The gable shed has a roof like a house so the roof trusses will have a peak in the middle. the truss sides will be equal in length and width to fit equally on the shed walls. finally there is a barn type or gambrel shed roof .. Design of the shed roof truss; since you’re making roof trusses for sheds, you must know at least some of the basics and the elements that you need for building your design using your roof truss plans for sheds. the basic elements that you need on how to make roof trusses for a shed include the following:. A mono truss is a one-sloped truss that forms a right angle triangle. a mono truss roof allows for more sunlight and visual space, proper drainage and relatively cheaper. it’s often used for sheds, garages or extension of an existing roof. 2. mono scissors. it’s a variation of the scissors truss and used in residential as well as commercial.