Blech
Girts are stabilized by (sag) rods/angles/straps and by the wall cladding. Stabilizing rods are discrete brace members to prevent rotation of an unsupported flange of the girt. Sheet metal wall panels are usually considered to provide lateral bracing to the connected, typically exterior flange along the length of the girt. Under restricted circumstances, sheet metal wall panels are also capable of providing rotational restraint to the girt section.