Hip Roof With Collar Ties

A hipped roof can be designed without rafter ties or internal columns by using the wall plates as tension members and the roof deck for stability.

Hip roof with collar ties. Steel strapped at the corners. Rafter ties are used in the lower third of the rafter and resist outward thrust of gravity on the walls. Without roof deck the four hip members together with a four foot long ridge beam form an unstable structure when hinged at all six nodes. Collar ties are necessary to prevent separation of the roof at the ridge due to wind uplift.

In this how it works article managing editor debra judge silber explains the role of collar and rafter ties in the framing of a roof. By upper third here we mean one third of the length of the rafter from ridge to top plate. 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. Despite their intrusive appearance crossbeams sustain rafters against the outward thrust of roof loads.

Code required in some southern tornado prone states. Collar ties may take up space in the attic of your home but they are there for a reason. I know you can do it with a gable having a structural ridge supported on each end but what about a hip. Hip roof collar ties no you don t need collar ties positively connect the hip roof structure to the house section positively connect the rafters at the eave with h 1 hurricaine ties plywood sheath the rafters.

If there was no ridge beam the four hip beams would meet at a point and would form a stable structure if hinged at all five nodes. The bolts shown are not typically the way a conventional residential roof would be framed. Definition of collar tie in roof framing. Collar ties are required in the upper third of the roof system to provide restraint against the roof being pulled upward and outward from wind.

I expect you have a beam spanning the distance between the 3 foot sections to carry the jacks. The prescriptive rafter span tables on pages 4 and 5 are modeled on the tables in the irc and are subject to the restrictions for rafters as defined in both the irc and ibc. An engineer can design a roof with rafter ties on wider spacings look at the ridge and or wall plate as a beam if doing that. The 2015 international residential code does not require collar ties or collar beams.

Collar ties are used in the upper third of the roof frame about ever four feet to resist upward hinging in a violent wind that can take the ridge apart other wise. Is it possible to frame a hip roof without ceiling joists. In pitched roof systems such as hip roofs and gable end roofs collar ties and ceiling joists span across the ceiling space and obstruct the view.