Sagging floor joists

[ferroknegarn]

I have an intermediate floor with a span of 4.4x4.4m. The joists consist of 50x150mm at CC800mm. As you might understand, the upper floor flexes a little uncomfortably when you walk, and sags about 3cm in the middle. I have taken down the ceiling on the lower floor. I am planning to add more joists from below between the existing ones to make it CC400. Attach 45x70 under the existing 150 joists. Then the plan is to add spacers and then huntonit panels in the ceiling. If I choose 45x220 joists, the ceiling will be lowered about 90mm from before to a height of 2.32m, which I am worried might be too low when finished. This is a living room in an "old" house.

Am I worried unnecessarily about the ceiling height?

I am interested in how others would think in the same situation?

 

[Messier1994]

I have a middle floor with a span of 4.4x4.4m. Joists consist of 50x150mm CC800mm.
As you might understand, the upstairs sags a bit unpleasantly when walking, and hangs down about 3cm in the middle.
I have taken down the ceiling on the lower floor
I plan to reinforce from below with more joists between the existing ones so it becomes CC400. Put on 45x70 under the existing 150joists. Then the idea is to make it a bit less tight and then huntonit panel in the ceiling.
If I now choose 45x220 joists, the ceiling is lowered about 90mm from before to 2.32m in ceiling height, which I'm worried might be too low when finished.
This is a living room in an "old" house

Am I worried unnecessarily about the ceiling height?

I am interested in how others would think in the same situation?

Not an expert, but I wouldn't have taken 45x220.

I would have reinforced it 40cc with 45x145 — and — then glued — double — 22mm MDF flooring on the inner floor, with very generous amounts of polyurethane glue, especially on the joists.

But it would be interesting to hear what an expert says.

 

[Oldboy]

Is the space above used, or is it possible to stiffen the floor from above?

Regarding ceiling height, we have about 2 m in the old parts (1.9 m under the ceiling beams), and in the extension that contains a larger living room, it's about 223 cm if I remember correctly. If you are not tall, the ceiling height itself is not a problem. Visually, how it is experienced depends on many things, but if there are windows on two walls, it is likely not a problem.

 

[ferroknegarn]

Is the area above used, or is it possible to reinforce the floor structure from above?

Regarding ceiling height, we have about 2 m in the old parts (1.9 m under the ceiling beams), and in the extension that contains a larger living room, it's about 223 cm as I recall.
If you are not tall, the ceiling height itself is not a problem. How you perceive it visually depends on many things, but if there are windows on two walls, it's likely not an issue.

There are bedrooms on the upper floor and that floor will remain as is.
There are windows on 2 walls.
Checked and have about 236-240 cm in ceiling height in the remaining rooms on the ground floor. So it might not be something to worry about.

 

[z_bumbi]

I would save as much ceiling height as possible, especially if it doesn't have to be lowered.

 

[Messier1994]

I would save as much ceiling height as possible, especially if it doesn't have to be lowered.

Same, but maybe it's related to height. Difficult situation though if the floor above the joists has to remain — because I think 145s alone are too weak. I remember that you have to go up to 200+ when it's wider than 4 meters.

 

[ferroknegarn]

According to Träguiden, the maximum free span is 4.4m cc400 for 45x220. It will probably be to go with that and hope it works well.

Or can one consider some other material/construction technique instead?

 

[Oldboy]

Then it's steel beams that are necessary?
It feels very overkill when regular studs work just fine.