wall priority help

[Anonymous]

not sure i understand exactly how wall priorities work..what exactly would be the correct priorities for this intersection to be accurate?

[__archiben]

aggie463 wrote:
not sure i understand exactly how wall priorities work..what exactly would be the correct priorities for this intersection to be accurate?

back up a little . . .

do your wall reference lines meet? and are the fill-types for each skin the same?

regarding priority intersections, the principle goes something like this:
structures with a higher priority will block structures with a lower priority. identical priorities will cleanly mitre if they're the same fill-type. (i think . . . or at least hope). the reality is much different since archicad's priority system isn't flexible enough, nor thoroughly implemented, in order to cover all possible intersections.

i base my composite structures - and beams/columns - on the following priority principle...

0 - Finish : Secondary - wet finishes such as paint, plaster, etc
2 - Finish : Primary - dry/panel finishes such as boards, sheet cladding, etc.
4 - Thermal/Air Space - all solid insulation skins plus non-core voids, cavities and air spaces
6 - Membrane - solid membrane skins such as asphalt, rubber, sarna etc.
8 - Substrate/Strapping - boards such as ply, particle, MDF, etc. and straps, firring, top hats for fixing
10 - Cavity/Air Space - core-only voids, cavities and air spaces
12 - Wall Structure : Beam Priority - bearing elements such as solid concrete, timber & steel frames, masonry that beams intersect
14 - Wall Structure : Wall Priority - bearing elements such as solid concrete, timber & steel frames, masonry that beams abut
16 - High priority bespoke use - use for walls to manually override beam priority '15' and wall priority '14' elements

Beam Priority Values

1 -
3 -
5 -
7 -
9 -
11 - Beam Structure : Wall Priority - Secondary structural frame elements that abut structural (12) walls and columns
13 - Beam Structure : Beam Priority - Primary structural frame elements that intersect structural (12) walls and columns
15 - High priority bespoke use - use for beams to manually override beam priority '13' and wall priority '14' elements

Column Priority Value

12 - Structural Columns Only - Due to inflexible archicad column priorities, use column tool only for structural elements!

does this help . . . or confuse you more?!

~/archiben

[stefan]

Select the three walls and post that as a screenshot... This will accentuate the reference lines.

I have this to suggest to my students:

"When the reference lines connect, you get clean intersections. When you draw a wall against another wall, regardless of the side, ArchiCAD will possibly extend the wall's length to connect to the reference line.
However, for easy connectivity of interior and exterior walls, it is sometimes easier to have the reference line of the wall to the innerside, especially in cases where walls join at the interior corners."



"In this last example, the exterior composite walls at the outside have used the "offset" property of the reference line to place it at the opposite side then usual. This ensures that the interior wall has a reference line to connect to. The left example (which is the default in ArchiCAD) has no automatic solution to have a clean connection, so you'll see the line between the two walls appearing."

[Anonymous]

In ArchiCAD 9 wall intersections seemed to behave in a more or less predictable way. Composites usually intersected according to their fill patterns, which (usually) produced the desired result.

It seems that in ArchiCAD 10 things are less intuitive. I understand Stefans explanation about reference lines but this seems like an awkward workaround. Is there a better solution to get this to work? See picture.

[Anonymous]

The condition Stephan illustrates has been the same since version 3 and is the main reason I have always standardized on putting the reference line on the inside face of exterior walls. (James Murray: I assume you still do the same?). The advent of the Modify Wall add on has made this so easy to manage that I no longer have any reservations about the practice. (Though I would still love to be able to assign the reference line to any separator within a composite.)

Philip,

I'm not sure I understand what you are trying to do. Why are the interior walls extending to the inside face of the brick veneer (fire stopping?). If they really do need to interpenetrate as shown then the intersection would need to be accomplished either by using two separate walls to build up the exterior assembly (and require dummy window openings) or with profiled columns (probably the better solution).

[Anonymous]

Sorry for not explaining. The internal walls should actually stop at the inner face as you would expect but for some reason ArchiCAD is punching them through to the inner face of the outer leaf.
The reference lines are on the outer face of the external walls.
see picture of how version 9 did it:

[Anonymous]

And now Version 10 does this with exactly the same composites:

[Anonymous]

In that case you must have some skins intersection priority problem. Check your composites. I suppose it could also be the layer intersection priorities if the reference line of the exterior walls is at the inside face of the brick.

[Anonymous]

It must be the skin intersection priorities because in these examples all the walls are on the same layer. I go and study them.

[KeesW]

I am sorry to say this but wall priorities are a nightmare. There are so many factors that could affect it. Just a few from recent postings in response to this query:
*it could be the layer
*it could be the position of the reference line
*it could be the overall wall priority
*it could be the individual element within the composite wall
*etc!

Wow! And AC is supposed to be productive?

What happens when, within one wall, the priorities for the same wall have to be varied to suit different intersection conditions? Or can't that happen?

AC should be clever enough to predict standard situations in 'T' and '+' junctions.

If this can't be done, maybe the whole approach needs to change. For example, if one was to draw the core wall first, and then add the linings with cavities and different materials etc. One could do this now if Archicad didn't have an aversion to having different wall layers share the same reference line position.

Or default priorities could be automatically determined by the materials used. For example, internal plasterboard lining are always connected. Brick or block walls always connect rather than being interupted by a plasterboard layer. Note I used the word 'default'. The option to alter priorities should probably remain available for masochists, refined intellectuals, or those with lots of time working in a non-commercial environment.