Correcting Floor level

[tagb61]

Hi we just had some work done by a builder in our old victorian two up two down. This has a small room on the back with a concrete floor, the old scullery I'd guess, it's about 3m by 2m. We are fitting a small galley kitchen in there. They have replastered, fitted new windows, added electrics and pipework, and they also installed a subfloor of chip board over 25mm of celotex/battens. But it's not very level. It has a small fall from one end to the other, which is ok, but at the one end it dips down about 20mm across the width of 2000mm which is very noticeable.
The builder says it's fine as the kitchen units on either side can cope with the unevenness using leg adjustments, which they can, but down the centre of the galley kitchen you can really tell that the floor tilts at one end.
He will not make it good, so we have decided we need to do something about it.

As far I can see, we have two options.

Rip the floor out, lay down some screed over the floor in that corner, and put down the timber battens/celotex/chipboard again. Very time consuming !

Screed over the chipboard to level it out.

Option two is quicker and easier but is it even possible ?
Does anyone have any alternative suggestions ?

Thanks

 

[dazlight]

You can use a screed compound called ta level flex. Will need priming 1st. You also might have to put a layer of 6mm ply down as it won't stick to certain chipboard. Ones with oils in.

 

[tagb61]

Thanks dazlight, that sounds ideal.
It's the green moisture resistant chipboard for use in bathrooms/kitchens.
I'm fairly practical, but is this something for a expert to tackle ? If so which trade would be able to do it ?
Cheers
Tony

 

[dazlight]

Go to a local flooring company. Or look on yell.com. Should only cost £80-£120

 

[chappers]

You can use a screed compound called ta level flex. Will need priming 1st. You also might have to put a layer of 6mm ply down as it won't stick to certain chipboard. Ones with oils in.

Interesting, they make no mention of that in their own tech data, they say it can be applied un-primed direct to chipboard. I am about to actually use some on a floor and was sceptical about using it on chipboard direct, particularly as it has been down a while and walked on quite a bit so was going to lay ply on top however I wasn't going to bother priming.

 

[dazlight]

If oils on chipboard it won't stick. Also prime every time is my rule. Ardex ba says no primer needed but then you read the small print