Building a jig on the shed floor to make sure all the rafters are exactly the same. nailing on the gussets. this is the fourth video in our shed building series.. Design the shed roof rafters. after squaring up the shed walls the next step in learning how to build a shed roof is to design the roof rafters. this is simpler than it sounds. if you do not have a drawing of the roof trusses in your shed plans then the easiest way to design a roof rafter is to draw it out full size on the floor and then cut. Calculate the length of the rafters. the length depends on the pitch of the roof. rafters sit perpendicular to the long side of the shed, so they must be long enough to cover the width. measure the width of the shed between the outside of the exterior walls and divide that measurement by 2. next, consult the rafter formula chart..
Gable shed plans| roof rafters| page 12 make sure all truss are the same or else you will not have an even roof. 2
