Web24' residential common truss 4/12 pitch 40# model number: Price after rebate* $ 74 84. Websep 4, 2023 · roof trusses are essential components for supporting the roof of a building, and making your own can save you money and customize your design. Webour free roof truss calculator is an invaluable tool helps determine requirements for roof trusses, by considering span, pitch, load, and materials to provide accurate calculations. In this guide, we’ll walk you through the precise steps to plan, measure, gather materials,.