can't get nails up from floor!

[Chin85]

hi all

i'm really struggling to lift the chipboard on my suspended floor.
whoever installed it has used a flat head nail that seems to have a screw thread.

anyone ever come across this before and have some tips on how to get them out?

i thought it would just be a crow bar jobbie but after realising they are screwed into the joists i just cannot understand how to remove them (or how someone would have installed them). There is no fitment for a screwdriver or anything - the head of the nail is totally flat.....

thanks

 

[Burnerman]

It sounds that they are Gripfast or Ringshank nails....are you trying to save your floor?
John

 

[Chin85]

wanted to lift it to install some insulation between the joists. very worried about damaging the joists by trying to remove them...not worried about the chipboard but don't want to split the joists.

from the sound of your message it seems like they might be best left where they are and i'll install another radiator!!

 

[London Mike 49]

You could try one of two ways

1. With a electric multi tool and a narrow metal cutting blade fitted, just go deep enough to take the nail head off and then lever the board up.

2. Use a dremel tool to grind the head off the nail and then lever up the board.

Mike

 

[Burnerman]

In my situation, the chipboard was wrecked.....the ringshanks had gripped the chipboard too.
To avoid damage to the timbers and ceiling below, I used a hole saw to drill around the nail shank and pulled the chipboard away. With that gone, I ground the nail off flush with the joist.
The new floor was screwed down.....
John

 

[Chin85]

great advice guys thank you.
i'm going to go with the hole saw and then grind the top of the ******* nails off. The nails are so low in the chipboard it's hard to get anything underneath them at all.

Once that's all up i'll buy some user friendly nails to install the replacement plywood!!

 

[Burnerman]

On thing which intrigued me on my job was the fact that the ceiling below was lath and plaster - yet whoever had fixed the floor down had caused little damage (or maybe the ceiling had been skimmed after - I just don't know.)
Anyway, the replacement was 18mm chipboard, 8' x 2' T&G, screwed down with 50 x 5 CSK screws.
Good luck with your project!
John

 

[Chin85]

which leads on to my next question John...i'm a little put off by chipboard because the current stuff sounds really naff (hollow) and it creaks like hell.
granted the current stuff isnt T&G...but i've been looking at 18mm ply T&G.

Is your T&G chipboard OK/creak free etc.?

 

[Burnerman]

I guess any boards will creak unless they are well secured - I'm not that keen on chipboard but my last project was using 22mm water treated stuff. Heavy as hell and very sturdy.
This was in an extension though so I wasn't governed by the thickness of the existing floor. Again, screws were the order of the day.
Whether ply is better for sound proofing I can't comment but I'd doubt it - I would pack celotex or similar between the joists though, avoiding any gaps of course. Any joints in the sheets should be supported on a timber noggin or the joist itself.
Are you heading for laminate or carpets later?
John

 

[Chin85]

Carpeting after with a nice thick underlay!
Thanks for help

 

[vinn]

Use a "roughneck claw end pry bar" from toolstation @ £7. Angle the claw end and drive it in with one hammer blow.
Is your c/board definitely T&G?
Is it glued down or edge glued?
Are all join on joists, and boards laid across joists?

Nothing wrong with c/board.

 

[Chin85]

Thanks. I don't believe any of it is glued. Should it be?
Looks like all those horrible nails are on the joists.

Current stuff isn't T&G. Is that why it's creaking?

 

[Deleted member 174758]

Once that's all up i'll buy some user friendly nails to install the replacement plywood!!

Or just use screws?

Thanks. I don't believe any of it is glued. Should it be?
Looks like all those horrible nails are on the joists.

Current stuff isn't T&G. Is that why it's creaking?

It creaks if it isn't T&G, when all the joints aren't supported and if (T&G) isn't properly glued. I've also seen examples where the joist spacing was too wide and the nailing/screwing pattern has been inadequate (i.e. should be 150 to 200mm centres). Personally I prefer to screw it and to work with 22mm or thicker P5 (water resistant). Best make is probably Egger if you get a choice - miles better and more durable than Kronospan in my experience