Answer:
Additional combinations of favorable permanent actions can be considered using the Combination Expressions window in RFEM / RSTAB (see Image 01) and Window 1.4 in RX‑TIMBER (see Image 02).
Question
I just have to calculate an open hall with low roof loads and, compared to them, relatively high wind loads. In theory, it is necessary to perform the lateral-torsional buckling design of the bottom flange. Unfortunately, the combination 1.0*G + 1.5*W is missing.
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