Best stuff to level a concrete kitchen floor

[Kal Ico]

I'm seeking advice on how to level an ever-so-slight difference in level across a concrete kitchen floor.

The kitchen has been extended many years ago (1980's I'm guessing). The change in levels is gradual, but I reckon if I put laminate over it, then the boards will flex into 'the dip' slightly. Levelling the kitchen units isn't a problem.

To make things worse (maybe) there is proper old lino stuck down with super-sticky adhesive, so I am toying with whether to try to put something over the top, rather than scrape back to the concrete underneath.

Anyone got any experience of such things please? (I have only heard of self-levelling compound, but never used it).

Thanks

[Andy Burns]

how slight is ever so slight?

I presume you don't fancy the laminate running parallel, rather than perpendicular to the slope?

Lots of people imagine the word "self" in "self-levelling" compound, it's not really there, it flows to a certain degree, but the last few mm is down to you pushing it about with a trowel.

[R D S]

Waves hand...

I've an empty shop I want to sell and wondering what to do about the absolute bollocks of a job we did of the floor some years ago.

Smash it up and start again or plonk another layer on top and try to do a better job. What's a realistic minimum thickness you can get away with with this stuff?

[Kal Ico]

[snip]

Thanks Andy, that's helpful.

I reckon the change in height is about a cm, over roughly half a metre. It's more of a hump in the floor, running from one level, concave up to the next level (the hump). From the other side of said hump it runs flat.

I think I can see what you're suggesting about having the laminate across the kitchen (it's a typical UK long, thin kitchen, especially now extended). That could sort the problem, but would look a bit rubbish I reckon.

I thought about putting vinyl down. That would sort the problem of flexing boards, but the 'hump' would still be discernible.

WRT the self-levelling, I wonder if I could smooth it out with something long like a speed-skim, such that it filled the concave shallow. I'll have to research how viscous it is and whether it would just start to run away. I'm guessing that it can taper to a fine edge, that wouldn't be noticeable under laminate. Having the every-so-slight rise in the floor level won't be as bad as having the boards flex when walked on.

Thanks again.

[John Rumm]

There are several different types of self levelling compound, some are more "liquid" than others. Farrow and Ball stopgap 300 is very liquid and will largely self level so long as you have at least 3mm of coverage. (you do a final smooth with a spiked roller). You need to use the proper primer and follow the instructions.

(see the videos on the site)

The Wickes latex self smoothing product seems pretty good IME.

(don't bother with those videos :-)

You can feather them out to nothing if required (say filling a hollow in a floor the rest of which is level), but usually its easier to coat the whole floor. Fill deep hollows in a separate operation first.

If doing a whole room that is empty, then I would use a laser level to stick a line around the room that is about 3mm higher than then highest point. Make up a screeding bar on a handle that is not too far off the width of the room. Mix up enough, to do the whole room (depending on size!), dump it in a line at one end and push into the corners with a trowel. Then drag the puddle out with the screeding bar, using your level marks as a guide.

[Clive Arthur]

<snip>

There's an old type of vinyl flooring made by GAF Corporation (and others) which contains asbestos, so take precautions if you're not sure.

[John Rumm]

Marley floor tiles also contained it at one time.