Joining floors together causes the hatch pattern to dissapear

[billn]

Sorry folks, this is a bit lengthy, but I can't really describe it any other way, maybe take a look at the attachments.

I am creating a model in Revit Structure 2012 that is intended to be a model of a site that we are working on. This is a complex project so I am trying to create a site so that we can see a somewhat accurate depiction of the bedrock shape below the soil. There is no site model for this project being done by anyone else, this is being done by us, as best as is possible. I tried using the toposurface but it seems to be only a surface and is not what we need.

What I have done is created a floor that I called "soil" and I gave it a thickness and made the material soil and gave it a unique pattern. The thickness varies across the site.

Then I copied that level down in elevation and duplicated it to be "rock" and gave it a thickness and made a material called rock and gave it a unique pattern.

I then modified the shape of both floors based on the site survey of the soil and of the rock so that they would represent the site conditions.

The distance from finished grade to the top of bedrock varies across the site so I had to come up with a solution to fill the void space between the bottom of the soil level and the top of the rock level. To do this I copied the floor called rock up in elevation and made it's thickness similar to the top layer of soil. Then I changed it to soil so that it matched perfectly the soil type on top.

Now from the top down, I have a level of soil with a unique shape, I have a level of soil with a shape that matches the level below, and I have a level of bedrock as the base. This way, I can see the shape of the soil surface and I can see the shape of the rock surface with the lower soil level tight to the top of it. This is exactly what I want to see.

the problem I am having is that when I join the top level of soil to the lower level of soil the lower level of soil looses it's hatch pattern in section. If I reverse the selection, the top level looses it's hatch. The two levels are identical in every way that I can see. They are the exact same floor type and they have no graphic overrides but they just do not appear correct.

I also did the same thing to the rock. I needed to show a cut into the rock and the easiest way to do it was to create a vertical opening through the rock layer. The problem was that the rock did not have a bottom now. The work around was to copy the rock layer down in elevation to the bottom of the required cut, reset it's shape and join it to the original rock. That worked perfectly .

The weird thing is that all the floors were created from the original floor but only some of them join correctly.

I also have a PDF of the situation.
The image at the top shows the 2 soil levels at the top that are not joined with the rock below. The lower image shows the same thing after joining the top soil level to the lower soil level.
The 3D image shows what we are trying to achieve.

Any help would be appreciated.
Thanks,
Bill.

[billn]

I just noticed that there is one difference between the 2 soil levels.

The top soil level has one shape based on points given in plan with set elevations and the lower soil shape is the same as the rock below, which is not the same as the surface soil shape.

When I reset the shape of either soil level (floor) they join cleanly, I can also make them variable thickness and they join cleanly. The problem is that they need to be the shape they are to display correctly, and the variable thickness only affects the top of the floor and makes the bottom flat.

It seems that Revit does not like the fact that I am joining 2 floor shapes that do not match.

Has anyone found a work around for this?

[billn]

Ok, I just had a thought... if there was some way to give a floor a negitive thickness, this would not be an issue.

Anyone know a way to trick revit into allowing a negitive floor thickness?


Thanks,
Bill.

[AdamCP]

Revit has trouble joining complex floors sometimes. One behaviour is if you join two floors, and the second pick (the one that gets material cut out of it for the join) has surface modification, that one displays with a generic material in section. If you can't arrange things so you always select that surface modified floor as your first join object, then you have to get creative (or you can actually still just override in view the problem floor to display the cut pattern you want. That still works oddly enough).

Given that you are trying to represent a strata of soil over rock, remove the 'infill' soil object and change the surface soil object to 'varies' and its thickness so that its depth is a bit past the lowest rock level. If you then join the two, selecting the rock first, it will 'cut' the soil object at its surface, given they are different materials. The only problem you have then is the hatch pattern in the soil object, which as I said you can override in your views to bring back.

For the void, you'd be better off with an in-place floor void object. That way you can control the depth it penetrates your rock/soil layers, and even have sloping bases or sides. I've attached a small RVT with an example of all this.

Hope it helps.