Rafter And Purlin Roof

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.

Rafter and purlin roof.

Purlin and rafter roofs timber sizes and construction details keywords. This type of roof is exactly right as it has a steep pitch and lots of clear space between the timber framework. Hip rafters are simply called hips and are shown here as brown. Building control guidance note purlin and rafter roofs timber sizes construction details created date.

A common arrangement is a rafter and purlin system which combines purlins and rafters. The support system for the roof is comprised of ridgepole and rafters or purlins. If you see sagging rafters recommend stabilization by a qualified contractor. 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.

With rafters it runs in perpendicular from the walls to the ridge while with purlins it runs to the ridge in parallel. 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. 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. 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.

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. Hip roofs have hip rafters which are oriented diagonally to the ridge and outside walls. Using a combination of rafters and purlins is common. 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.