Purpose Of Roof 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.

Purpose of roof collar ties.

They supplement the ceiling joists and prevent the rafter couples spreading. Collar ties collar ties are connections between opposing rafters at the upper one third of the roof frame area just below the ridge and they are required at a 48 4 maximum spacing which is every other rafter of a 24 on center spacing and every third rafter with 16 on center spacing. The 2015 international residential code does not require collar ties or collar beams. Contrary to popular belief collar ties are not there to support rafters or to keep walls.

Collar ties prevent uplift. The collar ties are used to strengthen the roof rafters to prevent them from buckling or sagging under the weight of the roof. Collar ties collar ties must be provided in all coupled roof construction. Rafter ties prevent spreading.

The most common reason for installing collar ties is to prevent rafters from spreading apart under load. By upper third here we mean one third of the length of the rafter from ridge to top plate. This collar tie roof is suitable for the span varying from the 4 to 5 5 this roof is used for a maximum span of 4 8 m. 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.

The design of collar tie roof provides greater ceiling height if it is required. Definition of collar tie in roof framing definition. Collar tie 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. However in a conventionally framed peaked roof like the kind you describe collar ties would probably serve little or no function since the attic floor joists serve as ties to prevent the rafters from spreading.

Where the rafter span is such that it requires support from underpurlins collar ties are fitted to opposing common rafters at a point immediately above the underpurlins. Collar tie is a colloquial term for collar beam.