![]() ![]() Rafter ties are installed between opposing rafters, and they should be installed as close as possible to the top plate. The roof framing mock-up below shows a standard rafter tie. In many situations, you'll find that ceiling joists installed parallel to the rafters are intended to function as rafter ties. Collar ties, contrary to popular belief, do not prevent walls from spreading.Ī 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.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.They may or may not be required, depending on jurisdiction.In high-wind areas, uplift can tear a roof off of a house if it's not properly attached.Ĭollar ties must be at least 1 x 4 inches (nominal), spaced not more than 4 feet on center. However, in those situations when they are specified, collar ties or ridge straps are usually installed in the upper third of the roof between opposing rafters. The 2015 International Residential Code does not require collar ties (or collar beams). The correct phrase is actually “collar beam.” In this article, we’ll use "collar tie."Ī 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 tie" is a colloquial phrase that is used among contractors, builders and inspectors, but not usually used in construction or engineering documentation. Collar ties and rafter ties are examples of tension members.Ī tension tie is a structural member that is subject to net tension. ![]() Tension members are solid objects (or structural members) that are subjected to axial tensile forces, or tension. In physics, tension is the pulling force exerted by a solid object on another object. ![]()
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