How Fix a Chipboard Creaky Stair Landing

[VeronicaMP]

I have recently removed the carpet from my stairs, sanded down and painted.

There is a small landing (pictured), before the main landing/hallway which I am stuck on.

I had initially planned on laying a thin sheet of plywood over, painting it to match the stairs, then the runner of the stairs would cover much of the area of the landing anyway.

However, it is very very creaky.

I have read many a post about fixing creaking chipboard - pull out the existing nails and use appropriate screws. However, these nails are so far down I cannot access them to pull them up (see pic)?

What are my options to stop the creaking - without ripping the whole thing out / pulling up the skirting (based on the pics that doesn't even seem like an option)?

Can I screw down next to the nails with the "tapping" method I have seen online (hollow sound means no joist, solid sound means a joist).

Can I then just glue down the plywood on top or does this need to be screwed?
https://photos.app.goo.gl/nm8ixWm8LK9QdijF6

 

[CBW]

It doesn’t look too difficult to remove the skirting boards, I would remove them lift the flooring to see what’s going on underneath. Adding support where necessary. You could try the last method you mentioned, if you’re confident that there’s no wires, pipes etc and just following a joist - however this could still end up with the same result.