Laminate over floorboards AND uneven concrete

[Captain-Y-Fronts]

We're refitting our kitchen in a Victorian terrace. The floor is three-quarters floorboards (covered with hardboard) and one-quarter uneven concrete.

The previous owners had fitted ceramic tiles, but these had all cracked. The floorboards are all sound, but the concrete is very uneven with about an 8-10mm deviation over 2 metres. And judging by the hollow sound across certain sections I would guess that some of the concrete has been laid on top of timber!

I don't feel inclined to lay screed on top as we have kids and can't really spend another couple of weeks without a kitchen just while the subfloor dries.

I was considering laying 2 x 2 on 40cm centres over the entire floor with 18mm chipboard on top. Are there any other solutions that I might consider?

Many thanks,
Alex

 

[mattysupra]

Hello and welcome to the forum.
If you dont want to go for levelling compound ( which would only need 48hrs before laying laminate on top), then this is really your only option. All tho i would lay plywood and not chip board. Its a lot more stable and stronger. I would also lay dpm plastic / moister barrier over concrete area. Hope this helps.

 

[Captain-Y-Fronts]

Thanks very much mattysupra.

48 hours doesn't seem so bad. I just got worried 'cause the laminate flooring guides all say 1 day per mm... It seemed excessive, but I had no experience with leveling compounds - so there we go!

Given that there is no shortage of headroom (more than 3 meters), in the end we went with the baton subfloor, taking the opportunity to hide some of the pipes and wires round the edge of the room.

The plywood certainly seemed more suitable than chipboard (we used plywood in our bathroom floors under vinyl tiles) but unfortunately it was beyond our available budget, and our local DIY store had a special on kitchen/bathroom grade floorpanels - so we went with that.

Once again thanks for your help!

 

[mattysupra]

The 1mm a day rule Is for sand and cement bases/ screeds etc. Levelling compound works different.