Traditional Purlin Roof Construction

The use of purlins as opposed to closely spaced rafters is common in pre engineered metal building systems and both the ancient post and beam and newer pole building timber frame construction methodologies.

Traditional purlin roof construction.

3 lean to roofs less common. Purlin plates under purlin principal purlins and common purlins. Sips panels these panels are from sipco need to be craned into place. The longitudinal horizontal beam that is sitting on a post or the principal rafter of a truss and used to support common rafters.

The best way to transfer load is with a timber to timber joint a compression fixing. Exposed rafters are a feature of some traditional roof styles. There are two basic methods of pitched roof construction. Every member of a traditional cut roof is individually cut and assembled on site.

A truss roof using factory made trusses which are delivered to site complete and just erected. A common arrangement is a rafter and purlin system which combines purlins and rafters. Parts of a traditional queen post roof truss. The beams will typically be placed along the ridge at the eaves and halfway between the two where they are known as purlins.

In traditional construction spans of over 3 metres or so were often dealt with by adding a purlin. Purlins support the loads from the roof deck or sheathing and are supported by the principal rafters and or the building walls steel beams etc. A cut roof this is the traditional method of cutting the timber on site and building up the roof using rafters ridge boards joists and purlins etc the exact details being determined by the size of roof size of timbers etc. It is a very common form of construction.

In architecture or structural engineering or building a purlin or purline is a horizontal structural member in a roof. Once the purlins are in place the panels can be craned in in a matter of minutes. This is a large timber running at right angles to the rafters and usually positioned mid span. Traditional roofs work by distributing loads from the rafters down through to the wall plate and then through to the walls below.

In traditional timber framing there are three basic types of purlin. Nails bolts and screws create a mechanical fixing to stop uplift through wind etc. In architecture structural engineering or building a purlin is any longitudinal horizontal structural member in a roof except a type of framing with what is called a crown plate. They span from the wallplate to the ridge board providing a platform for the underlay battens and tiles.

Purlin in architecture structural engineering or building a purlin or historically purline purloyne purling perling is any longitudinal horizontal structural member in a roof except a type of framing with what is called a crown plate. Purlin plate principal purlin and common purlin. There are three types of purlins in wood construction.