a defect unless they know that collar ties were required in the jurisdiction where the home is located at the time the home was built. They may or may not be required, depending on the jurisdiction.In high-wind areas, uplift can tear a roof off of a house if it's not properly attached.Ĭollar ties and ridge straps should be installed on roof with a minimum slope of 3:12, a maximum wind speed of 100 miles per hour, and a maximum roof span of 36 feet. They must be spaced no more than 4 feet (1219 mm) apart. They must be at least 1 inch by 4 inches (25 mm by 102 mm). If collar ties or ridge straps are installed to connect opposing rafters, they must be located in the upper third of the attic space. Ridge straps are permitted to replace collar ties. Let's look again at the drawing above and review some definitions of basic rafter and roof framing terms.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. Roof slope also as inches of rise per foot of horizontal run. Length in inches of the rafter type for the corresponding particular Inch number along the blade's upper edge. To the right of each of these rafter type line names are columns of numbers under each SIDE CUT OF HIP RAFTER OR VALLEY RAFTER.DIFF IN LENGTH OF JACKS 24 INCH CENTERS.DIFF IN LENGTH OF JACKS 16 INCH CENTERS.
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