Framing A Shed Roof With A Valley

In truth framing in the foundation and the walls adding doors and windows these are all relatively straightforward simple tasks.

Framing a shed roof with a valley.

On the common rafters the plumb cut is marked with a framing square for a 12 in 12 pitch 45 and cut square i e no bevel. Sheathing blocking is added along the valley and the sheathing pieced in for both roof planes. For our 4 x8 lean to example using a 2 4 rafter the depth of the birdsmouth is limited by the 1 3 depth of the rafter rule. Measure form the top of this line down the board to determine the line length or length of the rafter less the ridge.

Use a framing square to help lay out the notch based on the slope of the roof. The valley rafter is marked for a 12 in 17 pitch and then cut with a double bevel to fit into the ridge intersection. At the low end of the valley the subfascias of the two roofs are mitered with a block filling in the roof framing. To transition the eaves the horizontal fascia extends to the last rafter tail and a vertical return finishes the transition.

Position the square at the end of the rafter board with the tongue on your left and facing away from you. For many people the idea of having to do the shed roof framing is a little bit on the scary side.