We are currently working on several parking garages, made from prefabricated concrete. It's a bit like using Lego. :)  And since I wanted to show how this works, I decieded to use "proper" structural elements: sctructural colums and trusses.

I started off creating a family for the floor slabs:

Easy enough, although you need to keep the extensions in mind. (As soon as I have this properly figured out, I'll post about it...)

Next I created a Beam System using this slab as a beam and put it at level height.

And here is where it got interesting, because I couldn't see the slabs:

Visibility of trusses is always an issue. Revit seems to think that they are only important to structural engeneers and that architects are not interested in how they look. So, if you're lucky, you get a thick line representing a small thing like a concrete truss 400mm wide and 1500mm high. An element that you'd propably not notice in real life anyway... :/

In my case, the solution was failry simple: I set the Bottom of the View Range to below the current level.

And, lo and behold, I get to see my truss floor: