Why is roof live load unreducible? 1

[hetgen]

Consider a large steel roof with a truss girder that supports 600m² [ 6500ft² ]; the roof is inaccessible and located in a no-snow area. Why is the roof live-load unreducible in this case?

It seems conservative to design the girder with a full live load, according to the eurocode the total live load will be ~ 15.3 Ton [ 33,720lb]?

 

[hetgen]

Thanks again @steveh49 ... That is the answer!

I shouldn't waste any time on this.

 

[hetgen]

@MIStructE_IRE It is failing in strength (ultimate) combination.