Wall object too thick !!!

[Vincèn]

Hi

Great beginner with drawio, I try to use it to draw a floorplan. I got the original floorplan of the architect as a picture that is around 2 000 pixels side resolution.

I import the picture in drawio and then use the floorplan library to redraw the floorplan properly. Unhappy I have a problem with the wall object. Even if I setup it at 1 pixel wide, it's still too wide (in a factor of 2/3) for the thinnest walls on the floorplan. How is that possible ?

What do I do wrong or missed ?

Thanks

Vincèn

[draw.io Q&A]

In draw.io, the “Wall” shapes from the Floorplan library aren’t true 1-pixel strokes — they’re vector rectangles with a width that’s scaled relative to your diagram’s zoom and page scale. That’s why even when you set the line width to 1 px, they still look thicker than fine lines in your background image.

Here’s what’s going on and how to work around it:

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Why it happens

• The Floorplan wall shapes are filled blocks, not just stroked lines. Their “line width” property controls the border, but the body of the wall still has a fixed minimum thickness based on the shape’s geometry.

• When you scale the shape down, the wall thickness scales too — but the background image might be so high-resolution that even at “thin” settings, the wall is still visibly wider than the thinnest lines on your imported floorplan.

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How to get thinner walls

1. Use a basic line or rectangle instead of the wall shape

   • From the General shape library, choose a straight line, set it to 1 px, and draw it over the plan.

   • For filled walls, draw a thin rectangle and remove the border.

2. Scale your background image down before importing

   • If your floorplan image is 2000px wide but your diagram page is smaller, you’ll end up zoomed out, and 1 px in draw.io covers more of the image than you expect.

   • Resizing the image so that it matches your diagram page size will make line widths behave more predictably.

3. Ungroup and edit wall shapes

   • Right-click the wall → Ungroup.

   • You can then directly adjust the rectangle’s width to match your needs, bypassing the preset wall thickness logic.

[Vincèn]

Thanks a lot for your so detailed explanations and it answers all my questions :) so now I'll be able to do properly my floorplan in Drawio :)

Thanks again for all, best,

Vincèn