How to fix gaps and align curved slabs and walls in Archicad

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An accurate model must match the segmentation between the two elements — when the slab and the wall have different curve resolutions, their edges may not align perfectly, causing gaps or overlaps.

This article explores two practical techniques to ensure precise alignment between curved slabs and walls. The first method focuses on matching curve geometry exactly, while the second introduces a slight offset for a more realistic representation of construction layers. 

Issue description

When modeling curved walls and slabs, their edges must align perfectly for a tidy, precise result. If the wall and slab use different curve segmentation settings, their intersections may not match, which can result in small gaps or overlaps in the model.

Challenge: slab passing through the facade finish

Solution

Method 1: match slab curve to wall geometry

1. Create the wall
   • Use the desired curved wall geometry

2. Draw the slab
   • Use the Polygonal Method to create a slab manually, making sure to match the wall’s radius and origin for precise alignment.

3. Use the Magic Wand for faster tracing (optional)
   • Instead of manual tracing, use the Magic Wand with the “Best Match” setting.
   • Go to Design menu > Magic Wand Settings.
   • Set matching Method to Best Match, activate the Slab tool, hover over the wall edge, press Spacebar to trace.
     
     
     
     

4. Check the Reference Line

• Match the Slab’s Edge with the Wall’s Reference Line, making sure both the wall and the slab have the same number of segments along the curve. This will guarantee accurate alignment. 

Method 2: slight offset to match structural core

While previous method focuses on precise adjustments, this method suggests slightly offsetting the slab boundary inward so that it aligns with the structural core of the wall, allowing the finishing layers to pass through uninterrupted, like real construction methods.

Result

Both approaches reduce misalignments and minimizes unnecessary detailing, helping to streamline the modeling process.

 

Solution: continuous connection between slab and curved wall

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These techniques were originally shared by Community member @Fra. If you’d like to explore the original discussion, click here to read the full thread!

This article is part of the ‘Tip of the Month’ series on Graphisoft Insights, highlighting valuable community-driven solutions for modeling challenges. Try these methods in your next project and experience the difference in model quality and efficiency.