Hi,
You're probably using a wall to create skirting and you have overlapping reference lines of the main wall and the 'wall' used for skirting. I would recommend using beam for the skirting - you'll avoid the intersection issues.
You could also make use of 'Intersection groups' of layers. Place skirting on a separate layer and give that layer different intersection group from wall layer (e.g. 2) and it will not join with wall. (Don't use "0" it will not join with itself)
Łukasz Pietraszko
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