Traditional Purlin Roof Construction

Purlin plates under purlin principal purlins and common purlins.

Traditional purlin roof construction.

Roofs and not for traditional purlin and rafter roof construction. They also provide a speedy construction reduce onsite labour and costs and are most importantly versatile and provide a form of flexibility as they tend to have the capacity for a wide range of roof coverings. In traditional timber truss construction purlins rest on the principal rafters of the truss. Nowadays finding a traditional roof being constructed on a new building is quite difficult.

They span from the wallplate to the ridge board providing a platform for the underlay battens and tiles. Building control guidance note purlin and rafter roofs timber sizes and construction details. There are three types of purlins in wood construction. Since warm moist air is able to meet cold timber care must be taken to ventilate the roof void to minimise condensation and the possibility of rot.

The overall construction of a traditional cut roof is to ensure that the load of the roof is evenly transmitted to the walls below. There are two basic methods of pitched roof construction. 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. Parts of a traditional queen post roof truss.

This house s roof construction used prefabricated trusses from turner timber. Purlin roofs and prefabricated roofs are the two common forms of roof structures. It s an l shaped house with two very different roofs one is a collar roof the other a purlin roof with rsjs forming the purlins see photos below. The rafters are the main load bearing elements of the roof.

All the figures are based on roofing tiles or slates laid on. The longitudinal horizontal beam that is sitting on a post or the principal rafter of a truss and used to support common rafters. 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. In traditional timber framing there are three basic types of purlin.

Once the purlins are in place the panels can be craned in in a matter of minutes. Purlin plate principal purlin and common purlin. Pitched roof construction. Traditional or cut roof.

The alternative construction is the traditional cold deck. By chance we came across this roof a few miles outside bristol. The traditional option is steeply pitched rarely less than 35. Here insulation is usually placed between the roof joists i e.