We have 2 load-bearing walls on the ground floor (both located about 3m in from each respective outer wall, long side), the above calculation program only considers 1 load-bearing wall on the lower floor, and if I calculate with the entire span to size it, I need to go up to a glulam beam with a dimension of 115x315, which I think is a bit much since we only have 2.35m in ceiling height. Can I, in the calculation, since I have double load-bearing walls, halve the span I enter in the calculation program as the weight is distributed on 2 load-bearing interior walls, or am I making an erroneous assumption?
Furthermore, in these calculation programs, you can specify a roof pitch of up to 60 degrees, we have a mansard roof (broken roof) so the steepest pitch is 63 degrees, flattest I recall is around 24 degrees, how should I think here, i.e., what roof pitch should I specify? I have used 60 degrees today.
