Placing Floor at Structur not Finish

[ryan.87191]

Has anyone figured out a way to place a floor (with a finish layer in the assembly) on the Level line at the structure layer? It obviously allows that when placing a wall (core face: Exterior). Currently I have to offset the floor from the level line, the thickness of the finish. It allows us to build the floor with a elements on either side of the Core Line, but they don't seem to serve a purpose.

[kpaxton]

Currently I have to offset the floor from the level line, the thickness of the finish.OMG :shock: I wounldn't do that if I were you. You're just asking for potential coordination issues later down the road. I am assuming here that you are referring to having a finish layer in ONE floor assembly description...

May I suggest thinking of Floors this way - The grids and guidelines used in construction documents are (typically) always used to reference those things structural - be it framing, columns or floors. Regarding floors, we typically will have a 'Bearing level' which is where the structure may rest, then have the separate 'Finish Floor' level. From my recollection - even when we were hand drafting back in the day - this always referred to the subfloor/substrate level - never a finish level. Owner/clients will always (and you can quote me on this)... change their minds as to what type of finish they want. The subfloor (usually) will not.

There have been many suggestions here as to how to treat the finish, and I think there are a lot of users who have adopted the 2-floor method - one for the structural aspect and one for finish. There are a couple of advantages to doing this. The first is that it is like 'real life' in that you can describe the finish differently in each room, etc . This floor is then offset from the level line the thickness of the finish. Many different floor 'veneers' can be created and stored in the project or template. The second advantage comes time to doing the material takeoffs. With this method, you can get accurate readings for these materials- based upon how you sketched the floor, of course.

my 2 cents.
Kyle

[iru69]

So I'm confused.

I draw my floors as two parts - (1) finish and (2) substrate & framing. I have one level line. Which top of "floor" should I set at the level line?

Does some consideration have to be take regarding how doors and windows are placed and scheduled?

[ws]

Me too (confused that is ;-))

As most of my work is on existing buildings I'm wondering where I should set 'floor level' - although I suppose as it's existing it is less problematic?

[ryan.87191]

Thanks Kpax

I was hoping you wouldn't that at first. But you make some good points which I didn't see before. Being able to to change the finish room by room is a nice advantage. And we don't really do material take-offs here but that doesn't mean we won't ever and that is a good one too.

A lot of the time I don't even need to do this but in those few cases this makes sense.

Thanks again,

[ryan.87191]

So I'm confused.

I draw my floors as two parts - (1) finish and (2) substrate & framing. I have one level line. Which top of "floor" should I set at the level line?

Does some consideration have to be take regarding how doors and windows are placed and scheduled?

your level line should be set at the top your subfloor. Your finish on top. unless it's an extremely thick finish material your top of windows and doors are taken from top of subfloor.

[kpaxton]

So I'm confused. I draw my floors as two parts - (1) finish and (2) substrate & framing. I have one level line. Which top of "floor" should I set at the level line? Does some consideration have to be take regarding how doors and windows are placed and scheduled?No, It doesn't sound like you're confused - this sounds exactly as how I do it. Ryan was describing a floor system that included the finish within the floor family- and offsetting the entire thing so that the structure part of the system was flush with the level line. And he was pointing out/asking why is there this flexibility without greater level of control. I was merely pointing out that this could cause issues later on and that a two-part system - while not a do-it-once procedure - allows for better flexibility.

Since floors are created in a Top-Down manner, the level they would use is the 'Finish Floor Level' or 'Level 2' or whatever you call your floor level... the substrate and framing floor system is set to be AT and in-line with this level. The finish floor (tile, stone, etc.) is also set to this level, but is then offset (vertically, say 1/8" if you set your finish floor to be 1/8" thick) from this level. [SEE IMAGE]

No extra offset for doors or windows should have to be taken into consideration in this matter, unless you're using a finish flooring material that is relatively thick! Then certainly you might have to use an offset for that instance. For "normal" floor finishes - carpet, tile, vct, etc. - this works well. Again, build your model as the guys in the field build the real building.

Kyle

[iru69]

No, It doesn't sound like you're confused...
Well, I wasn't confused about separating the floor finish from the rest - I've been doing that for a couple of years. But I have been placing the top of *finish* at level height and offsetting my subfloor & framing 3/4" down. :Oops:

This hasn't really been a problem, since I just generically make all the finishes in section 3/4" (unless it's intentionally built up, like a shower pan), but I don't like the concept of that - and from a framing perspective, I think the level line "dimension" should be to the framing. But if you're building it like it is, then a finish wood floor is going to be 5/8" or 3/4" or whatever and that 1/8" of tile you're showing is going to be something more like 1/4" on thinset on 1/4" tile backer board. That's going to make section details look more realistic as well.

Maybe I'm making it too complicated?

Many families (plumbing fixtures, cabinets, etc.) can be set to a "host" floor, but doors and windows have a fixed "connection" to the level line. It would be nice if you could select a "host" floor for them that they're head height would be measured from, yes?

[modulor]

Using the "finish floor on top" method, new RA2008 families with Masking Regions disappear under the finish floor layer. Will we need to raise the reference planes in all those families?

[kpaxton]

Modulor- Actually, I've been using this method since r6 and haven't had any problems whatsoever in Families. In regards to the masking regions in 2008 - again, my experience has been different - ie. no problems. My toilets, sinks, column wraps, etc. that have the new masking regions show up just fine over the 'finish layer'. Are you saying you're having difficulty with this?

Irusun - well, I wasn't saying you were that confused. ;) It's my understanding that (at least the last 30 or so years here in the States) - it's the industry standard to refer to the subfloor as the 'Level' line - be it plywood sheathing or the top of a concrete slab. In regards to the plywood, it's assumed to be a part of the 'structure' anyway - as it's used not only as a substrate to hold everything together, but also as a diaphragm for lateral load and shear.

[iru69]

Modulor- Actually, I've been using this method since r6 and haven't had any problems whatsoever in Families. In regards to the masking regions in 2008 - again, my experience has been different - ie. no problems. My toilets, sinks, column wraps, etc. that have the new masking regions show up just fine over the 'finish layer'. Are you saying you're having difficulty with this?
I believe I've noticed this as well - I think it gets back to which "floor" the object is hosted on. If you have a two floor system, and something like a toilet family is hosted on the subfloor, the masking region will now be below the finish floor (assuming that the masking region was placed on the reference level plane in the family). But I haven't confirmed it.


It's my understanding that (at least the last 30 or so years here in the States) - it's the industry standard to refer to the subfloor as the 'Level' line - be it plywood sheathing or the top of a concrete slab. In regards to the plywood, it's assumed to be a part of the 'structure' anyway - as it's used not only as a substrate to hold everything together, but also as a diaphragm for lateral load and shear.
Completely agree. But hence the conflict between what works well for documentation (e.g. level lines at subfloor) and what works well for certain aspects of modeling (doors and windows off of finished floor). I don't mean to make you the standards bearer (I think you've already offered what you can, thanks!) - it's just something I'm trying to figure out the best practice for. I think I'm just going to have to live with my windows and doors not really being 6'-8" (or whatever) off the finish floor. :|

[dbaldacchino]

Very interesting discussion....in the CAD world, we always showed Finish Floor levels, but since most finishes were thin (VCT, ceramic tile, carpets) we never bothered drawing those. So in practice, we showed the top of slab at "finish floor" and the finish went above that. Structural never offset the slab down by 1/8" or 1/4" to account for finish thickness, and we never had a problem with it. All we cared for were slab depressions in case we had resilient wood floors, thick paver tiles not in thin-set, etc, which require a lot more installation depth.

This week we discussed how our workflow is going to be between our Architectural and Structural Disciplines. In Revit, I prefer to use actual sizes and not nominal (that's just a carry-over from hand drafting, when you couldn't draw that accurately anyway). So now I'm thinking that the Arch would start off a project with showing an entire floor made up of a 1/4" finish, substrate (whatever thickness concrete perhaps) and steel deck. Then, since Structural will always show structural elements only, they will copy our floor and use a floor with no finish and lower their level by 1/4" and call it something else, or offset their floor by 1/4" and leave it referenced from the Fin. Flr. level. Architectural will then replace this floor assembly with a 1/4" finish floor only, and the levels will remain the same (referencing Fin. Flr.).

The problem I see is that Structural is used to having nice round dims, which were possible when we ignored the finish thickness, but now we're going to see some fractions perhaps, unless we change the total structural slab from, say, 5" to 4 3/4".

On second thoughts (this post is taking me a long time to think about and type!) I can see issues with it. Your wall's base should bear on the substrate, and not the finish. So I would think that in the initial design stages, Arch. should model a floor with no finish. Then, finish floor slabs are built up (either offset from the floor level or by using a roof instead). This way you don't end up with finishes under your walls, which will skew take-off numbers. The thing I don't like about this approach is that now, even though we show Fin. Flr. level, the finish would be modeled above this line (similar assumption to what we do in CAD). It is after all how they end up building it, but it's inconsistent with how we're naming our levels, because we're really calling out Substrate levels and not finish levels. Hopefully, once we start using masking regions, this won't affect their behavior (since everything is hosted to the "Fin. Flr. level" and there's a 1/4" finish slab/roof above that).

We'll tackle roofs in a similar way. Most of our roof construction is a steel deck with 3" of rigid insulation and roofing. So we'd start off by modelling the whole assembly and once Structural takes over the structural components, they'll copy and replace this assembly by just a steel deck roof and we'll replace ours by insulation and roofing only (and offset it by the thickness of the steel deck).

I have now probably confused myself and others :) If you see flaws in this thinking, please fire away.

[modulor]

Yeah, it has always been confusing to me that the floor substrate is commonly referred to as "F.F."
I tend to think that the "bones" of the building should have the primary dimensions, and they should have wholesome numbers- no fractions. Finish dimensions should be secondary. Seems like Revit should allow placement of floors by "face of core", similar to walls.
When I worked at a structural office, we got annoyed by levels and dims to actual finish.

[sbrown]

I think both floors and ceilings need a location line function like walls and that is what you can chose as the alignment to your levels. Also what you can tag. For example a ceiling set at 8'-0" aff the struct is really at 8'-05/8" but you don't want to dimension it that way. In a floor you want your slab/subfloor at the level and you finish above that, typically. a location line would solve this.

[iru69]

I like the concept, but what about when you *do* want to measure from the sub-floor in a framing plan view, but from the finishes in a finish plan view.

It's been a while (long before Revit existed), but for instance, I worked on an very large interiors remodel (something like a 100K SF) that had dozens of ceiling height changes all measured from finish floor to finish ceiling (which was mandated by the client).

Since the ceiling tag is taking its point from the level line (sub floor) and not the finish floor, this would have presented a real issue (though one I could have lived with - man, I wish I had had Revit back then!).

[jeff.95551]

This is an interesting discussion. We keep things simple, and unless the flooring finish is really thick, leave it at the floor level, and let the contractor deal with the transitions. The place where I've seen people get burned by over-thinking it is stairs. Everyplace else, in reality, you've got quite a bit of room for adjustment, but if your stairs go from finished floor to finished floor and you put wood over that, all of a sudden your stairs no longer work - you have to adjust them. What's worse - a concrete multi-story building where you've got soundproofing above. The stairwells all go to finished floor (there's no finish, after all), and then you've got a 2" step at the soundproofing. I saw this happen on a real project. The drawings weren't great, but the contractor didn't think it through, either, and all of a sudden there was a huge claim. If everybody is thinking 'finish floor' not substrate, the likelihood of screwing it up is a little lower, because everybody needs to know what the finished flooring is...

[modulor]

If everybody is thinking 'finish floor' not substrate, the likelihood of screwing it up is a little lower, because everybody needs to know what the finished flooring is...Yup, that's the other side of the coin; It is understood among some builders that it's part of their job to work out the rough dimensions themselves.

[ws]

Just starting my first Revit project I'll take the 'working down from finished floor' thanks, it is probably the safest - I often have projects where the floor finishes can be 3" stone flags in the kitchen and 1" oak boards in the hallway - but all need to be at FFL.

Mostly doing extensions to existing that would seem to offer fewer opportunities for confusion.


FWIW our local builders seem to work down from FFL always, and it only gets messed up when the client changes their mind half-way through ;)

[tomnewsom]

We keep finished floor level at the main Level for that floor - this means that things like ceiling heights read correctly - important when the finishes buildup is 100mm or so. The structural slab is a seperate floor and is embedded in the exterior walls. Walls are attached to these floors. Finishes floors go up to the external walls and through some internal walls, which get Joined where needed.

[affdesco]

I also draw my floors as separate structures.... roofs too. But I first create standard floor and or roof... then after I create my floor structure with joists, rim, blocking and hardware I replace the orginal floor with only my plywood. If I want to add tile or ??? then I add another floor. This helps for locking, levels and especially my favorite... schedules. I do the same with the roof when I add trusses or rafter/joist framing, then change the original roof template to plywood with the roofing on it.

[rlwade.68242]

I have a question. I also use two floors for my models one for the structure/substrate and one for the finish. However, when i put the finish floor in plan it covers over the model lines. Any thoughts on the best way to solve this issue?

[rodneyf]

Simply select the model lines in question and then go to the element properties dialog box and then change their height to allow for the thickness of the floor.

[rlwade.68242]

Model lines do not have the option to raise their elevation.

[ws]

Just a thought...

Model lines seem to be attached to the level on which they were created.

You could create a non-plan level at the height you want and then just copy and past aligned to that level.

I've tried it and it seems to work.

[dbaldacchino]

If you're running 2008, couldn't you select the finish floor slab and make it transparent?

[Scott D Davis]

Model lines can be workplane based. Create a new workplane and draw your model lines there.