Sunday, July 30, 2006

Vertically Stacked Partitions

On several occasions I've had a new Revit user "discover" Revit's vertically stacked partitions. They usually think this is the quick and painless answer to all their problems with exterior walls; changes in materials, water tables, etc... I usually then have to patiently explain why, even though they are conceptually a good idea, vertically stacked walls are in fact the devil incarnate (per our Autodesk Revit contacts) and that in the long run these wall types tend to cause more problems then they help solve. Though I have been told they are perfectly good and useful at an early conceptual phase.

However, I have to admit that just the other day I had an inspiration for where vertically stacked walls could in fact be very useful (though I don't make any promises because I haven't been able to use this theory yet). The idea cam up because a user was scheduling material quantities and I pointed out that numbers for GWB can be a bit hazy because of the way Revit typically handles both interior & exterior walls, and quite often there is alot more GWB in your model then the contractor will actually build.

It was then that I realized that we could use a vertically stacked partition for an interior wall where the GWB needs to only go up the ceiling (or just a little past). The image to the right shows my example. The left most wall is a typical partition with GWB on both sides of a mtl stud. In this case it goes all the way to the bottom of the floor system above. The wall in the middle is just metal studs, and the wall on the right is a vertically stacked wall type composed of the two walls to the left. In this cas the vertically stacked partition is named "Inteiror Stacked Wall - 8' Ceiling", the GWB partition is set to a fixed height of 8'- 6" so that there is a GWB overrun above the ceiling height. The metal stud partition is set as variable so that in section the structure appears to go all the way to the floor system above.

In a situation like this you would have to have a Vertically Stacked wall type for each ceiling height condition you have, however typcially a partition like this would be used in offices with no privacy concerns or light commerical; where you probably won't have very much ceiling varation. What is also nice is that even if you have multiple stacked wall types (for different ceiling heights), as long as you use the same basic wall type ot build it; in plan they will all tag the same!

1 comment:

Emily said...

I know this post was from some time over the summer, but I'm just exploring all these Revit links now from the wiki. :)

In the situation you describe (with interior gyp partitions where the stud goes to deck but the gyp does not), you could also vertically separate the pieces of the wall (thru edit wall structure). A separate toggle should appear for the gyp v. the entire wall. You should even be able to set the gyp height in the element properties dialog (I can't remember the exact terms it uses, but an instance paramater is added when the wall parts are separated). This way, you could use the exact same wall type everywhere and reduce the height of only the gyp section wherever you needed that condition, or wherever it shows up in detailed sections on sheets. This would de-necessitate the separate wall types for each ceiling height. However, manual modification of the wall would be necessary for every instance. So pick your poison I guess.

Also, I have found a good use for stacked walls, though I haven't employed it. I don't know where the devil is in this wall type, so perhaps I don't fully understand their capabilities (or lack there of). We had a curved wall made up of two curves. This wall was composed of 5 wall types stacked on top of each other. All was fine and dandy until we found a structural interference and the belly of the curve had to swell. I spent an entire day slowly, layer by layer, modifying this complex wall. It probably took a whole day because we had a similar condition mirrored on the other side of the building, but it had slightly different wall types. If this wall had been originally been created as a stacked wall, it would have been as simple as changing 1 wall.

However, my hindsight is 20/20... :)