Floor Boards Under Carpet

All floor are meant to have a cushion between the underside of the floor board and the joist this can be anything from silicone to D4 wood glue and then screwed or nailed with Ringshank nails I prefer the D4 wood glue and screws as the D4 glue expands and gives you a better bond between joist and board

If the floorboards gave been nailed, then there will be movement, screw them down instead. It's the joints that move and that's what's creating your noise. Before the carpets go down, check the joints and maybe pour in some pva glue, to stick the joints together, lessening the noise..

This all depends on how old the floor boards are ? And what the type of boards are ? are they Interlocking chipboard or wooden floor boards ? The most common course of noisy flooring is - Plumbing or electrical work ? These trades never fit flooring back correctly ! In either case there no quick fix. The offending boards need lifting to inspect what underneath? Then fitting back correctly! If it’s chipboard? sometimes this needs full replacement , gluing and screwing like the previous comment said ( this can only be achieved by replacing the full offending area. Hope this helps ?!

There could be many reasons it’s making noise, firstly they may not have glued the floorboards which gives it movement when weight is on them which could be causing the noise or they may not have put enough fixings in it which again is causing movement

Assuming the joists are solid and the boards are still bouncing and noisy it’s obvious that they haven’t been fixed down properly, the boards have to be screwed on every joists.

Hi, we need to keep in mind that we talking about old priorities. It's really hard to find from where the noise it's coming for. When we moved in to a new propriety the stairs were doing the same irritating noise, their cane to fix it but after a wipe the noise came back. So the to solve the issue is to chek the entire floorbord and probably replace it and the noise will go. It will cos you some mine but my opinion it's the only way.