Wall, Slab & Roof Junctions issues, not connecting / ignoring material priority

[luke-asplan]

Hello Archicad Community,

Would anyone please be able to advise, 
We may be completely missing something with the program, or maybe its an issue others are having...
Relates to Wall to Slab connections, also wall to roof connections.

Wall to Slab.

drawn a wall that goes from gorund floor (GF) to first floor(FF) then FF to Roof.
we then added the a FF slab, it seems where there is 3 elements joining at the same place (gf wall, ff wall and slab) material priorities is being ignored at the wall junction.  (attached image 1). any way to change this? 
Only way we seem to see that working is if the slab is going through only 1 wall at a time or making it so the wall is in effect a multi storey wall, which then raises other issues... different subject (img 2)

roof connection best option we seem to have is using 'trim elements to roof shell', works mostly okay, but the insulated plasterboard is projecting to the outside of the building, is there a way to stop this happening? only way we get around it is either a gutter profile with some airspace to hide it or 2d over the section with a fill to hide. would be good if just using a wall and roof we could stop this problem.

any help would be great, thank you.

Operating system used: Windows

[Barry Kelly]

The walls/slabs should be a matter of building material strengths.

Stronger will cut weaker.

For the roof, yes you have to trim them manually.

If you don't want the internal plasterboard to run through externally, you need to cut it off with a Solid Element Operation or mask it in 2D sections with a fill.

Or hide part of it with your gutter trick.

The best way is to model the interior plasterboard as a separate roof.

Barry.

[luke-asplan]

Thank you, great help as always Barry.
I hope you are well.

It seems we are probably not missing anything as you are mostly drawing in the same way.

Thanks for confirming.

"The best way is to model the interior plasterboard as a separate roof."

We avoid doing this so that skin list label works correctly and only need one skin list label on a roof.

"The walls/slabs should be a matter of building material strengths.

Stronger will cut weaker."

This seems to work is the slab in half way up a wall. but if the ground floor wall, first floor wall and slabs all join at the same place then the material priority doesn't seem to quite work right, it cuts out the ground floor wall, but not the first floor, as seem on my image 2 the floor finish is still going into the wall which it shouldn't.
but if i lower the slab to be half way up a wall it seems to be correct.

Thank you.

[Barry Kelly]

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@luke-asplan wrote:

This seems to work is the slab in half way up a wall. but if the ground floor wall, first floor wall and slabs all join at the same place then the material priority doesn't seem to quite work right, it cuts out the ground floor wall, but not the first floor, as seem on my image 2 the floor finish is still going into the wall which it shouldn't.
but if i lower the slab to be half way up a wall it seems to be correct.

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I think this is just because of the way Archicad trims the walls.

The lower wall only goes up to the top of the floor level.

So when that slab trims the wall, the stronger core stops the interior wall skin as you want.

As the wall does not extend up beyond the top of the floor, the weaker floor finish is not cut and remains to the edge of the slab.

I am not sure if this should be classed as a bug or if it is intentional.

The wall above only starts at the top of the slab so there is no interaction at all.

The only solutions I can think of are to have one continuous wall spanning multiple floors.

Or place the slab so the top of the structure is at floor level (as they would build it), and the finish is above floor level, which is what would happen.

The the upper wall will trim the floor finish away.

I don't have the same composites as you, but this should show you the idea.

Barry.