# Some suggestions for a very uneven concrete floor



## jklingel

psilva8 said:


> My goal is not to make the floor level, however, make it plumb.


 One of us is confused. Level is all in a horizontal plane, whilst plumb is a vertical plane. No? Do you mean "flat, but not necessarily level"? This may or may not be an option for you, and nothing is going to be cheap. I had a basement room that had as much as 5/8" vallies from the one spot I called "0". I glued a variety of plywood shims to the concrete, in a 2' grid. I then laid down two layers of 1/2" OSB, staggered joints, glued and screwed together. Over that, I installed fake wood floor. It's been there for 11 yrs now, and no issues I am aware of. If you wanted it more solid, you could Tapcon, or whatever, the plywood (I won't use OSB again) to the concrete here and there. If you have room and desire, insulate the floor with foam board first.


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## psilva8

jklingel said:


> One of us is confused. Level is all in a horizontal plane, whilst plumb is a vertical plane. No? Do you mean "flat, but not necessarily level"? This may or may not be an option for you, and nothing is going to be cheap. I had a basement room that had as much as 5/8" vallies from the one spot I called "0". I glued a variety of plywood shims to the concrete, in a 2' grid. I then laid down two layers of 1/2" OSB, staggered joints, glued and screwed together. Over that, I installed fake wood floor. It's been there for 11 yrs now, and no issues I am aware of. If you wanted it more solid, you could Tapcon, or whatever, the plywood (I won't use OSB again) to the concrete here and there. If you have room and desire, insulate the floor with foam board first.


That's it, I'm never watching holmes on homes again.

Thanks for the suggestion. My #1 option is to pour a levelling mix over the existing concrete. There are way to many dips and doodles to try and shim plywood.


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## ben's plumbing

I remember a product called ardex that was used to do exactly what you want ..and it was not that expensive..and dryed like a sheet of glass self leveling...


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## jklingel

ben's plumbing said:


> I remember a product called ardex that was used to do exactly what you want ..and it was not that expensive..and dryed like a sheet of glass self leveling...


 I wish I'd known of this in 2000. I asked 3 floor places, and none of them ever heard of anything that would really work. I knew there had to be something.... 135 shims, from 1/8" to 5/8" thick, 2"x2", was a major PITA, but the floor is in and doing fine.


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## mobiledynamics

Cheap but needs work.....deck mud

I like Mapei Ultraplan M20. $40 a bag.......pours up to 2", works very well.....but get's expensive.....You need to have 3+ men to mix, pour, all in one shot, but its great stuff. I wholeheartly recommend it if budget allows.


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## abracaboom

You could use plain mortar to fill in the valleys just short of level, and finish off the floor with self-leveling cement.

Mortar will stick well if the old concrete is clean and wet.


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## jklingel

Caboom: Don't you usually have to acid etch and/or scruff up the old concrete first? I've never done either, but after a concrete company did a pathetic job pouring the floor at my son's, I called to ask about "fixing". They said that concrete will not satisfactorily stick to concrete. However, if their knowledge was anything like their work, neither was worth Jack Stink.


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## abracaboom

The cement in mortar will surely stick to the cement in concrete, especially if you get the old concrete a bit wet first so it doesn't suck up all the moisture off of the new mortar. The old concrete has to be clean also. I'm not an expert on the cleaning part, but I think that hot soapy water with ammonia and a hard brush should do the trick.


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## jklingel

OK. thanks.


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## oh'mike

Most self leveling compounds require a primer to ensure a good bond---sand or pea gravel can be added to fill thicker pours.

Jiff Set can be mixed with Linewebers liquid latex for a good bond on the first coat--

SLC is to soft for use as a finished floor and must be topped with tile--sheet goods or other wear surface---


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## psilva8

Guys I really appreciate all these suggestions. It's gonna take me a bit of time to do some research on them.


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## oh'mike

Every maker has a technical help line---when you find a promising product---call them and get the final answer from the horses mouth---


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## Nailbags

If you got dips and peaks in your floor with zero cracks you can use this works great.
http://www.edisoncoatings.com/html/Self_Leveling_Concrete_Floor_T/self_leveling_concrete_floor_t.htm
Best of luck!


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## maxwardle

*levelling kitchen floor*

this is the predicament that i have below and have seen your comment on self levelling compounds elsewhere can you please advise me on the need for cleaning before use on a concrete surface , should i use a plastic dpc , are their 2-3 hour foot traffic and 1 day going off claims real
(i have a floor that needs leveling that in some areas will need a screed/ compound or polymer upto 50mm deep in some areas , now the are products on the markets that claim that they can cope with leveling on such a scale to such depths and shall be able to be walked upon in hours and worked upon in a day such as , wickes deep base *levelling* compound and cempolay deep has anyone used either of these products, do they live upto their claims , any feedback greatly appreciated ) thank you for your time and consideration max


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## skitter

I would use muriatic acid to clean the existing concrete first, then brush on a latex concrete aditive and then while it is still wet, pour the leveler or concrete on top.

BUT, Im not a pro and know just enough to get myself in trouble (lol)

Wear a proper face mask for vapors, eye protection and long gloves (as well as long sleeves and pants) and ensure good ventilation while working.

How will the floor be used once it is "flattened"?


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## Creteexpert

We've poured over floors like this many times to "level" them out. We use a 3/8 stone 3500 psi concrete mix delivered in a concrete truck. 1 yard of concrete will cover 220 sq. ft. at 1.5 inches thick. We vacuum and wash the existing concrete to clean it, then use a primer called Weld Crete. I would recommend pouring 1.5 inches thick over the higher spots, I don't like pouring thinner than that, which means your overall coverage might be around 160 sf per yd (2" thick average over entire floor).

Concrete costs about 100.00 dollars per yard, add some fibermesh 7.00 dollars per yard and most concrete companies have a minimum charge of 4 yards for a total cost of 428.00 dollars plus tax for 640 sq. ft. of coverage. 

I would hire a concrete floor contractor to place and finish the concrete, estimate 1.00 dollar per sq. ft. labor.

This should be much less than using a self leveling bag mix, we also use Mapai & Ardex products, they are expensive unless you're leveling a floor that's only out 1/2 inch or less.


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## robs660

You can hire a gypcrete contractor. Thy can pour 1/4" up to 1 1/2" and it's fast! Find a contractor in your area and run with it


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