F1 and F2 are the limiting performance capacities of the forces in the parallel and perpendicular directions of a building component. Which one is which direction appears in a guide in each TER or corresponding test reports.
There’s also an interaction between the 2 forces that cannot be exceeded which is also explained on the reports. it’s either a linear or parabolic interaction that requires the unity of both forces to be less than 1.0. This information is to be reviewed with and by a design professional for each project.
Last Update: March 3, 2022