Box beam gable framing new gable overhang is framed in the form of a box beam hanging off of a new layer of roof plywood roof sheathing cantilevered over the top of the 3 layers of rigid insulation.
Roof overbuild framing.
Over framing is when you frame a roof section on top of another roof section such as when joining a l shaped roof with each section at right angles to each other etc.
1 8 pitch is given so 24 x 1 8 equals 3 or unit of rise in inches.
Use of rafters trusses and a truss base polyline are demonstrated architectural home design software.
The exposed edges of the 3 layers of rigid insulation are no longer exposed.
If the unit of rise in inches is 3 then the cut is the unit of rise and the unit of run 12 inches or 3 12.
Below is a link to a roof plan with a section that is over framed see note 3.
Figure 2 2 roof framing terms.
A third gable roof is joined to a main roof in an overbuild remodeling situation.