Gambrel Roof Collar Ties

Collar ties prevent rafter separation and uplift.

Gambrel roof collar ties.

The 2015 international residential code does not require collar ties or collar beams. A gambrel style shed roof offers the most storage space in the attic when compared to a gable or saltbox style shed roof. Like rafter ties collar ties are horizontal members that tie the rafters together and resist the force that tries to make the bottoms of the rafters spread horizontally and push the walls outward. 415 reservoir road whitefish mt 59937 1 406 253 5138 or 1 406 250 7054 fax 1 800 880 3178 quick framer gambrel roof 3 attach stud brackets picture 2 to base frame using measurements on plans measurements are to center of brackets 4 begin arch assembly by sliding 2 rafters into top angle bracket and secure with screws.

If your roof is already sagging by the pressure of the roof you can use the collar ties to help the roof rafters bend back into shape. Collar ties as per current irc code are required to be at least 1x4 nominal material but are most commonly 2x4 s. I can now analyze the whole roof system as a simple three hinged arch. There are some exceptions however when collar ties might be useful even in a conventional attic roof.

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. Compared with the traditional gambrel frame this method removes almost all of the complex analysis. The owner plans on using an engineered ridge beam and tells me that such a beam will eliminate the need for collar ties. Step 5 repairing sagging roofs with collar ties.

Use a roof jack on the sagging roof rafters to raise them back into position. Attach other 2 angle brackets to rafters and secure with. The upper collar tie does not experience the tension that the lower rafter tie is resisting if that tension is resisted in the upper third the roof is probably on the ground. In this case the collars.

The rafter ties are incorrectly labelled as collar ties. A friend has decided to put a gambrel roof on a 20 40 barn and has asked me to help in the framing. I ve never framed a roof before but when i asked for details i didn t see collar ties in his drawing. The prescriptive provisions of the building code require rafter ties on each rafter pair and collar ties every 4.

Measure for the collar tie and install it in the regular method. The guidelines i am about to explain for you outline the steps i use when i am designing my gambrel shed plans barn shed plans and small barn plans.