Roof Rafter Layout

The table states that 2 x 6 rafters spaced 16 inches on center o c can span a maximum distance of 13 feet 5 inches.

Roof rafter layout. For every foot of run. Roof rise this should be calculated from the base of the roof to the highest point of the roof gable the peak. Draw a line down the edge of the tongue as shown in illustration b of the roof layout. Another option are 2 x 8 rafters spaced 24 inches o c.

There is no standard spacing it depends on what size of rafters you want to use and the span of your shed. To lay out a common rafter you need the pitch of the roof expressed in units of rise per foot of run. Looking through the center of the table we can find a couple of options. Rafter run outer wall this should be measured starting from the center of the roof span and then extending to the very edge of the exterior wall.

Marking the birdsmouth and the ridge board setback. Here the number is 941 86 inches. For a gable roof the run is measured from the centerline of the ridge board to the outside edge of the top of the wall. Here the number is 1166 66 inches.

In the gable roof example shown here a rafter with 6 in 12 pitch rises 6 in. For instance 2 grade 2x4s at 16 on center will span just over 9. For standard shed roof rafter spacing see rafter span chart. Run is the horizontal distance that the rafter covers.

Let s use this example and find a size of rafter that will work.