Roof trusses are installed on the home’s framing down the length of the home ... Builders add joists to rafters through collars and metal fasteners. Joists are placed along the ceiling, run ...

By contrast, floor trusses are used for floor framing and floor support. Typically, roof and floor trusses are made of wood or metal. They differ in terms of dimensions and may be sold as part of a ...

Hot-rolled steel purlins predate modern metal building systems ... rolled channel and I-beam purlins spanning the distance between roof trusses, a then-dominant type of primary roof framing. The beams ...