topic Re: composite wall intersections issues in Modeling

composite wall intersections issues

Achille Pavlidis — Wed, 24 May 2023 06:58:15 GMT

In the sceenshots attached below, two composite walls made of the same building materials intersect. The difference is that the wider wall has en extra row of brick and insulation and air gap between the brick rows. As the two walls intersect, the inside plaster skin intersects correctly, but as you can see the outer plaster skins don’t intersect at all. Also it is preferred the brick row of the narrow wall to intersect with

Also the core skin of the narrow wall does not intersect with the outer brick skin of the wider wall. Is there any way to make this work properly?

Re: composite wall intersections issues

Barry Kelly — Tue, 29 Jul 2014 02:57:26 GMT

Your air gap and insulation Building Materials will need to have a lower strength than that of the brick in the single wall.

Barry.

Re: composite wall intersections issues

Achille Pavlidis — Tue, 29 Jul 2014 07:34:54 GMT

They have

Re: composite wall intersections issues

Anonymous — Tue, 29 Jul 2014 08:59:50 GMT

try to increase the priority of the air space slightly to see if that makes a difference, just tends to work sometimes

Re: composite wall intersections issues

Barry Kelly — Tue, 29 Jul 2014 10:11:13 GMT

The external plaster/render skin will need to be stronger than the brickwork.
Barry.

Re: composite wall intersections issues

Laszlo Nagy — Tue, 29 Jul 2014 11:28:14 GMT

I was thinking about how to do this intersection.
Because yes, we can increase the priority number of the Plaster to be stronger than the brick, but the horizontal brick still won't extend to the left brick skin of the vertical Wall.
So what I did is I created another brick skin into the horizontal composite. It is a zero thickness brick skin (it IS possible to set zero for skin thickness). This way both horizontal brick skins will connect to a vertical brick skin.
The only thing is that there will be a horizontal line at the top of the right brick skin of the vertical Wall, but we can place a fill over it. That is the closest I can get to it.

The other solution would be to model this Wall corner using a Profile and place that Profiled Column in the corner.

EDIT after further discussion: As it turned out zero thickness will not work in 3D, but a very small value like 0.1 mm or even 0.01 mm will.

Re: composite wall intersections issues

Achille Pavlidis — Tue, 29 Jul 2014 12:17:37 GMT

this is actually a very nice workaround!

It has some drawbacks, for example if placing an autotext label for skins, and I don't know if there could be any problems with quantity take-offs.

anyway, thanks Laszlo!

Re: composite wall intersections issues

Barry Kelly — Tue, 29 Jul 2014 12:39:43 GMT

I have been playing with this and agree Laszlo's solution is the best option.
It seems odd to me that skins (Building Materials) with lower strengths are not being cut by those with higher strengths.
The attached image should work but doesn't.

I haven't actually come across this problem before as we don't show finishes on our walls or insulation in our cavities so our wall composites are much simpler.

Barry.

Re: composite wall intersections issues

Laszlo Nagy — Tue, 29 Jul 2014 13:27:07 GMT

Hi Barry,

That is strange, it works for me.
Do the two 500 skins have the same Building Material?

Re: composite wall intersections issues

Barry Kelly — Tue, 29 Jul 2014 13:48:21 GMT

Sorry it does work - I had the external brick at 200 and the internal at 500 by mistake.
This is it fixed and without any zero thickness skins.
Strengths as per previous image

Barry.

Re: composite wall intersections issues

Laszlo Nagy — Wed, 30 Jul 2014 09:14:11 GMT

Barry,
I think this solution shown by your last attached image works because the inner brick skin of the vertical Wall is not the same Building Material (BM) as the outer brick skin (which is the same BM as the brick skin in the horizontal Wall).
As far as I can see, in Achille's original case all three brick skins are the same BM, in which case the horizontal brick skin will connect to the right brick of the vertical Wall and will not extend to its left brick skin. That is what causes the issue: that all brick skins are the same BM.

Re: composite wall intersections issues

Barry Kelly — Wed, 30 Jul 2014 09:29:18 GMT

Yes if all the skins are the same BMs then they will simply trim with the first skin that is the same or a stronger BM and then there will be nothing left to trim the other skins which may be weaker.
So I would not have the same BMs in different skins of the same wall.
I would have an 'inner brick' BM and an 'outer brick' BM with the outer skins generally being stronger.
The same with the plaster - 'inner plaster' and 'outer plaster'.

Maybe this is why I have never really had any problems (apart from the fact I generally don't model the finishes and cavity insulation anyway).
I do have double brick walls that are the same brick inside and out but the outside leaf is always stronger and I actually make my cavity the strongest of all as I always want my cavity to be continuous.

Barry.

Re: composite wall intersections issues

Laszlo Nagy — Wed, 30 Jul 2014 10:02:40 GMT

Yes, that is another way of doing it.

But what I am thinking now in general is that the bets would be if we were able to manually override how ArchiCAD generates these joints. So, for example, we could instruct ArchiCAD with a few clicks to extend that horizontal brick to the outer brick skin of the vertical Wall. That would provide a solution for all cases.

Re: composite wall intersections issues

Achille Pavlidis — Wed, 30 Jul 2014 12:34:26 GMT

I have to say that yesterday this tip was working, but today it doesn't...

for some reason when I set the extra skin to have 0 thickness, the wall shows OK in floor plan, but the core completelly disappears in 3D view...

Anyway I agree with Laszlo, something has to be done to allow some manual override of this joints in special occasions

Re: composite wall intersections issues

Achille Pavlidis — Thu, 31 Jul 2014 12:39:13 GMT

are you 100% sure that we can set 0 thickness skins?

I'm getting error reports every time I open a 3d window...

Re: composite wall intersections issues

Barry Kelly — Fri, 01 Aug 2014 02:12:25 GMT

It works in plan but not 3D.
Apart from the error message you will find the skin next to the zero thickness skin will disappear.

Barry.

Re: composite wall intersections issues

Laszlo Nagy — Sat, 02 Aug 2014 09:10:02 GMT

Yes, it is true, it doesn't work in 3D. I only looked at it in 2D.
If I set 0 for a skin thickness, it will be degenerated in 3D.
But I could set 0.1 mm, or even 0.01 mm for a skin, and then it worked in 3D.
At that thickness the skin is so thin it is practically invisible unless you zoom in very very close.