Structural Floor vs Architectural floor when to use which?

[rspierenburg]

I know this has been discussed in the past but I'm still not very clear on best practices. We are just starting to use Revit Architecture 2014. I've noticed that there are structural components and similar architectural components, floors as an example.

Is there really any difference to using an Architectural vs Structural floor? Or would you use a combination of the two (ie Structural concrete floor with an architectural floor on top representing floor finish etc). In our area it is up to us to produce Slab edge drawings for the formwork people as opposed to the structural engineers. And to be honest I would say 95% of the structural engineers in our area wouldn't be using Revit or BIM yet anyways.

So ultimately my question is, as an architect that does slab edge drawings, should we be using Structural or Architectural floors or both, and for what reason?

Thanks,
Rob

[damon.sidel]

Well, I can't really speak to best practice, just our practice. Our projects are generally big enough that we separate the structure into another file and link it in, even if we're never getting a Revit model from the structural engineer. Much of our work is international and much of the structure is concrete. Therefore, our structural model, linked into the main file, is mostly structural elements: structural floors, structural columns, structural walls. In our main model, we add architectural floors for finishes. Another thing we do, which I think may not be the norm, is that our levels are always set to finished floor. We're architects and we prioritize the design intent; we care most about the surface one walks on. So that said, in our structural model, the structural floors always have an offset down and walls and columns have negative bottom offset.

There's one point of view and that's our most common approach.

[david_peterson]

If you're working with a SE that isn't using revit, use the arch floor. One of the differences between the struct and arch floor is where they will show up. When you change you discipline setting from Struct to arch, or vice versa one will display and the other won't. The struct floor also carries the embeded analytical model which you don't need.

[patricks]

We always model a floor representing the floor structure (be it a slab, slab on deck, wood framing w/ plywood, etc) with the floor level being the top surface of that structural element. We don't ever differentiate by checking the Structural check box for the floor element, but that's what we do. Various floor finishes are different thicknesses, whereas the underlying subfloor is pretty much always constant. So that is the level datum we use.

Then in a floor finish plan, we place floor finishes consisting of 1/8" floors of various materials, offset +1/8", on their own Floor Finishes workset that is off by default.

[martinezdesign]

A Structural Floor appears to have more structural parameters associated with them (Rebar Cover, etc.) that Architectural Floors do not. When the floor is structural in nature (such as a slab), I use a Structural Floor. If the floor is a finish (tile, carpet, etc.), I use an Architectural Floor.

I would strongly advise against offsetting the structural slab in order to have your datum levels accommodate the finishes. Rather, the top of the slab should be where the datum levels are located and finishes should be offset from that. The reason for this is because various finishes have different thickness (imagine the various thicknesses tiles, wood, carpet, etc. would have throughout the entirety of the project), and in order to accommodate the finishes, you would then have to break up your slab into all sorts of different types and offset them all differently. The contractors and BIM execution plans I work with would not allow this because it does not mimic typical workflows, neither in Revit world or the construction world. Contractors generally don't think "Hm...how much concrete do I have to pour in order for this carpet to accommodate the wood floor in the room next to it? Or the room next to that one?" with the only exception being certain tile because its assembly is very thick and you therefore must depress the slab in order to prevent door threshold/ADA issues.

Finishes on floors should then be modeled separately as Architectural Floors on the Structural Floor and offset from that. This way they can also be tagged and manipulated independently of the Structural Floor. For VG purposes in section, you could join the floors. The name of the finish could have the thickness in it to quickly know how much you need to offset it from the level. This way, if the finish changes, you simply change the offset of the finish itself, rather than trying to manipulate the structural slab, possibly resketch it to accommodate new floor geometry or thicknesses, etc.