trouble with trusses...

[wdm]

I'm trying to show a gable truss in Revit structure, but I'm having trouble with the top chord being shown 3/4" to high.

I only need a truss at the gable end, everywhere else is going to be ridge and rafter.

To create my truss, I simply loaded the Howe gable 8-panel, then clicked the truss button on the design bar, and spanned it between two beams. I set my truss height to be 6'-8", at first it took that height to the center line of top chord members, which made the top chords way to high. So I changed my analytical line from center of member to, top of member, and that brought my chords down to now being just 3/4" to high. But that's as close as I can get it.

Right now the peak of the analytical lines, are at 6'-8 3/4", even though my truss height is set to 6'-8".

Any ideas????

BTW, this truss is being framed out of light gauge metal members.

[kmarsh]

Hi,

What if you try the Howe standard truss and attach it to your roof (or if you don't have a roof, you could make one for the truss to attach to) Does it work then?

Thanks

[wdm]

I tried the Howe 8 panel gable to start with, and I also tried the Pratt 8 panel, they both did the same thing. I started out by creating roof joists using 8" metal studs for my roof joists, at 2'-0" o.c. To begin with I ran my last joist right at the edge of the building, and then had a column for the ridge beam to bear on. We decided it would be cheaper to have a 1 gable truss, instead of a cross beam and column. So I deleted the column, and the cross beam, and put the truss in their place. But the top chord of the truss is roughly 3/4" higher than the top of the joists. I need get the truss to be in the same plane and the joists, and the metal roof deck needs to past over top.

I already have the roof deck created, but I don't know how to tell the truss to attach to it.

Also, how do you normally create roofing? I used to slab command, and then set the floor properties to be one layer of 1.5" metal roof deck. Then added a slope arrow to give the decking the proper pitch. Is it hurting anything to have Revit thinking that it's a floor with slope, instead of being a roof? I couldn't think of any other way to create a roof deck. I would like to use metal standing seam, but I couldn't figure out where to load it from.

[jmctamney]

I tried the Howe 8 panel gable to start with, and I also tried the Pratt 8 panel, they both did the same thing. I started out by creating roof joists using 8" metal studs for my roof joists, at 2'-0" o.c. To begin with I ran my last joist right at the edge of the building, and then had a column for the ridge beam to bear on. We decided it would be cheaper to have a 1 gable truss, instead of a cross beam and column. So I deleted the column, and the cross beam, and put the truss in their place. But the top chord of the truss is roughly 3/4" higher than the top of the joists. I need get the truss to be in the same plane and the joists, and the metal roof deck needs to past over top.

I already have the roof deck created, but I don't know how to tell the truss to attach to it.

Also, how do you normally create roofing? I used to slab command, and then set the floor properties to be one layer of 1.5" metal roof deck. Then added a slope arrow to give the decking the proper pitch. Is it hurting anything to have Revit thinking that it's a floor with slope, instead of being a roof? I couldn't think of any other way to create a roof deck. I would like to use metal standing seam, but I couldn't figure out where to load it from.

You could just edit the profile.

[wdm]

You could just edit the profile.

Edit the profile of what?

[scowsert]

Edit the profile of what?

I think he means the truss profile.

I have yet to make a decent truss with 2008. I have the same problems that you're having.

[jmctamney]

I think he means the truss profile.

I have yet to make a decent truss with 2008. I have the same problems that you're having.

Same here. A trick I learned at this years AU was to just edit the profile of the truss. View the reuss in elevation, pick it and you should see an 'edit' button on the design bar.

[wdm]

I tried editing the profile, but I can't get it to work.

When I edit the profile, it puts me in sketch mode, so I pick the top plane button and pick my top and bottom points, for each side of the truss. When I click finish it brings up an error, saying that the truss reference must form a continuous chain of sketchlines. So I went back, used the bottom chord botton, and sketched a horizontal line for the bottom chord. I clicked finish again, and it brought up the same error. So I'm not sure what Revit wants me to do.

Also, I tried using the attach/detach top chord button, on the design bar, that looked like it was going to work perfect. When I clicked my roof deck to attach to, it moved the top chord down right to where it needed to be, but then brought up an error saying that it couldn't attach because the truss can't project to a surface or the attachment creates an invalid profile. I assume that error is brought up because i've got my roof deck meeting up at the peak, which is technically "projecting" over the ridge beam.

Also, if I create a truss out in the open, all by itself, why does it not show the top chords coming together at the top? It shows them cross-cut perpendicular to the roof slope, instead of being plumb-cut to form a peak.