Hello!
I have a house with an extension that basically consists of one large staircase. The staircase consists of 4 (!) straight staircases with landing platforms in between. I plan to replace this staircase with two floors and a spiral staircase between them. Below this is a basement. I am unsure how to attach the new floors to the frame.
My plan is to screw a horizontal ledger to the wall studs and then attach the floor joists on top of these horizontal ledgers. Does this sound like a good solution? If so, how should the horizontal ledger be dimensioned? According to the Lathunden app from Svenskt Trä, 45x145 C24 is sufficient for floor joists (2.5m span). I am thinking the horizontal one should be the same? Any recommendations on which screws and how many to use for fastening it?
