A Guide to Selecting and Using Purlins and Girts
A Specifying Checklist
When specifying purlins, include:
- catalogue number (identifying section, shape, size, thickness, protective coating and material grade)
- length (calculated by the detailer, taking into account frame spacing, end laps, clearances and overhangs as required)
- hole details (for end connections and bridging). Additional holes may be specified for fly bracing, etc. Where possible, standard gauge lines and hole dimensions should be specified to speed delivery
- number required, and
- special markings to facilitate erection.
When specifying bridging, include:
- catalogue number
- purlin spacing centre to centre, and
- number required.
Fascia bridging and adjustable ridge ties are ordered in the same way.
Accessories
Components such as bolts, brackets, etc. are usually ordered by catalogue number and amount required.
The precise ordering procedure and the range of accessories offered may vary slightly from manufacturer to manufacturer, but the principles are generally the same.
A Complete System
Purlins made from GALVASPAN® steel are part of an economical building system that promises good service for years to come. You should make the fullest possible use of the complete system and its accessories, such as ridge ties, raking girts, girt hangers, fascia purlins and multi-purpose angle connectors.
Inspection
Inspection of purlin systems normally requires only measuring and visual checking.
- ensure the purlins meet the specification. This should be done soon after delivery and before installation, and
- visually check that bolts are correctly fitted, all bridging correctly installed and the whole system is neat and true.
