Changing Isolated Footings Host

[jrichardson]

How do you change the isolated footing's host? Let me explain. We place isolated footings through out the building. In some cases the footings host is reference to Level and others a slab. Up until today I had thought that these footings were not really host based. I guess I assumed that I was placing the footing on Level 1 and giving it a minus distance from that level to locate it. In some cases I will create a top of footing level to lock the footing to.

Anyways think I would like all my footings host to be based from the level not the slab. How can I change this. When I place the footing originally I do not get the option to specify the host. In proprieties it is grayed out and set to "none". Once the footings are placed I can change the host via the "Pick Host" button. This than tells me to "Pick a floor, surface, or level to host the component". I can not find anywhere how to select a level. Toggling to elevation view cancels my command. Any ideas, preferred methods of placement, or am I doing something wrong.
thanks,

[Tom Weir]

Hi,
I am trying to figure out how you got them to be slab hosted to begin with. I thought they would be constrained to the level by default. When I insert them they relate to the level, though like you say you can change the host.
How did you do that?

Tom Weir
Los Angeles

[jrichardson]

In my case I have a slab placed prior to placing the isolated footing. When I place the footing it shows up hosted to that slab. Give it a try and let me know. I will post an example if you can not duplicate. I have tried placing the footing with and without a column, on and off from a grid line but still same result. I can not find anywhere to set this prior to placing the footing. My only solution so far is to make sure my slabs are turned off when placing them.
thanks,

[Paul Andersen]

Hey Jamie, Thanks for pointing this out. I never noticed this before and was able to recreate it. If you go to an elevation or section view and select the footing you can use the pick host button in the option bar and then select the level. If you want to make sure that all your footings are hosted to the level you could preselect them all in plan or 3d view and then switch to an elevation or section view and follow the same procedure outlined above.

Now that you pointed this out I guess I like the fact that you can do this but I'm not too sure I'm crazy about it's default behaviour. I can see where this would be useful in that if you wanted your interior top of footings to be 2'-0" below top of slab and had several slab depressions or steps to deal with and didn't want multiple levels you could have the slab drive the top of footing. The reason I'm not a fan of this being the default host is that if you are not careful or don't know about this your slab winds up controlling your footings elevation and not the level as you would expect and will result in footings being at the wrong elevation if you change the levels elevation with the thought process that it will adjust all of your footing elevations.

[Tom Weir]

I'll be darned, I was also able to re-create it! I looked on one of my existing porjects and found some hosted by the level and some hosted by the slab. I usually put the slab in first, so I think what happened is that I erased the slab.

That could be a problem though when you think about it. Say the footings are slab hosted and the slab is depressed -2', with the footing -1' beyond that (-3' from the level). If for any reason I erase the slab, the footing reverts to being hosted by the level, and the footing moves up to -1'. That's not good

I do notice that the "bottom of footing elevation" still reads from the level and not the top of slab. that's good.

So I am definaely going to keep an eye on this and re-host the footings. And I see what you mean that if you turn the floor category off new footings can be placed level hosted.

Good catch Jamie...thanks.

Tom

[jrichardson]

Thanks for responding. Glad you could at least reproduce it. Both of your views, thoughts, and comments were exactly what mine were when I first saw it. I like it but people need to be aware of it and its placement and switching options could be tweaked.

My thoughts as far as placing and switching the host. Upon insertion it would be nice to have a switch that would set the host by level or by object. Doing this would eliminate more accidental placement. And as far a changing the host it would be nice to not have to switch to another view. Maybe have a list of levels to pick from or dialog similar to the selecting plane dialog.