Wednesday, May 3, 2017

Soffit and Bulkhead Modelling in Autodesk Revit

In Revit, creating soffits and bulkheads have some challenges in terms of how line work and layers clean-up in ceiling plans, elevations and sections. Specifically, the main issue has to do with the fact that the finish materials (i.e. wall system Layers) cannot wrap at the top and bottom of a wall (see Typical Problem image). The following method is not perfect, but gets things a little closer to reality.

Typical Problem: two walls (vertical) and a ceiling (horizontal)
Start by creating a unique wall System Type with the word “soffit” in the name; this wall type will only be used for soffits and bulkheads. For this new wall type, add a Sweep to the bottom of the wall (see Solution image).
Solution: Add a sweep to the bottom of the wall 
When this wall is joined with a ceiling, the sweep will join with the adjacent finishes when they are the same material.

The gypsum board profile for the sweep can be parameterized, so you have one for each stud size.

Here is how it’s done…

Creating a Profile for the Sweep

First, create a simple Profile in the family editor. This profile should be set to the thickness of your gypsum board, and the length equal to the depth of your studs.

You can add parameters/dimensions to this profile and then create Types to accommodate various conditions.

Profile:  Simple profile create to represent the gypsum board on the bottom of the wall

Setting up the wall type

The next step is to set up a special wall type in your project (or better, template). Duplicate your typical wall type; this is the one you normally use for soffits and bulkheads in Revit now. Add the prefix “Soffit” to all the wall types to sort them in the Type Selector. This wall type could still be based on your standard wall type. For example: M3 Soffit, where M3 is the name of the typical wall type.

Now you need to edit the structure for the new soffit wall type. As seen in the Edit Assembly dialog below, you need to set the View option to “Section” to be able to work with Sweeps.


Edit Assembly dialog for soffit wall
In the Wall Sweeps dialog, you will employ the profile previously created and loaded into the project. Add a sweep to the list, select your profile and then position it so it aligns with the stud (side to side) and cuts into the stud (from the bottom) the thickness of the profile (note the image below). The Material should also be set to match the typical wall so the profile cleans up with the gypsum board Layer in the adjacent walls/ceilings.
Wall Sweeps dialog for soffit wall

Wall Function

Now that you have a separate wall type, you should set the type parameter Function to Soffit.

Soffit wall settings

Examples

The following images highlight the results of this effort.

The first image shows a bulkhead with two hard ceilings engaging it. The Join command was used to get the materials to clean up. If you want the hard ceiling framing to extend to the bulkhead studs, you need to manually edit the sketch in plan, and make the edge of the ceiling touch the edge of the stud Layer.

  • TIP: In this example, the stud layer was unlocked within the wall, so the gypsum board could be shown stopping apart from the wall stud layer.


Bulkhead with hard ceilings (joined)
This next image shows a bulkhead with two suspended ACT-type ceilings on each side. In this case, the materials do not match. So, even if the ceiling and “soffit” wall were joined, they would not clean up.

Bulkhead with ACT ceilings
The next example is a simple soffit. This shows a soffit wall with gyp. bd. only on a single side of the wall. The hard ceiling is then joined with the wall and cleans up as shown. So you might want separate “Soffit” and “Bulkhead” wall types.

  • FYI: all these ceilings were drawn with the Automatic sketch option.



Soffit condition

Not Perfect

So what’s the downside to this process? You get an extra line in the ceiling plan, which represents the back side of the gypsum board on the (soffit) wall. With lineweights and printing, this ends up looking more like a heavy line, rather than two lines (because they are so close together). I know of no way to get around this. You remove it manually, using the Linework tool set to Invisible. But that is a lot of work, and probably not worth the effort.

Interior elevations do not have this problem. They look great.


Extra line appears at soffit condition in RCP

TIP: Changing the value for Line Weight number 2 will adjust the way fill patterns print in Revit (Manage tab à Additional Settings à Line Weights). Be careful, however, as you could also change other lines which have been set to this line weight number as well.


3D view with a Section Box


Rendered 3D view with a Section Box

This workflow is easy to setup in a template and use in a project. Good luck!


2 comments:

  1. Yesterday I was thinking I need to re-investigate the latest methods for bulkhead joins, wake up today and see an email from BIM Chapters titled bulkead modelling! Something new to try.
    Thanks Dan!

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  2. Sure thing Damien. Let us know if you find any new tricks as you look into this!

    ReplyDelete