Saludos, Luis, y bienvenido a archicad-talk.
Beams made with the beam tool can only be horizontal.
But, various beams in the library can be rotated. Since these other beams are library parts, they are edited differently than beams made with the beam tool of course.
I don't know what is in the INT/SP library, but in the US library there are a number of beams that can be rotated. With the object tool settings, switch to "Find library part" mode and search for "beam" (or if your library is Spanish, viga, I assume). I have:
Beam2_1 SE9 - a rectangular wood beam
Various steel beams - C Beams, HP, L, M, MC, MT, S, ST, TS, W, WT
There are also tilting beams/rafters in the Roofmaker library. You can draw your roof (or ceiling) at the 12 degree pitch, select the roof(s), start Roofmaker, and it will place the beams for you at the matching angle.
(I find the Roofmaker parts a little bit awkward to edit though, but try them.)
Finally, what if your viga is supposed to be round (log)? Inside the "Basic Shapes" object folder, there is a Cylinder object, that you can rotate to any angle. A smooth cylinder won't look much like a log, but at least it is round and not square.
😉
Hope that helps.
Karl
