Slab depressions?

[ron.sanpedro]

I am having trouble creating a slab depression. Or more correctly, there seems to be a number of ways to do it, and I am not sure which is best.
Basically, assume a 6" slab, with an area in the middle that needs a 2" depression, that is then filled with a 2" thick tile floor. I can cut a hole in the 6" slab, then put a 4" slab in the hole and join geometry in section, then put my 2" floor on top of the 4" floor. This basically works, but I now need two floor systems where the construction is really just a 6" slab with a depression. I can schedule both and sum the volume, but that is still a little goofy.
So what are others doing to address this? Can you just drop the 2" tile floor into the 6" slab? Will the volume of the tile floor be automatically removed from the slab? Or do you create some sort of depression family, that is nothing but a void form hosted by the slab floor, which creates the depression, then drop the tile floor in the void?

Any help with best practice here is greatly appreciated.
Thanks,
Gordon

[dpollard909366]

"Can you just drop the 2" tile floor into the 6" slab? Will the volume of the tile floor be automatically removed from the slab?"

This is exactly right. You draw the 2" tile part on the 6" slab (overlapping). Then you simply join geometry of the two floors. The tile depression will be cut out of the 6" slab automatically.

[Steve_Stafford]

If you join geometry between floors that are wholly within another it will "disappear". So you can't just put a thinner floor within another thicker floor and join geometry. You need to alter the floor first so you can place another floor within the depression. An in-place void floor will do it and a component family that is either face based or floor hosted will do the job too. Be sure to use symbolic linework for the edges since the void will not leave you with any edge you can snap to in the project.

[dpollard909366]

Steve - Try Joining it by picking the inlaid floor first - then it won't disappear

[patricks]

Or make the 2" tile floor actually 2 1/16" thick and place it 1/16" above finished floor. If you're not computing the volume of the tile floor (I would think you would only need to know the area there) then the total volume of the concrete slab would still be correct.

[Steve_Stafford]

Steve - Try Joining it by picking the inlaid floor first - then it won't disappearMakes no difference here...disappears either way. Is your inlay offset below the surface of the larger thicker slab?

[dpollard909366]

Steve - You are right it does disappear in section.... The tile section only shows up in plan if you join them.

[Steve_Stafford]

I don't see this either...can't you post an example?

[Dimitri Harvalias]

Hi Steve,

The posted example has three floors with inlay. The middle one is tile set into a generic floor (just a core), the bottom one is tile set into a multi-layered floor assembly.
The top one is not joined. Using join geometry, if the host slab is selected first then the inlay floor gets swallowed up by the host floor. If the inlay is selected first then it will show up nested in the host floor.

When joined the separate floor assemblies will only show up in section if the view is set to medium or fine, even if it shows correctly in plan and 3D. The slab volume is also adjusted properly.

[dpollard909366]

Thanks HCSL - you are exactly right with the medium and fine visibility - that is how you get the inlay to show in section.

Steve - make sure that the two floors are made of different materials, otherwise it will disappear no matter what when you join geometry.

-dp

[Steve_Stafford]

Okay...the issue I'm focused on is "slab depressions". The examples discussed and posted so far are not depressed beneath the surface of the "host". Join geometry does not create a void and depress a slab to show the other floor.

That's what I thought I was hearing in your suggestions. My read of the post is that it is asking how to accomplish this. Maybe I'm being too literal and the technique works fine for their needs assuming the two floor finishes are at the same finished elevation. :smile:

[Dimitri Harvalias]

Good point Steve. We are talking about a 'localised slab depression' to accomodate a different finish as opposed to a dropped slab or slab recess.
I'd probably create a parametric face based void family to create a depression where no fill is required, that way you can use one family for a variety of instances.
Always makes me chuckle when trying to clarify what we're saying is actually harder than figuring how to accomplish the task :lol: