purlin layout design

Purlin is a horizontal beam or bar used for structural support in structures, most often below the roof. Purlins are supported either by the building's rafters or its walls. These are most commonly used in metal buildings, but in wood-frame structures, these also replace closely packed rafters. In steel construction, the term purlin typically refers to roof framing members that span parallel to the building eave, and support the roof decking or sheeting. The purlins are in turn supported by rafters or walls. For more details and information of purlin download drawing file.