I'm redoing an old house and since it's so small (58m2/620sqft), I'm planning to make the first story a single room. However, I'm not sure if I will be able to make the ceiling/floor of the attic stable.
Currently the construction of the ceiling consists of 5x15cm (2x6 inch) joists. The longest a joist goes without support is 2,3m (7,5ft) in the current setup. It rests on a fireplace which I have demolished (pic related, the one that is further from the camera no longer exists). Would it be fine to replace it with a beefier beam and extend its unsupported length to 5,1 meters (16,1ft)? Or must I install a support post in place of the old fireplace? Keep in mind that the attic will also be used as a room, so it must be sturdy.
Thanks engineer bros.