In any house, building, or structure in process of erection or construction where the distance between the enclosing walls is more than twenty-four feet in the clear, there shall be built and maintained proper intermediate supports for the joists.  These supports shall be brick work walls, iron or steel columns, beams, trusses or girders of wood, or other material of sufficient strength.  The floors in all such houses, buildings, or structures in the process of erection or construction shall be designed and constructed in such manner as to be capable of bearing on all their parts, in addition to the floor construction, partitions, and permanent fixtures and mechanisms that may be set upon them, a live load of twenty-five pounds for every square foot of surface.  Every opening in such floor shall be railed all around with a substantial railing four feet in height.  Every owner, builder, lessee, contractor, or sub-contractor of any such house, building, or construction, or the superintendent or agent of any of them, shall see that all the provisions of this Section are complied with.