Roof Purlin Details

The advantage is a reduced number.

Roof purlin details.

Using a combination of rafters and purlins is common. Purlin plate principal purlin and common purlin. In the past the majority of roof structures were of wooden construction but over the past 15 to 20 years there has been a vast shift away from wood to metal mainly steel roof construction. 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.

And roof pitches within the limitations given in this manual. Stramit purlins and girtsare manufactured from hi tensile g450 g500 or g550 galvanised steel with a minimum z350 galvanised coating 350g m2. They are made from 16 ga 0 060 min 50 ksi structural grade g 90 galvanized steel and specifically notched to fit over the ribs of the existing metal roof panels. Purlins traditionally support the roof deck cladding sheeting and are in turn supported by the principal rafters steel beams etc.

Minimum number of spans is 2 and the maximum span is 12 5m. 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. Roof hugger retrofit sub purlins are zee shaped structural members that are typically 10 to 12 feet in length. In architecture or structural engineering or building a purlin or purline is a horizontal structural member in a 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. A 2 nominal lumber thickness provides the maximum pullout values for both screws and nails when the fasteners penetrate a. It is often used in simple roof trusses such as in the shed porch and garage. Bridging and purlin accessories are manufactured from steel with a minimum yield of 300 mpa and galvanised coating of z275 or zinc aluminium alloy az150 coating.

Purlin is a well known material in the field of architecture structural building or structural engineering. With rafters it runs in perpendicular from the walls to the ridge while with purlins it runs to the ridge in parallel. Details on page 45 load tables on page 33 sleeved double span system sleeves are provided at all penultimate supports and are staggered at internal bays. In traditional timber framing there are three basic types of purlin.

Purlins girts and roof deck the substructure to which the metal panels are fastened must be properly spaced and sufficiently thick to provide a roof or wall system able to meet required design loads. The support system for the roof is comprised of ridgepole and rafters or purlins. It is a horizontal bar that used to support building at the roof structurally.