SURFACE LOAD FOR STEEL BEAM GRATING/GRID

Hi,
I am designing a steel beam grid (IPN240) and I want to apply a uniform surface load (10 kN / m2) to be taken by the beams.
Is there any way to do this without creating a slab on which to apply the uniform surface load?
As shown, no slabs, just beams.
Thanks in advance!
Ignacio