Self-leveling compound on garage floor

[fsn]

Inspired by another thread, I thought I'd tackle my second workshop garage and finally paint the floor.

It's the basement and there's a cast ceiling above. Some concrete has dripped from the ceiling casting, and I can easily grind away those lumps with an angle grinder and a sanding disc from Biltema.

But when leveling the floor, I realized I had two annoying low spots about 1-1.5 cm deep, so I'm considering leveling the entire floor. But which self-leveling compound should I use that becomes hard enough to serve as a proper garage floor, as hard as concrete?

I leveled a smaller area this summer with some Biltema outdoor leveling compound, Litoliv or Litoflex or something like that, but it didn't turn out as hard as I expected. Porous stuff that broke apart when you put a knife point into it.

 

[salkin85]

Finja 520 industri, should do the trick.

 

[Liteavvarje]

The crumbling was probably because it didn't stick properly to the concrete, concrete absorbs heavily and if there's too much of it, the flow doesn't adhere, it just sits on top. The concrete must be absolutely clean, no dirt at all, and then primed two, maybe three times to get a grip into the concrete. Then the flow will probably stick as well, but it must not be too thin.

 

[fsn]

The reason it crumbled was probably that it didn't adhere properly to the concrete, concrete absorbs heavily and if there's too much of it, the flow doesn't stick, it lies on top. The concrete must be absolutely clean, no dirt whatsoever and then prime two or maybe three times to get a grip into the concrete, then the flow will probably adhere too, but it must not be too thin

I'm quite sure it was perfectly fine. The concrete was clean, poured a month earlier. Primed once around and an additional round with a brush right before the flow. Flow about 5-8mm which shouldn't be a problem.

EDIT: http://www.biltema.se/biltemadocuments/manuals/36-8342_man.pdf

 

[Liteavvarje]

Then you have done a proper round, what amazed me was that it crumbled as you say. Now, I'm not really sure, maybe someone else here knows, if the concrete was too new for primer or something, too damp, it can take a long time for the moisture to leave, just a thought, not sure it's true. You apply primer, the concrete is relatively new and damp, the primer can't be absorbed by the concrete and take hold there, there could be a vapor pressure from underneath pushing up, so nothing holds well. This is just a hypothesis and not something I've experienced during pouring, there might be something to it, the guy in Russia can't ask.

 

[fsn]

Then you have done a real lap, what puzzled me was that it crumbled as you say, now I am not quite sure, maybe someone else here knows, if the concrete was too new for primer or so, too damp, it can take a long time before the moisture goes out, just a thought, not sure if it's true, you apply primer, the concrete is relatively new damp, primer can't be absorbed by the concrete and bond there, there's a vapor pressure from below that pushes up so nothing bonds well, this is just a hypothesis and nothing I've experienced when pouring, there might be something in it, the guy in Russia can't ask

No, the concrete wasn't too fresh. The primer absorbed properly and dried in a few minutes, hence a few additional rounds with primer.

The leveling compound adheres to the concrete but it's soft, way too soft to be used as a painted floor. I wouldn't hesitate to lay, for example, garage tiles on it, but it wouldn't work as a painted surface.

I will try a bag with the Finja suggestion I got above. The alternative is to just sand down the remnants from the slab casting. The rest of the floor is power troweled with a helicopter during the casting. Not a super fine surface directly but good enough for a mediocre floor paint, but then I have to live with the level differences.

If I pour leveling compound, I was hoping it would be good enough that it wouldn't need sanding, which I think seems reasonable, any opinions on that?

 

[schmakita]

If 520 unexpectedly doesn't do the job, you can always top it with 540 or 560 on top of that. But it feels crazy overkill.