steel roof problem

[o_berdibek]

Hello. In the architectural project, what kind of path should I follow on the last floor where the steel roof is statically designed as a steel roof. When I delete the floor, interior columns and beams of the last floor and have it analyzed, the program does not create a diaphragm for the last floor. I'm waiting for your help

 

[mhanifiata]

If there is no flooring on the upper floor, it can be a solution without a rigid diaphragm. possible in this program. you can transfer the loads of the roof to the relevant elements. This is also in the program. I recommend you to fit the steel roof trusses to the columns. you transfer the biggest M,N,V effects of the roof to the static system. I think it would be more logical to do the upper floor flooring. because suspended ceiling etc. on steel is also required. also requires fire protection from below. If reinforced concrete flooring is made, you can form the roof as steel column + steel beam + steel purlin...