SketchUp models are inherently hollow surfaces rather than solid solids. When Zorro slices a wall or a column, it will leave a visible "gap" revealing the empty interior. To fix this for professional rendering, pair Zorro with an edge-capping script like SectionCutFace or manually draw lines to skin over the open holes.
: Define two points to create a straight "cut" line through all visible geometry. Nested Geometry Cutting : By holding the zorro plugin sketchup 2021