Need help creating a ceiling from a profile extrusion

[vanderloo5]

I decided the best way to create a roof with this truss, (attached), was to create the roof as a 2x6 rafter at a 2:12 pitch, raise it up off the plate, and then I want to place a ceiling underneath it to complete the truss profile. So I am now trying to figure out how to create the ceiling from a profile extrusion. Should I just do a model in place extrusion from a profile view? Or is there a better way? I can't really create the ceiling accurately from a plan view because it needs to flatten off where it sits on the end walls.

Thank You

[vanderloo5 · Accepted solution]

I ended up doing a model in place component with an extrusion to get pretty much what I wanted. Couldn't find how to delete this post but maybe it will help someone down the road.

[barthbradley]

Why don't you model the Ceiling as a Roof by Extrusion?  Or another option would be to shape-edit a flat Floor or Roof using Modify Sub Elements tools.  

Help | Create a Roof by Extrusion | Autodesk

Help | Modify the Shape of a Roof or Structural Floor | Autodesk

[barthbradley]

FWIW: Are you aware that you can use the Attach Top/Bottom tool to shape-edit a Flat Truss?  

[vanderloo5]

I wasn't aware but that is cool. Not applicable in this scenario I don't think. I did a generic roof with a 5 1/2" thickness. Then, under that I did a model in place ceiling component for the truss webbing/ceiling. This whole piece is at a 2:12 pitch and the part that made it a little tricky is that the top part, the 2x6 rafters, needed to overhang on both ends a little. The rest needed to be flush with the framing on both ends. Also added a standing seam curtain panel on the very top. This all works but not sure if there was an easier way. Oh, and the top and bottom of the 2x6 roof has 3' tails.

[barthbradley]

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@vanderloo5 wrote:

This all works but not sure if there was an easier way. 

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I thought you were using Structural Trusses.  That would be the easiest way, IMO/E.  More "I" in your "BIM" model too.  😉

[vanderloo5]

I am using structural trusses but maybe that's outside of my wheelhouse. Not up to speed on how to model trusses in a way that can be used in a roof, ceiling structure. I did attach the truss detail for the main span in a previous post and it's a 2:12 sloped truss joist with a 3' overhang on each end of the span. Don't know what the procedure is to model the truss, cover the roof area with 24" o.c. trusses, incorporate the gable overhang with just barge rafters. If you say it's easier I'd love to see it. That should have read in reply to @barthbradley

[barthbradley]

I told you and showed you how to do it above. 

In Plan View: Model the roof and the ceiling with System Family Roof Types via Roof by Footprint. Define the 2:12 eaves in Sketch Mode.  Adjust the Roof's Base Offset from Level to separate the two Roofs the distance you want.  Or simply, switch to Elevation View and move them apart from one another the specified distance. 

In Plan View: Insert the OOTB Pratt Flat Truss into the Project and place a single Instance under the Roofs.  Go to Elevation or 3D View and use Attach Top/Bottom tool to attach the top of Truss to the Roof and the bottom of the Truss to the "Ceiling" (e.g. Roof).   

TAB-Select the Top Chord of the Truss and change its End Extension Instance Parameter value to 3'-0".  

Array the single Truss.  

That's the basics.  However, if Trusses aren't in your "wheelhouse", why Model them at all?  You could simply model the top and bottom chords with Roofs and then use Basic Walls to represent the outermost vertical webs of the Truss -- attached to roofs via Attach Top/Bottom tool as mentioned/shown above. Optionally, you can join all the geometries together using Join Geometry tool. 

 

[vanderloo5]

Thank You. I'll give this a try.