Retrofit Improvements: Gable End Bracing
Because gable roofs present a large wall surface to the elements at the highest part of the house where winds are strongest, gable roofs are more susceptible to damage from high winds than hip or flat roofs. If the gable end is not adequately braced to resist the wind, the gable end wall can collapse under the wind’s force, leaving the rest of the roof susceptible to uplift and the house open to the elements. Inadequately braced gable ends are a common cause of major damage to structures and their contents in storms.
If the roofing is being replaced, improve the attachment of the roof sheathing by installing fasteners at 4” spacing throughout the sheathing for the first four feet of roof area from all roof edges. Install fasteners at 6” spacing otherwise.
If there is an overhang greater than 12” at the gable end (rake), and it is framed as a ladder and attached to the side of the house, it is best to remove it. It may be possible, however, to reinforce the connection by installing a lag bolt from the attic, through the gable end top chord and wall sheathing, into the 2x4 of the ladder frame. Rake overhangs in high wind areas should be constructed as outriggers tied back into the roof system for twice the length of the overhang, or as far as possible, and secured at the end with tie down hardware (e.g. joist hanger).
Gable ends will be similarly constructed in both truss-framed and conventional rafterframed roofs, thus added bracing details will be similar for either roof system. Roof trussed systems will typically have permanent lateral bracing installed perpendicularly crossing the center of webs exceeding 8’ in length. Rafters will typically have collar ties and purlins in the same plane as the rafters. The permanent lateral bracing of both systems is also provided by the roof sheathing and ceiling drywall.
There are several “Do-It-Yourself” approaches to gable end bracing for the handy homeowner who is able to gain access to the gable end through the attic, and the cost of materials for this retrofit is under $100. Otherwise, consult a contractor to incorporate this and other safety features into your next remodeling project.
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