If you are building a storage shed and have made it to the roof you may be wondering how to build the shed roof. Shed roofs are often the hardest part of shed building because of the angles involved in building the shed trusses. But there is help. The angles and cut lines for shed trusses are actually quite simple to produce once you understand some basic concepts about roofs.
Roof trusses are simply a triangle of boards sitting on top of the shed walls. All triangles have 3 angles. One of the tricks to designing a shed roof truss is to cut the truss in half to create two smaller triangles. By doing this you will create a 90 degree angle at the center which makes it much easier to figure out the other two angles.
Most simple shed roofs are a 4/12 pitch which means that for every 12 inches that the roof goes horizontally it will go upward 4 inches. With this knowledge you will be able to make a design and draw the roof truss with the proper roof pitch. The best way to draw the shed roof truss is to draw it full size on the ground. Drawing a full size drawing of the shed roof trusses on the ground greatly aids in visualizing and transferring the parts that need to be cut onto the roof rafter.
After the shed truss has been drawn on the ground you will put a 2×4 rafter board on the drawing and transfer the marks for the ridge peak cut and the birds mouth cuts onto the rafter board and then make the cuts on the rafter with a circular saw.
Use this first rafter to as a template to cut out a second roof rafter. Place both rafters on the full size template that you drew on the ground and attach them together with a gusset. A gusset is a piece of O.S.B. that is nailed to both rafters at the peak. Now you have built your first roof truss.
Take the first truss and set it on the top plates of the shed to make sure it fits. If it fits properly you are ready to make the rest of the trusses for your shed.
There is a full explanation of how to build a shed roof at icreatables on the page How To Build A Shed Roof.