Hello knowledgeable people!
I have a 1 1/2 story house from 1901. The upper floor was renovated in the late '70s. I am now tearing out the entire floor down to the beams and plan to do it properly. The existing attic floor (the floor on the upper floor) consists of 170x150 beams with a center spacing of about 1170, total span of 8.5 m with a support wall that divides it into two bays with a free-bearing length of 3.2m and 5.3m. On top of this, there was a 25mm tongue and groove floor.
I am now considering adding extra joists between the existing ones to reduce the floor's deflection. The problem is that according to sizing tables I would need excessively large joists, and I don't want to build a higher floor since the ceiling height is already limited (2m to the collar beams). I had planned to put 170x45 in between the existing ones with a joint over the wall (can't get full-length pieces up). Is it worth it or just a waste of time? Possibly I could use 70mm. However, I can only find 70x220 which means I would have to saw them down first.
All tips and advice are welcome!
