Rafter And Purlin Roof

Purlin and rafter roofs timber sizes and construction details keywords.

Rafter and purlin roof.

The roof support system is a ridgepole and either rafters which run perpendicular from the top of the walls to the ridge or purlins which run parallel to the ridge. A rafter is one of a series of sloped structural members that extend from the ridge or hip to the wall plate downslope perimeter or eave and that are designed to support the roof deck and its associated loads. This type of roof is exactly right as it has a steep pitch and lots of clear space between the timber framework. Using a combination of rafters and purlins is common.

A common arrangement is a rafter and purlin system which combines purlins and rafters. Stabilization typically involves installation of a purlin system. If you see sagging rafters recommend stabilization by a qualified contractor. As nouns the difference between rafter and purlin is that rafter is one of a series of sloped beams that extend from the ridge or hip to the downslope perimeter or eave designed to support the roof deck and its associated loads or rafter can be a raftsman while purlin is a longitudinal structural member two or more rafters of a roof.

Besides providing support for the roof rafters and purlins add to the interior beauty so you often see log purlins and rafters that match the wall logs. With rafters it runs in perpendicular from the walls to the ridge while with purlins it runs to the ridge in parallel. The main difference between rafter and purlin is that the rafter is a structural members in architecture and purlin is a structural member in a roof. Rafter and purlin style roofs are usually found in properties built before the mid 1960s and they are absolutely ideal for those property owners who are looking to convert their loft.

Hip rafters are simply called hips and are shown here as brown. 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 rafter and purlin roof and shows the dimensions referred to in the tables above. In architecture or structural engineering or building a purlin or purline is a horizontal structural member in a roof.

Hip roofs have hip rafters which are oriented diagonally to the ridge and outside walls.