Secondary Framing

The secondary members shall include Purlins, Girts and eave struts used to support the wall & roof cladding.  Secondary members have two other functions: they act as struts that help in resisting part of the longitudinal loads that are applied on the building such as wind and earthquake loads, and they provide lateral bracing to the compression flanges of the main frame members thereby increasing frame capacity and these Secondary Members are used as a side runners, eave struts, fascia channels, door posts window posts, rafter xstays, Column stays, base angles, and other miscellaneous structural parts.

 

Galvanized Iron (G.I) Purlins, Girts and eave struts are cold formed sections and designed in accordance with the American Iron and Steel Institute (AISI). “Cold–Formed Steel Design manual”. Min. yield strength of G.I secondary members is 34.5 KN/cm² and thickness ranging from 1.5mm to 3.2mm.

               

Open Web joist is another secondary member; the application of open web joist is as roof secondary member supporting roof sheeting panels and mezzanine joists in multi-storey buildings. It enhances the clear working space while reducing the main members.

Other secondary members are cable bracing, flange bracing, base angles, clips and other structural miscellaneous parts.