Hi, I need to fit an extractor fan and core a 4 inch hole through the wall but due to the layout of the room there are only really two places it can go. One is under but slightly to one side of a concrete lintel and the other is under but slightly to one side of where a joist sits in a pocket. I'm concerned about weakening the support for either the lintel or the joist, I seem to remember there being a rule about how close a hole can be drilled/made in this area, can someone give me some advice? I've tried to highlight the position in the photos, green outlines the "feature" I'm concerned about and red is a potential site of the 4 inch hole.
Many thanks
Many thanks
