I'm planning to move my plumbing on the upper floor of my Älvsbyhus. According to Ä-hus, you can drill a maximum of 75mm and reinforce with plywood. When I asked if it's possible to pass a 110 pipe through the ridge wall, they thought it might be possible but had no calculations for it. I have to do it at my own risk. The beam is a Kerto beam that is 260mm high. What do you think? Maybe it needs to be reinforced with a glulam beam or multiple layers of plywood.
The big question isn't whether it's possible to drill a hole in it, that's clearly allowed. The question is whether you still have enough strength and stability left in the beam afterward. What their formula says is that with a 110-millimeter hole in a 260 beam, you lose 16% of the strength and increase deflection by about the same percentage. If the edge of the hole is closer than 260 millimeters from a supporting under beam, they guarantee nothing, nor if the load varies (fatigue risk, I guess).thomasd79 said:
So the question is how close you are to the design limit from the start. To make the hole, the beam should originally be over-dimensioned by at least 16% more than the safety factor, and adjacent constructions should be able to handle a deflection with a corresponding increased side load with the same margin.
--- Mats ---