Question regards levelling an uneven chipboard floor

[The Riviera Kid]

Hi folks,

I've just been reading mattysupras post above regarding levelling an uneven wooden subfloor. It all sounds pretty do-able, but I have some questions.

Our floor is a floating floor and consists of concrete, a DMP, polystyrene blocks and chipboard tongue and groove panels placed directly on top of the polystyrene (no joists or anything). The floor itself is quite uneven in places and seems to rise and fall in places by as much as 10mm.

First of all, I'm wondering if it's worthwhile hiring some sort of industrial sander to take a couple of mm off the high spots in the tongue and groove before fastening plywood on top, or is this likely to weaken the tongue and groove too much?

Secondly, regarding caulking round the edges. I'm wondering how close I should take the plywood to the wall, to allow for expansion but not leave so big a gap so that the caulk cracks. I've read that caulk is slightly flexible (hopefully allowing the floor to expand and contract), but appreciate you can't fill massive gaps with this stuff.

Thanks in advance folks.

 

[mac391]

If your woodchip panels rise and fall by 10mm in different areas i would say there is an underlying problem, one that sanding will not fix.

Can i ask,, is the floor in a conservatory and what are you planning to lay on top??

Has it always been like this?

What is the plywood for ?

It sounds like your boards are warped so it could be a moisture problem.

 

[The Riviera Kid]

Not a conservatory, in the living room, it'd be laminate purely as it's cheap and easy cleaned with kids running about the place. There's currently laminate down, but it's not sitting perfectly due to the lumps and bumps.

Yep, but harder to spot until rencently because of previous carpet and the position of the humps and bumps - the big ones are hidden in the only places sofas can go.

Plywood - just following mattysupras instructions in the sticky post

Don't think it's a moisture problem, I think it's more likely a cowboy builder problem. The house is a 1990 ex housing association property, which we've lived in for 10 years but only bought recently, and there's examples of comedy building work all over it. I was loathe to do anything major about it while we were renting, but now we've bought I'm looking to sort it all out. I suspect if I pull up the boards, the DMP and the polystyrene blocks, it'll simply be uneven concrete or some rubble. Obviously with unlimited time and cash I'd rather do it properly by taking everything up, levelling and replacing, but with kids, work etc, if there's a quick fix which gets a decent result in a day, then I'd be keen to do that.