Replace upstairs flooring

unhappyBB

My upstairs "floorboards" are actually sagging, super creaky chipboard. I'm going to try to replace them myself but my question is what should I replace them with?

I'm thinking of using 18mm ply sheets but it was pointed out to me that without a tongue & groove these could also squeak. What do you guys think?

Also, while the floor is up I'd like to reduce the noise coming from the sitting room below. Should I just fill the floor cavity with standard insulation? Has anyone else done something like that?

Calahonda52

You need to strengthen the floor joists first to eliminate the sag, maybe double up every second or third joist with strips of 18mm wpb ply screwed to side. add some additional noggins as well
Then fill with dense, sound reducing insulation and screw down the 18mm wpb ply.
If ceiling has down lighters from below then don't bother with insulation.

builder007

In my case

- The house has no sound insulation at the moment.
- Solid pine wood T&N was laid on bare joists (no rubber strip)
- There is no rockwool in the cavity between the joists

If possible at all I would like to avoid ripping solid pine planks (to put rubber and rockwool) but I'm worried that I will waste money and time if I don't do that.

My current thinking is to leave everything as is and ADD the following:

1. Put some sound proof rubber mat (6mm) and seal with acoustic tape the connections.
2. Put a layer of plywood or something similar on top of it (please suggest alternative)
3. Put another rubbery underlay for tiling (acoustic)
4. Tile with wood effect tiles