Designing a Roof Truss is a hard work but building a roof truss is not even harder.The truss is the major component of a roof . The sheeting for the roof connects the trusses and supports the tar paper and shingles. The truss bears the majority of the weight of the roof and holds the structure together. Manufacturers use aluminium for the majority of normal trusses. A proper truss design for the truss is required to provide the correct height, pitch and length of the truss.but what exactly we will going to do ?RK tell you.  
Review the roof truss design that you have. Make sure you understand what the layout of the truss is. Before you start is the time to ask questions and clear up any uncertainties. Measure the length and cut each of the pieces to manufacture one truss. It is prudent to make the first truss before cutting all the aluminium for the trusses that you need. This allows for a change in the design and length of each of the pieces if the first truss isn't quite right.

Assemble the first truss on the ground.Make the measurements of the truss and make sure it is correct according to the design you have. This will ensure uniformity in the roof truss design.