Purlins, girts and eave struts are secondary structural members used to support the wall and roof panels. Purlins are used on the roof; girts are used on the walls and eave struts are used at the intersection of the sidewall and the roof.
Secondary members have two other functions:
- Act as struts that help in resisting part of the longitudinal loads that are applied on the building such as wind and earthquake loads
- Provide lateral bracing to the compression flanges of the main frame members thereby increasing frame capacity.
Purlins, girts and eave struts are available in high grade steel conforming to ASTM A 607 Grade 50 or equivalent, available in 1.5 mm, 1.75 mm. 2.0 mm, 2.25 mm, 2.5 mm and 3.0 mm thickness. pre-They come with a pre-galvanized finish, or factory painted with a minimum of 35 microns (DFT) of corrosion protection primer.
Minimum yield strength is 34.5 kN/ cm2