creaking floor issue

aggi

Good morning, I have found offending nail in my internal wall. It creaks terribly. Please advise me how long the screw should be to replace the nail to stop the creak and what can I expect under the floorboard in that precise place? a supporting beam? This is how I found this nail by the way, I have not attempted to take it out at all. Thank you for advice

Mutton_Geoff

Looks like normal studwork for a partition wall. What is underneath the timber? I'd measure how high that floor batten is (50mm/2"?) and just screw a 5/80mm screw next to the nail if you can't get the nail out. I'd be worried why it wasn't hammered in all the way and investigate what is below it before putting a screw in. If you can get some talcum powder in between the batten and floor, that helps stop creaking.

aggi

Thank you, the batten is about 15mm above the floor. This was filled with expanding foam, which I cut out to see the nail. I guess strip of wood wedged in with powder on it would be good idea? 
At the minute it feels like it was designed to creak and drive me mad.

troffasky

Has the floor dropped, whilst the stud wall has stayed in place? If that's the case then maybe the floor should be investigated.

aggi

When skirting was taken off the space has been filled with expanding foam. no gap between foam and floor visible. what happened before not sure as we just moved in. property is 25 years old and build to a terrible standard as we are now realising. we have now added some 10mm woodstrip and screws and creak has improved massively.