Purlin Supports Roof

The roof deck is the wood panel ply board or metal sheeting that creates the surface of the roof.

Purlin supports roof.

The purlins of a roof support the weight of the roof deck. Purlin plates are beams which support the mid span of rafters and are supported by posts. 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. By supporting the rafters they allow longer spans than the rafters alone.

During the roof installation or re roofing process after the roof sheets are prepared it is time to support their framework by installing purlins. The term plate means a major horizontal supporting timber. Several kinds of purlins exist. When made of wood it is usually covered with some sort of weatherproofing and sometimes an insulation material.

Metal roof purlins are installed horizontally under metal roofs. Purlins are 2 by 4 feet and are installed much like metal roofing. Once your purlins have been fitted and a supporting framework has been created you should look to carry out an inspection before you continue work. The braces struts or kickers should be within every 4 and should not be at a greater than a 45 degree angle towards the roof slope lower side.

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. A common arrangement is a rafter and purlin system which combines purlins and rafters. The structure of purlin helps to shift some of the loads that put on the metal sheeting to the main building construction by ensuring that the whole things stay in their place and adding structural. Purlins can be fixed to rafters and all joins and laps should be supported by a rafter.

Purlins as shown in sample photos below are installed for rafter support. A purlin plate in wood construction is also called an arcade plate in european english under purlin and principal purlin. The purlins are supported by vertical or slightly angled bracing. They give added support to the roof and also provide a nailing surface for the end panels and drip edge.

Check the purlin framework is correct aligned and levelled and make any. Purlin plates in wooden construction.