How to recognize a master wall (carrier) and how to make an opening in a semicircle?
For the amateur, there is no foolproof method to recognize a wall. All that can be said is that the outer walls are still carrying and a wall of thin thickness (50 mm) in the middle of the room is never carrier. Similarly, we can say that any wall that supports beams or joists at their ends is necessarily bearer. When in doubt, consult a professional before beginning an opening drill. For curved openings, the simplest is to make a rectangular opening on the desired maximum height, and reconstruct the semicircle after drilling, with plasterboard.
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