Trusses

[rookwood]

beegee;

<edited Post to begin New Thread >

BTW, I noticed your name on some very, very early posts regarding trusses. This seems to be my next obstacle. I am designing a custom residential project and out of the box see that rafters are about the only option for roof framing. I have downloaded several truss configurations from revitcity but they fail to load properly from the library. I suspect they may be quite old.

Many people were taking about an early tutorial that seems to no longer be available from an extinct site. What is the difference in constructing the roof from the BASICS tab vs. the Structural tab? Should I get accustomed to working on the structural members (i.e. floor joists, roof framing, columns, etc.) inside the STRUCTURAL tab?

thanx for your patience.

[beegee]

It shouln't be necessary to model all the trusses, just the one(s) that appear in section. In fact, I usually don't model them at all, just show something generic, since they are usually designed and constructed by specialised manufacturers here.

I'll see if I can dig up a parametric truss for you. ( or someone else may post one ?? )

It's a shame that RUGI truss tutorial has disappeared, because, although an oldie, still a goodie. ( Anyone who has a copy - please post it in our Tutorials forum )

There is no difference between the Basics and the Structural tabs for building a roof.



beegee;

BTW, I noticed your name on some very, very early posts regarding trusses. This seems to be my next obstacle. I am designing a custom residential project and out of the box see that rafters are about the only option for roof framing. I have downloaded several truss configurations from revitcity but they fail to load properly from the library. I suspect they may be quite old.

Many people were taking about an early tutorial that seems to no longer be available from an extinct site. What is the difference in constructing the roof from the BASICS tab vs. the Structural tab? Should I get accustomed to working on the structural members (i.e. floor joists, roof framing, columns, etc.) inside the STRUCTURAL tab?

thanx for your patience.

[Dimitri Harvalias]

Can't remember the version these were created in but you're welcome to them. As I recall they were pretty good families.
I also have the square cut version if you need them.

[Scott D Davis]

Did you check the Revit Exchange? Few Trusses there....

http://www.augi.com/revit.exchange/default.asp

[rookwood]

I have two choices. One is to continue with my attempts to search and fumble on my own and the second is to admit that I am only three weeks into Revit and ask for help.

Now then, my question(s) regarding roof trusses:

1. Almost all roof framing in my area is done with pre-engineered wood trusses. A real pain to detail and section in ADT thru building sections, etc. Therefore, in my eagerness and excitement, I have downloaded practically all truss families I have found on this site and RevitCity.

If I run thru a practice session and start with the default residential template and on the BASICS tab draw a 20' x 50' rectangular box with a generic wall, sketch a roof by picking the walls, my options for roof types is extremely limited. So I use a generic rafter type and complete the roof. When I try to load several truss families and edit the rafter roof system to a truss system, I am lost. I have not as yet found the method for integrating the trusse family into the roof.

2. If, and when, someone shows me how this is done, will Revit be intelligent enough to actually cut the trusses as required using a hip roof design? Even if it doesn't, it

[sjsl]

You can also buy the book:

Official Training Courseware
Autodesk Revit 6.0

Advanced

It has a complete tutorial about creating "Complex Family Creation" - trusses. It works in 7.0 as well.

At Amazon.

[Wagurto]

Rookwood:
It seems to me that you are expecting that revit will frame your roof truss automatically. I think that's not possible so far. What I do is to sketch my typical roof truss where I placed my building seccion. I use the drafting lines to do so. I am not sure there is a more advance method to do what you want to do. If there is one I would like to know.

[christopher.zoog51272]

What I do is to sketch my typical roof truss where I placed my building seccion. I use the drafting lines to do so.

truss families can be parametic 2d detail components, as well. We have ones for section and elevation. When used in combination with repeating detail tool, it goes really quickly.

-Z

[Joef]

I usually use one of the parametric trusses and place it in the building where I cut my section. If I happen to cut a section the other way I will copy it as many times as needed. I don't worry too much about the detailing of the truss because nobody is going to use my drawing to build it. At least they had better not :-)If I am in a hurry I will just draw in a truss in the section view with some dashed lines, and note it as usual on the plan.

Joe

[rookwood]

I don't expect Revit to design the truss framing system the way truss software does. However, are truss families to be used only as a 2D tool in sections, details, etc.? It appears so, judging from the comments i see here.

If this is true, then I guess I can't edit a rafter system and replace it with a parametric truss of whatever shape the way you edit other families (doors, windows, etc.).

Scott Davis posted a truss question with an attachment on May 14 showing an array of trusses in 3D view with a question on how to cut off truss overhangs at the wall. Were these trusses placed manually, and if so, how? Or were they part of a parametric truss layout which would show up in 3D views, building sections, etc.?

[J. Grouchy]

I don't worry too much about the detailing of the truss because nobody is going to use my drawing to build it. At least they had better not :-)
You never can tell with some builders...we had someone call us because they were scaling off our hand sketched rendering we used on the cover sheet and there was a dimension discrepancy. It's both funny and scary that some people are that stupid. Apparently reading the disclaimer immediately below the drawing was as much of a chore as actually building off the CAD drawings instead of 'eye-balling' it off the rendering.

[Allen Lacy]

I don't expect Revit to design the truss framing system the way truss software does. However, are truss families to be used only as a 2D tool in sections, details, etc.? It appears so, judging from the comments i see here.

If this is true, then I guess I can't edit a rafter system and replace it with a parametric truss of whatever shape the way you edit other families (doors, windows, etc.).

Scott Davis posted a truss question with an attachment on May 14 showing an array of trusses in 3D view with a question on how to cut off truss overhangs at the wall. Were these trusses placed manually, and if so, how? Or were they part of a parametric truss layout which would show up in 3D views, building sections, etc.? Depending on the project size, I work in one of two ways when it comes to roofs. If it's a small project, I will just use roof objects for schematics with a shingle layer, sheating layer & "truss" layer. Then when I'm doing CD's, I will make separate roofs for each layer which allows me to extend the shingle layer beyond the sheathing. You can do away with the truss layer at this point or not. I then use 3D parametric trusses that are placed at the roof level and adjusted to fit the sheathing roof. I get nice building sections using this method.

If the project is too large, I skip the 3D trusses (or use sparingly) and use 2D detail components and/or detail lines for sections, etc. The first method could be used on a larger project by using worksets (I'm trying this on a project now).

I will upload some of the truss families to the Exchange.

Edit: Added images

[Scott D Davis]

Scott Davis posted a truss question with an attachment on May 14 showing an array of trusses in 3D view with a question on how to cut off truss overhangs at the wall. Were these trusses placed manually, and if so, how? Or were they part of a parametric truss layout which would show up in 3D views, building sections, etc.?
I placed those 3D trusses (downloaded from the Revit subscription library) on the model, and arrayed them. They will show up in plan as 'stick' framing, and then they will show up in section/elev/perspective/3D as truss members.

[rookwood]

Scott,

How do you construct your roof and what type do you use. How is the truss family placed...manually on the floor plan? Do you manuualy place the trusses in plan view?

I have created a project template file with my standard wall sections already loaded. This is where I detail trussoverhang, heel height, wall types, etc.

[Scott D Davis]

In the case of the one I posted a while back, I built two roofs: One was the "shingle" roof, which was a thin topping roof consisting of a plywood sheathing layer and a shingle layer. This roof was on top of the structure roof, and the shingle roof overhung the structure by an inch all the way around, to simulate the finished rooof surface overhanging the eaves. The Structure roof was simply one layer, set to "wood" for a material, and set to the thickness of the top chord of the truss.

The trusses I inserted on a plan I called "roof framing" plan, which was a plan view, with properties set up to show the trusses as lines, and the walls below as half-toned. The trusses were inserted on a level that corresponded with their height. Once I inserted one and got it into the right position in the plan, I would array the others into position, or in a couple of cases, I just copied them.

HTH!