A building panel mounting system comprising a rail attachment strap, a rail, a rail attachment profile and a building panel. The rail attachment strap is connectable to a support structure, extends along a longitudinal axis and includes one or more rail support brackets. The rail is connected to the rail support bracket and extends in a direction which is generally perpendicular to the longitudinal axis. The rail attachment profile has an engagement formation removably connected to the rail. The building panel is connected to the rail attachment profile.