Trim to roof - greater control?

[Rastisan]

Hi,

I need advice with trimming the walls with roof in such a manner that I get a correct gable detail out of the box.

Here is my situation:

If I do the connect/trim elements to shell/roof i get the following result:

As you can se the trim is not correct because the wall should trim to the bottom insulation layer of the roof and not to the roofing layer.

If I do this via SEO (subtraction with upward extrusion) the result is a bit better but not completely:

Walls now trim to plasterboard lining. How do I achieve the desired result where walls would intersect the plasterboard's and end with at the bottom end of roof bottom thermal insulation layer?

Is there a way to numerically adjust the trim in vertical direction? Or can I control at which skin does the trim end? Does the "Type" parameter inside the Composites settings control this maybe?

Thanks and have a good day,

Rastisan

[Barry Kelly · Accepted solution]

With the connect/trim method, it relies on the strengths of the building materials you use in the composites.

Stronger BMs will cut weaker ones.

So the insulation BM needs to be stronger than any of the BMs in the wall.

You may find your self needing multiple insulation BMs - i.e. roof insulation (which is stronger) and wall insulation.

You might get away with the ceiling (roof) plaster being the same BM as the wall plaster.

With SEO, the wall will trim to the underside of the roof with subtract with upward extrusion.

And it will trim to the top of the roof if the wall is above the roof (trimmed with downward extrusion).

Building material strengths will not come into play.

Barry.

[Erwin Edel · Accepted solution]

We found that modelling the bottom (ceiling) finish seperately from the 'structural' part of the roof meets classification standards better and makes using SEO with upwards extrusion correct for the majority of connections.

Might not be the answer you were looking for, but it solved a lot of these connections for us.

[Barry Kelly]

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@Erwin Edel wrote:

We found that modelling the bottom (ceiling) finish seperately from the 'structural' part of the roof meets classification standards better and makes using SEO with upwards extrusion correct for the majority of connections.

Might not be the answer you were looking for, but it solved a lot of these connections for us.

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Yes, this is a good idea.

Generally the ceiling will stop inside the external walls, while the roof surface may extend out beyond the walls.

You will not want the ceiling on the outside of the external walls.

Therefore modelling the roof and ceiling separately is better.

Barry.

[Rastisan]

The method using intersection priorities worked well. However it opened new questions for me as a new Archicad user: Is it possible or how to set up these material intersection properties in a way that they will generate correct details of at least most of the typical positions. But this issue transcends this particular topic so Im opening a new one.

Thank you for explaining both methods,

Rastisan

[Erwin Edel]

For most building materials we have a variant that has a higer priority and a lower priority.

Especially with structural materials like concrete, bricks, steel etc we have a 'finish' version with a lower priority and a structural/load bearing version with a high priority.

For things like insulation or finishing board material we have a 'normal' version with a high priority and 'light separation' version with low priority.

Roughly outlined:

100s: terrain materials

200s: light separation finishes

300s: standard finishes

400s: foils, membranes etc

500+600s: exterior finishes (bricks, wood paneling etc) and interior non-load bearing materials

700s: both load bearing elements and insulation (insulation often needs priority over load bearing materials)

800-900s: high priority loadbearing materials that always need to be a hard barrier

999: SEO

[Rastisan]

Erwin, thank you for sharing your settings.

I found that foils, membranes should be in the 900 range to achive hydro insulation continuity at foundation.

Ive posted another message in this topic which deals with the issue more generaly,

Rastisan

[Erwin Edel]

I must admit we never model these, so this could well be. They are part of the standard template from the Dutch Reseller and we've just kept them in, in case we ever do need to model them.