Showing Ceiling Demo

[dbaldacchino]

I haven't posted a question in a while

I have not needed to show a portion of a ceiling to be demolished in Revit yet, but the day has come. I have a 2x2 lay-in ceiling and I need to demolish a part of it. In the CAD world, you would perhaps show the grid to be demolished as a dashed line. Well, in Revit it seems that this is not possible. The grid in a lay-in ceiling is obtained via a model surface pattern and you cannot use the linework tool to override its appearance And, we cannot specify the linestyle to be used in a pattern, so trying to create a special "demo" ceiling to represent it correctly is out of the question.

To demo part of the ceiling, I can use an in-place ceiling family with a void to cut through (or sketch the ceiling in pieces and demo the appropriate part). And I refuse to draw dashed lines...so not BIM! In this case it seems like we can model this condition accurately, but the representation of this condition on a set of plans is not there. The phasing and phase filters work on the perimeter of the ceiling, but not on the model pattern. Well, if I'm demolishing an entire ACT ceiling in a room, the dashed line woudn't show up because I have walls around it, represented by solid lines

So I guess I'll have to resort to showing a filled region to define the ceiling area to remain. I kinda answered my own question, but I was hoping to hear what other users are doing and hopefully, someone will also benefit from this post as it's not THAT unusual of a condition. I'm also hoping someone from Autodesk is reading our forums on this nice Sunday morning

[Mike Sealander]

Dave:
Thanks for posting this. You and I worked on a demolition issue about a year ago when the use of voids to demolish was discussed.
I am probably going very shortly to be in the same situation you are currently in. An interesting comment from our client: ACT is so cheap, you might as well take the whole old one out and replace with all new, rather than try to selectively demolish.
With this said, perhaps the best thing to do is to create ceilings that serve no other purpose than to show up on a demo plan. For instance, can you create a "ceiling demo" phase, and then create and demolish specific areas of ceiling wholly within that phase?
I think a big part of the ceiling issue is that Revit considers an ACT assembly one thing, not a collection of parts. For the same reason, you cannot selectively remove specific CMU from a CMU wall.

[dbaldacchino]

Hey Mike, yes Revit is seeing a compound ceiling as a series of layers, just as a wall (Revit doesn't understand masonry, coursing etc). These are depicted with surface and cut patterns.

It's very true that selective demo of ACT is probably not a great idea if you're only leaving a tiny bit. If you have a large open area, then it might be a different question. Besides that though, I would like the phase filter to somehow show the grid as dashed if I demo a ceiling. Or at least Revit should permit the creation of a certain representation (such as a special demo ceiling), or let us override with the linework tool. I could go the route of drawing my ceiling grid with whatever line I want, but what BIM-fun is that?

[twiceroadsfool]

Dave-

Ive been broaching the issue of Lay in Grid ceilings in our office, and this is one of the wose i have with the use of a surface pattern to depict such an item, instead of an actual Object Oriented solution.

This last week i was playing with using a small mass extrusion, and they a curtain system by face on the bottom of the mass, so that i can use the mullions as the T grid, and a curtain system panel for the lay in tiles. I suppose then i could make different tile types for lights, whatever... But its not a clean solution. I was inwardly hoping that id be able to substitute a ceiling type for a panel, the way you cna use a Basic Wall in a Curtain Wall Panel, but it didnt go that way.

Still, you may consider the curtain system as the representation for your needs currently. At least then, you could demo portions of it...

[dbaldacchino]

I guess we're all agreeing here that Revit's representation of this and similar conditions is falling short of expactations.

[twiceroadsfool]

Ceilings are a hot button issue with me, haha. I want all the same ceiling options that i get for walls and/or roofs: Ceiling by face, ceiling by extrusion, ceiling by footprint (ok, we have this one), and ceilings as inlays for Curtain Walls/Systems. (OR a similar ceiling tool).

The fact that i have to make a ceiling type to call DEMO for graphical representation is completely unacceptable. It goes against my belief of adding in a manual control for something revit already controls (phasing).

Grrr, dont get me started...

[dbaldacchino]

I won't get you started

I was actually surprised that I found it so limiting. I had to override light fixtures by element to show them hatched for those fixtures to be re-used...not a big deal really. After all, representations vary and it's hard to build in every permutation that users want I guess. Overall I was able to show it just fine. Just showed existing areas with a filled region on top and pointed to demolished ceiling areas with an annotation symbol. I'm using Generic Annotations and a Note Block to track demo keynotes. Sometimes you just have to quit thinking CAD!

[twiceroadsfool]

Definetely agreed. It has just always bugged me that ceilings work that way. When i build complex vaults and trays etc, i end up teaching people to use masses and Walls By face. Then they have a bunch of walls, which i guess works becuase one could make the argument that *technically* a guy ceiling is a wall laid on side... But i dont like playing that game, because it will screw with them if they never need to override and/or control visibility by object style, and the entire damn ceiling is made of walls...

[patricks]

I'm surprised I didn't see this mentioned already, but why not just create a custom model pattern of a 2x2 grid with dashed lines?

I made this in just a couple of minutes, plus a little time to troubleshoot why the dashes weren't showing up. I realized that spaces in model pattern lines have to be negative for whatever reason.

[dhurtubise]

You beat me to it Pat. Damn monday's
Cleanest workaround you can get, sorry Big D