Split Pitch Roof Framing

The minimum roof pitch is 1 8 inch rise per foot of span.

Split pitch roof framing.

A sketchup model helps clarify how various rafters and framing components are assembled in an off angle hip and valley configuration. Explore framing complexities that result when roofs of two different pitches intersect. Repeat the process on the adjacent pitch side of the hip rafter using 5 3 4 12 on the framing square for a miter angle of 25 64298. Layout the square tail fascia miter angle as shown in this next drawing using 2 3 4 12 on the framing square.

Rafter layout with a framing square. Position the square with both the 8 inch on the outside edge of the tongue and the 12 inch on the blade on the upper edge of the board. Learn more about off angle roof framing. This example is for a roof with an 8 12 pitch.

The total rise is 12 inches or 1 foot and the span is 4 feet so the pitch would be 1 4 or a quarter pitch roof. It is also easier to insulate a roof with a greater pitch. Sheathing blocking is added along the valley and the sheathing pieced in for both roof planes. Position the square at the end of the rafter board with the tongue on your left and facing away from you.

Keep in mind the rafter approach can take several days and up to 3 weeks to complete a suitable frame. 1 8 pitch is given so 24 x 1 8 equals 3 or unit of rise in inches. At the low end of the valley the subfascias of the two roofs are mitered with a block filling in the roof framing. Figure 2 2 roof framing terms.

Line length is the hyptenuse of the triangle whose. To transition the eaves the horizontal fascia extends to the last rafter tail and a vertical return finishes the transition. 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.