What makes a gable roof what its higher pitch than ordinary roofs.
Gable roof roof bracing.
But a gable roof also requires some form of horizontal.
Gable end walls need to be well connected to the wall below and to the roof structure or ceiling diaphragm.
Longitudinal bracing members should extend the full length of the roof tightly abut gable and party walls and permit diagonal bracing to pass they may be lap jointed providing the overlap is nailed to a minimum of two trussed rafters.
Bracing a gable roof is an important part of making sure that it is as secure and as sturdy as it possibly can be.
In the attic go to the gable end and examine the area where the triangular wall meets the rectangular wall below.