topic Re: article on 3 methods of intersecting walls and slabs in Modeling

article on 3 methods of intersecting walls and slabs

Anonymous — Wed, 24 May 2023 11:02:05 GMT

I'm looking for an article the explained three methods of intersecting exterior walls and slabs (floors). At least one of the 3 methods gave details on how the intersection can be done so the section renders properly. I'd like to start using that method.
Can anyone point me to that article or give me some tips on how to model my walls and slabs so they render properly in the section view?
Thank you,
John

Re: article on 3 methods of intersecting walls and slabs

Anonymous — Fri, 11 Nov 2011 23:27:06 GMT

Hi John,
I model walls and slabs in this way:
1. Top height of the external walls is top plate of the bearing slab
2. External edge of the bearing slab meets the insulation skin of the wall
3. Then I use SEO....walls as target, slab as operator; Subtraction.
4. Finish floors are Composite Slabs on their own Layer. Their external edge is on internal skin of the External walls.

Re: article on 3 methods of intersecting walls and slabs

Anonymous — Sat, 12 Nov 2011 10:26:20 GMT

http://www.archicadwiki.com/ModelingRelatedWallsAndSlabs

Found this and although I'm unsure if this is what you were referring to I thought it relevant and interesting anyway. Never thought about using beams to model insulation. Interesting.

Re: article on 3 methods of intersecting walls and slabs

Laszlo Nagy — Mon, 14 Nov 2011 14:38:12 GMT

There is also another one:

http://www.archicadwiki.com/WallSlabIntersections

Re: article on 3 methods of intersecting walls and slabs

Anonymous — Mon, 14 Nov 2011 15:18:13 GMT

Thank you for the links. Both articles are helpful.
Right now I am experimenting (in terms of our CAD procedure) with modeling all of the floor and roof framing elements in 3D in a way that the 2D structural plans are automatically generated from the 3D model.
I'm interested in doing this so that I know that the structural elements really fit the design.
I'm also trying to do this in a a way that will also generate clean and accurate sections and elevations too.
I think that it is all possible.

Re: article on 3 methods of intersecting walls and slabs

Achille Pavlidis — Fri, 09 Dec 2011 13:49:33 GMT

After reading the two articles, and considering also the implications of using BIMx, I would like to ask:
How do you guys model the floor finish?
Using the composite slab is I think the best method both in terms of time/productivity, and also BIMwise as you can define the load-bearing structure from the floor finish

In terms of BIMx representation though you have then a single floor finish material showing in rooms that have actually a different material... What to do? Using a separate slab to represent the floor finish is an option but I think will cause a lot more work... Whats your take?

Re: article on 3 methods of intersecting walls and slabs

Anonymous — Fri, 09 Dec 2011 17:39:29 GMT

For starters, let me point out that I usually design buildings with concrete slabs.

The structural slab is modeled on it's own STR layer. Floor and ceiling finishes are modeled with independent composite slabs. This way, I can have different finishes in sections for different rooms.

It sounds like a lot of extra work, but floor and ceiling slabs are modeled with the magic wand.

Google translate this:
http://architruques.blogspot.com/2011/01/cortes-limpos-no-archicad.html

Re: article on 3 methods of intersecting walls and slabs

Anonymous — Sun, 11 Dec 2011 23:37:38 GMT

John,

Whatever method you choose, remember display order works in section views. Bringing the slab's display order forward, covers the excess wall nicely. SEO works, but I find display order more flexible in this case.

A 4th method not mentioned in the Wiki is to extend single story walls down to the top of wall of the story below. If so, change the walls' floor plan display to home story only.

HTH, Snap

Re: article on 3 methods of intersecting walls and slabs

Djordje — Mon, 12 Dec 2011 03:51:47 GMT

Krippahl wrote:
For starters, let me point out that I usually design buildings with concrete slabs.

The structural slab is modeled on it's own STR layer. Floor and ceiling finishes are modeled with independent composite slabs. This way, I can have different finishes in sections for different rooms.

It sounds like a lot of extra work, but floor and ceiling slabs are modeled with the magic wand.

Google translate this:
http://architruques.blogspot.com/2011/01/cortes-limpos-no-archicad.html

Not extra work at all. This modeling technique allows for the model to be used beyond the design and documentation phase. Construction wise, this is the only correct approach.

Re: article on 3 methods of intersecting walls and slabs

Achille Pavlidis — Mon, 12 Dec 2011 10:54:28 GMT

I don't want to argue against anyones work method, but how can you say this is not extra work?

I have tried myself this approach, and have reached to the conclusion that it adds a lot of extra work, first in any minimal wall alteration there is the need to change the slab that is the floor finishing. Also the magic wand works only up to a point... what happens in the space left by the door opening?

Also I don't know how to express this... but I think it goes against the philosophy of Archicad. I mean that AC has a lot of parametres in its tools like doors, windows and stairs that allow for the computation of floor finishing that in my opinion indicates that the "correct" way is to use composite slabs.

I have used this method up until now, but I found it to be problematic with BIMx that need full detail to produce the correct visual result

Re: article on 3 methods of intersecting walls and slabs

Djordje — Mon, 12 Dec 2011 11:32:12 GMT

Achille wrote:
Also I don't know how to express this... but I think it goes against the philosophy of Archicad. I mean that AC has a lot of parametres in its tools like doors, windows and stairs that allow for the computation of floor finishing that in my opinion indicates that the "correct" way is to use composite s

I said "construction wise". When the composite parts start appearing in calculations, and quantities can be extracted without Property objects, then yes.

As long as your model serves for the documentation and visualization only, and does not leave your office or is detailed out beyond the necessary, all is well with composites.

Re: article on 3 methods of intersecting walls and slabs

Anonymous — Mon, 12 Dec 2011 13:58:17 GMT

It is more work, but not much more. For recent projects it took me perhaps 10 to 20 minutes to model floors and ceilings, including the floor space inside the door. It does not require SEOs, which is always great for speed and mainly for exporting to other softwares.

On an early stage of design I do a single slab for all the floors and another for the ceilings, and only get into detail once the design is fairly stabilized. Still, you can easily manage design changes if you use smart layer combinations and the marquee tool, even if a wall or a door changes it's place. For instance, for ceilings I use the zones as references and not the walls.

I agree this is not the ideal workflow. Zones should be able to produce these and other finishes automatically (I know of the Interior Wizard Add-on, it is not quite what I mean). But I find the ROI quite high, when compared with other methods.

As for quantities, my experience is that Zones are the best way of extracting them for construction purposes, because they update automatically, take into account doors and windows, and are localized by compartment (a great way to control execution on site). So the method I described is not indispensable for quantity extraction, but for drawings, namely sections.

Re: article on 3 methods of intersecting walls and slabs

Achille Pavlidis — Mon, 12 Dec 2011 14:31:51 GMT

I tottaly agree. Zones are much more efficient for quantity take-offs, and the use of multiple slabs for the floor finishes is extra work.

So for what reason -other than visualization- is it best to use this method?

Re: article on 3 methods of intersecting walls and slabs

Anonymous — Mon, 12 Dec 2011 15:33:00 GMT

Not visualisation, drawing documentation. As far as I know, for buildings with concrete slabs, it is the best way to produce automatic section in detailed scales.

Using only compositions can get messy. For instance if you have 5 types of floor finishes, 5 different structural slab heights, and 5 different ceilings, you get 125 different combinations, i.e., 125 compositions. And a single project can have much more types of floor finishes, or even a LOT of different heights for ceilings.

On the other hand, having inner brick walls that are build on top of the structural slab means that you would have to use complex walls (with risen finishes) SEOing into the floor slabs. That is a complex profile/SEO situation, which will get you into a whole new slew of problems (zones, wall finishes, export into IFC, slowing the model down).

But if there is another way of cleaning sections up, hey, I will be happy to give it a try

Re: article on 3 methods of intersecting walls and slabs

Achille Pavlidis — Mon, 12 Dec 2011 15:38:44 GMT

But this kind of detail only shows in scales smaller than 1/50. For sections I use composites that are modeled with different slab thiknesses and a generic fill for the floor finish, that doesn't go into detail for the material as it is not required for the 1/50 scale.

Then on 1/20, 1/10 detail I draw the exact floor detailing.

Re: article on 3 methods of intersecting walls and slabs

Anonymous — Mon, 12 Dec 2011 16:17:00 GMT

For the 1:50 scale, and even 1:100, floor finishes thickness is relevant in sections. For instance, there is a big difference between a wooden floor and a linoleum, or a ceramic and a stone.

This could be something that is a localized problem, but in Portugal it is common to go into great detail even in those scales. Nowadays the drawings are also delivered in digital format, that allow zooming, so even for people with tired eyesight (like me) it is easy to read that kind of detail from a drawing.

Attached is a simple example of a 1:50 section.