Construction Concerns: Roof Cantilevers

By Gregory Havel

Modern roof gables often have an overhang beyond the face of the gable. In truss roof construction, this framing is usually a cantilever attached to the face of the gable. Photo 1 shows the framing for the overhang nailed through the oriented strand board or plywood gable sheathing into the face of a truss.

(1) Photos by author.

 

Photo 2 shows the truss and gable overhang in place at the end of a house, braced with the rest of the roof trusses. Roof sheathing will be nailed to the trusses and to the framing of the overhang, which will tie the cantilever framing to the rest of the roof framing, thus making the framing of the overhang part of the roof system.

(2)

 

Photo 3 shows several completed gables of this type of construction, with the roof sheathing covered with fiberglass-asphalt shingles and soffit and fascia trim covering the framing. This type of gable cantilever creates concealed spaces that may or may not be interconnected with the roof truss space.

(3)

With a fire in the roof truss space, the roof sheathing may be weakened before it burns through. Firefighters close to the edge of the roof may fall if the cantilever fails. Firefighters on the ground close to the wall may be injured when the cantilever falls on them.

For a discussion of another method of framing gable overhangs, see the “Construction Concerns” article from February 2013 on emberly.fireengineering.com.

Download this article as a PDF HERE.

 

Gregory Havel is a member of the Town of Burlington (WI) Fire Department; retired deputy chief and training officer; and a 35-year veteran of the fire service. He is a Wisconsin-certified fire instructor II, fire officer II, and fire inspector; an adjunct instructor in fire service programs at Gateway Technical College; and safety director for Scherrer Construction Co., Inc. Havel has a bachelor’s degree from St. Norbert College; has more than 35 years of experience in facilities management and building construction; and has presented classes at FDIC.

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