Tapered TJI's

[Scott Hopkins]

Has anyone had success with creating tapered TJI's in Revit?

[PeterJ]

In English please Scott.

[Michael Coviello]

if your talking about a roof/ceiling/wall condition; I've used voids to cut out the ceiling joist from poking through the roof.
If your talking about actually tapering the tji; I'd be very cautious since this goes against Truss Joist or Boise's mfr. recommendations.
Please explain more.

[gregcashen]

Tapered TJI = composite lumber joist from Trus Joist (a Weyerhauser Company) with plywood web and dimensioned lumber chords. The tapered variety has a top chord that is tapered to allow for rainwater runoff.

[PeterJ]

This is a quick doodle on how to achieve what you are after. It flexes okay, but I can't get the taper angle down below 6 degrees and I assume you would want this to work down to 1 or 1.5 for a flat roof situation.

I have come across limiting issues in families before and assume it is one of poor family manufacture rather than a bug in Revit so I am probably doing something wrong.

This one is very quick and dirty to examine the idea, you'd want to consider using imported profiles for the top and bottom chords so that there was no deformation of the top chord when drawn on the angle (its a sweep). Also I made it largely instance based rather than type based as I imagine it being copied and then the instance shortened to cut around an upstand or a different abutment. You might also want one based on top of fall height so you can have a flexible leading edge for changes in a front wall line.

Hope it helps.

[Scott Hopkins]

Peter,

Thanks for the help. I ended up using a combination of a sloped roof with a flat roof soffit. After joining their geometry, using the linework tool, and setting the same course fill, the totally assembly looks correct in section. I guess I'll worry about medium and fine views later.

[PeterJ]

No problem I only knocked that up to show you away forward. The trick, if you want to get into it is to use a symbolic invisble line as your angle reference instead of a ref plane, that way you can get tighter constraints on it.

Good luck