Your shed roof framing is not as complicated as you might think. if you are like most people who attempt to build a shed, you probably have a good idea of how to do everything construction wise. except of course the roof. floor framing, wall framing, and building your door are not so difficult. but what about building the shed roof? how in the. How to build a shed: building & installing roof rafters. how to build a shed roof step by step. sorry now that we've built all the walls are not gonna take a step back for a 0:07build the walls i. The fourth step in the how to build a shed series this tutorial teaches you the necessary steps to building roof rafters. from cutting the rafter parts out to building a jig and assembling the rafters! a rafter is one side of the rafter assembly. the rafter assembly is made by using an o.s.b. gusset.