Purlin Roof Structure Names

Purlin plates in wooden construction.

Purlin roof structure names. But a purlin is applied directly onto the roof rafters running perpendicular between them while a batten is nailed to roof sheathing or applied over an existing roof for installation of a new roof. A purlin plate in wood construction is also called an arcade plate in european english under purlin and principal purlin. In the roof space as the name suggests the ridge board is the length of timber which runs horizontally along the apex of the roof. The cos of the purlin spacing is because the load on the purlins is vertical and the purlin spacing is with the run of the roof.

By supporting the rafters they allow longer spans than the rafters alone. The roof structure above can be seen near completion near the end of our roof dormer types article. This beam is known as purlin. This support is usually a beam which is protected under the rafters at a point between the ridge and the wall plate.

Internal roof elements to consider during loft conversions consist of a number of sub structures such as ridge boards rafters purlins joists wall plates and steel beams. Under purlins were typically propped off internal walls. A composite decking made of solid materials it resembles real wood and particularly strong and stable for bearing heavy load. For example an 8 x 4 under purlin would support the center of a row of 6 x 2 rafters that in turn would support 3 x 2 roof purlins to which the roof.

Purlin is used to reduce the size of the rafters and to make structure in economical one. Double roof construction is simple than other roof. This article and series of illustrated diagrams shows you all the parts of a basic roof truss king truss and queen truss. Below is a sketch of the original roof wall structural details for this building.

The two words are often used interchangeably and both are long strips usually wood used for the attachment of roofing material. A horizontal timber or metal resting at the peak of the roof the rafters and trusses are connected to the ridge board for a cohesive framework. Purlin plates are beams which support the mid span of rafters and are supported by posts. For sake of discussion we will assume a minimal roof snow load of 20 psf pounds per square foot and a 4 12 roof slope.

In lightweight timber roof construction under purlins were used to support rafters over longer spans than the rafters alone could span. The roof truss structure and design is integral to roof structural integrity and shape. The original roof was built using purlins beams extending between gable ends. The term plate means a major horizontal supporting timber.