There is a timber wall on the second floor of an old Västerbotten house that needs to be dismantled. The bottom log of the wall is currently attached to the crossbeams with steel bands.
The height of the replacing steel beam should preferably not exceed 50 mm to be hidden in the floor on the second floor, so how many UNP 40 (or 50) S235 beams do I need to replace the log?
Do you know if it's safe to take down that wall? Log houses are not something you can just remove things from randomly. Are you located in Västerbotten? If so, you can get the numbers to a few different companies that work with log houses, so an expert can take a look before you do anything.
The roof ridges are separate, and we will save a small piece of the wall to access and properly align to ensure that the outer walls are not affected. Or what did you think could be the biggest concern?
I was thinking a little about everything. I have many friends who work with timber houses, so I've heard some horror stories about people who made "harmless" modifications which had extensive consequences. Therefore, I recommend that you let someone knowledgeable in timber frames take a look at your house. Since it is a Västerbottensgård, I thought you might be in Västerbotten, and I know a lot of people there who work with timber houses.
The house is located on the other side of the pond, in Ostrobothnia, Finland. But because they are quite similar, I chose to write Västerbotten house so people would understand what it's about.
I have had various experts visiting, partly from the local museum associations and a few carpenters. Since it was before the renovations started, the discussions about the walls were only superficial. But it was determined that you need to ensure that the wall does not start bulging outward at the gable by saving a part of the wall and securing properly at the corners. I will have another talk with them before the wall comes down, but I want to be able to present a plan to them on how I envision it.
The crossbeams basically support themselves, and we will insulate with cellulose insulation instead of sand/moss as previously used. So the construction will be lighter than it was before. However, since the ceiling in the room below seems to have settled by 2-3 centimeters, we want to try to lift it with threaded rods or something similar.
My estimate would be a maximum of 2 tons of weight. Then I don't know what safety margins should be considered, or how this is converted to the loads/bends that should be taken into account. So my thought was to find something that is at least as good as the existing timber.
You need a beam with a moment of inertia just under 500x10^4 mm^4. E.g., HEB 100. I don't have tables for UNP but I think it will be difficult to solve it with the small dimensions you have in mind.
