Wall Heights not as reported in 'Element Properties'

[Damo]

I'm working on a new project where the wall Top Constraint is 1100mm above the Roof Level.

The floors, generic at the moment, are the 300mm Generic Floor. ( I note this in case it may be relevant).

I've just had to draw a new wall, same properties, and I noticed it was taller then all the others.

Measuring what has been drawn, all the original walls are actually 800mm above the Roof Level, although the Element Properties dialogue box reports them as having a Top Constraint of 1100mm above Roof Level.

I haven't locked any walls, heights or floors yet.

Whilst I would appreciate help in resolving this, I would also like to know what has happened. Is the fact that the walls are shorter by exactly the same depth as the generic floor a red herring or relevant?

TIA

Damian

[LMSmith]

Check if the walls are attached at their top in their properties.

[sfaust]

at the roof level, are you using a roof object or a floor object? The reason I ask is that floors are defined by finish floor level and hence extrude down from their associated level. Roof objects, on the other hand, are defined by bearing, and therefore build up from their associated level. If you are using a generic roof 300mm thick at the roof level, the top of the roof would be at +300mm in relation to the roof level. If the top of the wall were at +1100mm in relation to the roof level, it would be 800mm above the top of the roof.

If that is not the problem, there is also a property for roofs to be offset from their associated level...

[Damo]

.... are you using a roof object or a floor object? The reason I ask is that floors are defined by finish floor level and hence extrude down from their associated level. Roof objects, on the other hand, are defined by bearing, and therefore build up from their associated level....
As I'm just producing a schematic model to get the shapes right I've used floors throughout. ( Oops! ). So this doesn’t seem to be the problem.

I'll examine LMSmith's suggestion tomorrow when I'm back in the office.

Appreciate your reply though.

Damian

[shaunv68276]

Check the bottom constraints, sounds like some of those walls start -300 from level

[Damo]

Check if the walls are attached at their top in their properties.
This was the problem, thanks.
Detaching the walls allowed them to shoot up from 800mm to the correct 1100 above the level.

Any ideas how this little problem managed to pop up. Is it something to do with the way floors are created. I mean, on a simple building with no constraints, if I choose a wall to go 1100 above a certain level and then put in a 300mm floor, why should the wall shorten by 300mm?
(Although it is perfectly possible that I did something wrong)

[Mr Spot]

When you finished the floor sketch you most probably had a message come up asking whether you want to attach walls that go up to this level to the floor. You must have chose yes. :lol:

[Damo]

When you finished the floor sketch you most probably had a message come up asking whether you want to attach walls that go up to this level to the floor. You must have chose yes. :lol:
Mr. Spot, I think you are right, I did choose YES. What I'm now confused about is this:
If I said YES, that I do want the walls that go up to this level to attach, then why do walls that go beyond this level come down by the 300mm depth of the floor?

Am I missing something obvious to everyone else but me? :banghead:

[adegnan]

Mr. Spot, I think you are right, I did choose YES. What I'm now confused about is this:
If I said YES, that I do want the walls that go up to this level to attach, then why do walls that go beyond this level come down by the 300mm depth of the floor?

Am I missing something obvious to everyone else but me? :banghead:
Damian,

I assume that the interior partition walls are the ones you wan to attach to the floor. But the exterior walls are the ones that go up by the 300 mm difference?

Unfortunately Revit does not distinguish between those. It doesn't give an option for "attach interior partitions" vs "attach exterior bearing walls" although with the wall usage parameter it could probably be done sometime.

If this is the case, I'd recommend that you select yes to attach the walls, then you tab-select your chain of all the outside walls and detach them.

On the other hand, if you are talking about platform framing and the floor extends across the outside of the exterior walls, then you'd want it attached right?

But if you are talking about balloon framing or a curtain wall type of system, then your floor system should be built inside the exterior walls and should abutt them but not overlap them. They key decision is whether you have the floor and the walls overlap or not.

Just think about the construction, I am making some assumptions here and I may be off base. But if you model it the way it will be built, this method should work for you.

[Damo]

I assume that the interior partition walls are the ones you wan to attach to the floor. But the exterior walls are the ones that go up by the 300 mm difference?.
As this is just a schematic building, to get the external massing and finishes looking correct there are no interior walls at present.


They key decision is whether you have the floor and the walls overlap or not.
Appreciate your detailed answer, and I will keep this in mind for future work. However, I'm not sure this explains the 'logic' to my original query.

If I specify that a wall should be 1100 above the top constraint, and...."if I said YES, that I do want the walls that go up to this level to attach, then why do walls that go beyond this level come down by the 300mm depth of the floor?".... so that they are now 800mm above the top constraint. Why doesn’t Revit attach the wall, as requested, and also leave the top constraint 1100 above, as instructed?

Any comments, anyone?

[adegnan]

If I specify that a wall should be 1100 above the top constraint, and...."if I said YES, that I do want the walls that go up to this level to attach, then why do walls that go beyond this level come down by the 300mm depth of the floor?".... so that they are now 800mm above the top constraint. Why doesn’t Revit attach the wall, as requested, and also leave the top constraint 1100 above, as instructed?

Any comments, anyone?
All I can add is that now that you know how it works, you can make your decisions on what answer to select. Try and see if there is another floor or wall or roof level above the one you had the issue with... and you selected yes on the lower one... would it also lower that one?