Floor leveling

[cdbe]

I've knocked through to the new extension slab and need to level through to the existing timber floors. I'm reboarding the timber throughout so that will be made perfect. My laser level tells me I need to raise the timber floor by 10mm to come to the top of the highest point of concrete (slab is within 10mm throughout). My question is, what's the best (easiest to use) leveling compound. The concrete is a fairly finely tamped finish (see photo) so I think I'll need a bit of coverage for that, so how much, as I'll have to add that to my timber floor height, I'm hoping no more than 3mm but would go to 5mm in case any high spots?

Slab is 30m² running through to about 25m² timber.

Recommendations on a couple of good products and approx quantities etc would be appreciated. I have a big paddle mixer, spiked roller and I've managed a few smaller areas in the past.

Flooring will be glue down lvt.

 

[dazlight]

You need at least 18mm ply on the joists.

 

[cdbe]

I've already bought 22mm flooring grade chipboard, joists are 450mm centres.

 

[dazlight]

So when that’s down what’s the height of the chipboard to the screed sub floor ?

 

[dazlight]

If the screed is 10mm higher then over board the chipboard with 9mm plywood.

 

[cdbe]

Thanks. I wasn't aware that chipboard on its own wasn't suitable, I am now. I'm leveling all the joists so should be able to factor that in to make the chip and ply 15mm higher than the slab to allow for the self levelling.

What's good for the concrete? I think I'd need it between 5 and 15mm for full coverage. Something that literally, other than a bit of pushing around with my spiked roller, does all the work for me!

 

[dazlight]

you could use Mapei renovation if there are no damp issues

 

[cdbe]

you could use Mapei renovation if there are no damp issues

So according to the MI's this stuff is suitable for chipboard! I was wondering how (with my limited experience) I would get my screed (on the concrete) to the exact height of the chipboard/ply (the join will be 6m long). It would be easier if I ditched the ply and ran the screed throughout - over chipboard and concrete in one pour, I don't think I've got the depth to manage chipboard/ply/screed.

I've looked on the flooring forums and it's a bit mixed, one even said it can't go on chipboard and it's a translation error! The chipboard will be down and walked on for months before it's screeded so the shinyness will be long gone.